EFI modifications

[turbocity tom]

I am looking for a few more "test Subjects" for the recalibrated fuel pressure regulator that we produce. So far the test results are very favorable but we would like some more testing. The parts would be provided at no charge in exchange for some data collected. We would like to have riders that use the ST regularly and may have some feel for the changes that we can produce. We need a few more STock bikes, and maybe a modified one. If you are interested let me know.

Tom

[crazykz]

Hi Tom,

I'm not in the CA area but may be interested in testing. Couple questions.

1. Would it void my warrenty?
2. How difficult is the install?
3. Would I being doing the install myself?

Curt

[wjbertrand]

I am looking for a few more "test Subjects" for the recalibrated fuel pressure regulator that we produce. So far the test results are very favorable but we would like some more testing. The parts would be provided at no charge in exchange for some data collected. We would like to have riders that use the ST regularly and may have some feel for the changes that we can produce. We need a few more STock bikes, and maybe a modified one. If you are interested let me know.

Tom

I'm intersted, what do I have to do?

[unSTeady]

So am I, interested, that is!
Do you ship to Sweden?

[Hewhois]

Greets!

Pending answers to Curt's questions, I may be interested as well. Also, would it improve MPG at high speeds? What exactly is your goal with the EFI?

The ST1300 is my primary ride. I commute to work on it, 375 miles per week just commuting. Average about 500-600 total miles per week, sometimes more.

[ilvtoride]

I am interested...the previously listed questions hold for me also :03biker: ...

Paul in NH

[rob.uk]

Hi Tom,

I have an '02 ST1300 that is out of warranty. I would be very interested to be a test pilot. In particular does your regulator smooth out the surging that can occur as you unload/ load the engine while changing gear? At present I find the only technique that gives smooth power delivery is never to let the engine speed fall below 2000 rpm during gear changes.

Many thanks,
Rob

[turbocity tom]

Thanks for the responses, Let me answer some of your questions.
1. The modification should not void any warrentty but that is up to your local dealer to decided. I have run the mod on my ST for about 10K with absolutly no ill effects.
2. It is very easy to install, it replaces the original fuel pressure regulator.
3. The difference in drivablity is very noticable.
4. There is no permanent change to the system.

The basic idea is that the EFI system as designed to meet the emission reqirements is too lean. A small change in fuel pressure eliminates the drivablity problems.
I have an injector test machine that i can accurately recalibrate the fuel prssure with a tool that i have designed.
I would like to do the testing in the US as it would be easier for us.
We can talk individually if interested at 714-639-4933.
Thanks Tom

[ilvtoride]

Tom I have an ST in NH that is wanting more pressure.

Paul :03biker:

[rob.uk]

Talking to Tom by 'phone just now, these devices are in production. I just ordered one from www.turbocity.com (http://www.turbocity.com/) -> Odd Stuff -> Honda ST1300 Fuel Pressure Regulator.

They are $129.95 plus P&P, picture attached.



The claimed benefits on Tom's web site are:"This Honda ST1300 fuel pressure regulator is custom recalibrated to improve the overall drivablity and eliminates the troublesome quirks of the EFI system. Easy install and is a direct replacement for the original unit.

BENIFITS
-Idles at 750 rpm very smoothly-
-Accelerates without hesitations or sags-
-Will pull a lower rpm in a higher gear-
-Eliminates cruise surge 3500-4500rpm-
-Smoothes throttle on/off response-
-Softens driveline "clunk" and "snatch"-
-Can be tuned for exhaust/intake modifications-
Weight: 0.50 lbs."

I'll post a report after I've fitted mine. I would certainly like to smooth out the driveline clunk and snatch that occurs below 2000 rpm, and I'd like to smooth out the throttle "on off" response.


Regards,
Rob

[NormanPCN]

Tom,

In a previous post here or on MSN I believe you said that fuel economy is reduced which makes sense with an increased fuel pressure. How much reduction? Approx how much are you increasing the fuel pressure?

[turbocity tom]

Norman.
The exact pressure for the average ST is what we are testing for. We have run them in the range of 56-68 psi.
The decrease in fuel ecconomy appears to be about 1-2 mpg.

Thanks Tom

[Marshal_Mercer]

Tom,

In a previous post here or on MSN I believe you said that fuel economy is reduced which makes sense with an increased fuel pressure. How much reduction? Approx how much are you increasing the fuel pressure?

Norman:

I have one of Turbo_Tom's regulators installed on my ST. The pressure is set to 58 PSIG. Although I only have 140 miles on the modification performed last Saturday, I can say without hesitation (no pun intended) that my '04 now runs the way that it should have from the factory. There is clean power to be had from 1,800 RPM to redline. I rode around this evening at 1,800 RPM in fifth just because I could. Clean, strong acceleration was a throttle pull away. There is no longer a (minor) flat spot at 2,200 RPM, nor a more noticeable one from 3,400 to 3,800 RPM. I also reved to 7,000 RPM in second gear and cruised for a while. "Turbine" smooth is not too strong a description for what I felt through the gas tank!

Gas mileage may or may not have been affected. I see five bars lit at 140 miles. I'll let you know more after I refuel.

Marshal

[dond]

For those with heat concerns, this may be the fix?

Group buy/STOC deal maybe?

[craig55123]

Marshall

Did it fix the on/off nature of throttle response?

Thanks.

Craig

[GRN]

For those with heat concerns, this may be the fix?

Group buy/STOC deal maybe?

Like that idea... better low end would be nice, and if it fixes the initial throttle response I'm all over it :rolleyes:

:biker: :03biker: ............. :04biker:

[Mellow]

Here's a question... will this affect emissions and passing an inspection? I guess if you CA guys can get it passed it'll be okay for everyone else...

[dond]

We Californy guyz don't have no STeenking inspections :p:

[Marshal_Mercer]

Marshall

Did it fix the on/off nature of throttle response?

Thanks.

Craig

Yes, it did. No more jerkiness, except for the usual (minor) driveline movement.

Marshal

[Marshal_Mercer]

Like that idea... better low end would be nice, and if it fixes the initial throttle response I'm all over it :rolleyes:

:biker: :03biker: ............. :04biker:

Low end is better. Mid-range is better. Top end keeps on pulling! Neat.

My bike now has no "character" -- in the Harley sense, anyway ;) I may have to put some rocks in a can to improve the "feel".

Marshal

[Marshal_Mercer]

Here's a question... will this affect emissions and passing an inspection? I guess if you CA guys can get it passed it'll be okay for everyone else...

Haven't had a smog check since the mod, but suspect that as the ST is good for 2008 smog rules, this mod will do little or nothing to change the 2005-6-7 testing outcome. Who knows: maybe its now good for 2010?

Marshal

[turbocity tom]

Next week we are to do some tailpipe emission testing. I will post the results.
I suspect that there will be a very small increase, but should not pose a problem to any state retest (does any state require testing on a bike?)

Thanks for everyones input and support. Tom

[Mellow]

In Texas I've never had a bike emissions tested however they did just start doing it for cars and I've heard bikes aren't far behind...

[turbocity tom]

In Calif there is no retest at this time and I have not heard any plans to start.

I see you have a Wing also, I've been asked to look into this same mod on the Wing.
Do you see any drivablity issues?
Thanks Tom

[Mellow]

I've heard guys say there's a twitchy throttle but it was not as severe as on the ST. I really haven't had a chance to ride the bike much so more miles should give me a better feel for it, I was also taking it very easy for the first 800 miles... Now that I can really rev her up I might have a different opinion on the throttle... I'm thinking I do remember it being twitchy on my '01 Wing. I'll need more time to decide and I'll let you know.

[turbocity tom]

For those with heat concerns, this may be the fix?

Group buy/STOC deal maybe?
Don,
My 04 has never had a "heat problem" any worse than any other bike I've owned. I did vent the front cowl to lower the temp of the pockets. The volume of air thru the head vents has increased and the air temp is less on the legs, but it is still warm not hot.

Tom

[turbocity tom]

I've heard guys say there's a twitchy throttle but it was not as severe as on the ST. I really haven't had a chance to ride the bike much so more miles should give me a better feel for it, I was also taking it very easy for the first 800 miles... Now that I can really rev her up I might have a different opinion on the throttle... I'm thinking I do remember it being twitchy on my '01 Wing. I'll need more time to decide and I'll let you know.
I would like to work with you in the future if you elect to modify.

Thanks Tom

[hippo888]

This device will void your warranty. You are changing an integral part of the EFI system. However, given the pathetically poor knowledge base of the average Honda mechanic, they're never going to figure out that you've done this because...

...the Honda EFI system does not treat fuel pressure as a monitored variable. There is no sensor to detect fuel pressure (the only manufacturer that I'm aware of who does monitor fuel pressure is BMW). The only way a Honda dealer is going to find out you've changed fuel pressure is by identifying the new pressure regulator or testing fuel pressure with an analog meter.

Increasing fuel pressure is not as simple as it sounds (actually it's simple, it's just the effects that can be complicated). The aim is to richen the mixture (the stock hyper-lean, CARB 2008-compliant mixture is the root of the on/off throttle abruptness). If the ST1300 ran an open loop EFI system, increasing fuel pressure would be relatively harmless because the EFI system will not try to compensate for the richer mixture. It would be just like richening the mixture on a carb.

However... and this is a big however... the ST1300 runs a closed loop EFI system. The bike will try to compensate for the richer mixture.

Here's what happens. The new fuel pressure regulator increases fuel pressure. Whenever the EFI system tells the fuel injectors to open, more fuel is squirted in than normal because the fuel is under more pressure than the original setting. The EFI system has been calibrated so that it expects fuel pressure to be at the original setting. With the increased PSI fuel pressure regulator, there is now more fuel in the intake charge. This richer mixture than goes through the combustion cycle and past the 02 sensor. Here's where the problem comes in. The 02 sensor sees that the mixture is rich. The EFI then tries to compensate for this. Typically, it will try to reduce the time that the injectors are open. It will reduce the time as far as the engineers have allowed. However, the increased pressure of the new regulator keeps the mixture rich no matter how far the EFI system reduces injector open time (or else you wouldn't see an improvement in rideability). At this point, did the Honda engineers program the EFI to start changing other combustion variables such as ignition timing?

The EFI system will try to compensate. It will change whatever variables it can to try to get back to CARB-2008 compliant emissions. What the new fuel pressure regulator does is to input so much fuel that the EFI computer cannot correct the mixture. Will running the engine like this hurt it? I don't know. Will running the engine in this condition cause the EFI to give up and just dump the bike into a "limp-home" mode? I don't know.

Am I an expert at EFI systems? No. Do I know what the heck is going on in the EFI when it reaches the end of its adjustment scale? No.

Just be careful. Check your plugs often.

Would I install this regulator? Once I get more time away from work, I'll probably give it a try.

[turbocity tom]

Paul,
The point of this type modification is to improve the drivablity without going outside the limits of what the computer is expecting to see. I work on modifing efi systems everyday and if these modifications are taken to exstreme then you will have problems. I have run this mod for over 10k miles and have had no problems or ck lights with the efi system. I beleive that it is completely safe for the application.


Thanks Tom

[Littlejohn64]

Tom,
Aftyer researching your install instructions, etc., this looks like something I would be capable of doing.
If you still need test bikes (mines bone stock as far as the engine, intake, exhaust, drivetrain) I would be interested. Im in TX, and as mentioned, this may be a solution to the extra heat put out by the lean engine.
email me at
littlejohn_scrcc "at" yahoo "dot" com
if you would like to discuss details.
Thanks!
John

[rob.uk]

Tom has now dispatched the regulator I ordered. I expect it will arrive in the UK next week. Here is a summary of current behaviour on my '02 ST1300 PanEuropean, which has now done 10k miles:



Changing up through the gears:I have to be careful not to roll off the throttle too much, I try to match the engine RPM very carefully to what is "expected". Let the clutch out very carefully etc. If I get it "wrong" there is an almighty lurch as engine braking kicks in when in fact I'm trying to accelerate. I never had this effect on my Bandit 600 which was very tolerant of engine RPM while changing up and dumping the clutch quite abruptly.

Top gear 80 mph and above:No problems with engine surge or speed regulation. Just have to watch out for big yellow boxes with lenses :22yikes: Top gear, slowing from 80mph to 60mph, then accelerating:There is an abrupt change accompanied with a "jerk" to engine braking unless the throttle is rolled off very smoothly and slowly. On opening the throttle again, it's almost impossible to avoid a big "surge" and another "jerk" unless the clutch is slipped slightly. The critical speed for surging seems to be between 65mph and 70 mph. Again, my Bandit 600 showed none of these problems.Low gear, mini-roundabouts/ sharp turns:Almost impossible to avoid engine surging and poor speed control, unless the clutch is slipped and rear brake applied while maintaining RPM above 2500. Smooths out a bit more if you keep the engine RPM above 3500, slipping the clutch a lot - but sounds noisy is hard on the clutch, and has "wheelie" dire consequences if your clutch control is a bit naff. Again, with my Bandit 600 I rarely had to slip the clutch for low speed manoevers, just a bit of light rear brake in combination with smooth throttle.Maybe with my ST1300 being a very early '02 model, Honda have improved EFI on later models. I don't now. Mine might be particulary bad. Anyway, I will report in again some time in the next 2 weeks after fitting Tom's regulator, and touring France.

Regards,
Rob

: bgw1:
BTW - can I have one of these cool icons in Red -
Red ST1300's must go faster to avoid the surging!

[Actionfigurejoe]

Rob, I haven't had the driveability problems you and others have described. No surging or low speed jerkiness. Perhaps there's some variations in the production tolerances of the stock fuel regulator which alter fuel pressure. That could explain why some ST's have driveability problems and others don't?

[rob.uk]

I wonder if there is a problem related to early manufacture which was rectified by Honda in later production. Is there evidence from those with "surging" that this is limited to say '02 and '03 production?

[AgSTreak]

Rob, have you reported the conditions you experience to the dealer? My '03 is positively well behaved compared to yours. I'm looking at this mod as a minor improvement, which may not be worth the slight drop in fuel economy. To you this is a must have.
BTW, if we go for a group buy I'm in. :D

[Mellow]

: bgw1:
BTW - can I have one of these cool icons in Red -
Red ST1300's must go faster to avoid the surging!

How's this?

[nisbeam]

Are there any Dyno charts available to show the difference. It sounds like torque will be increased with maybe some BHP as well. It would be interesting to see a comparison.
I did a mod to my FZ1 with an Ivans Carb modification kit. The effect added torque low down and flattened out the torque curve rather than going for top end BHP. It is a great improvement and adds so much more "driveability". Difficult to quantify but you can feel the difference in the way the bike pulls.
Perhaps this kit will do something similar :)

[Marshal_Mercer]

Are there any Dyno charts available to show the difference. It sounds like torque will be increased with maybe some BHP as well. It would be interesting to see a comparison.
I did a mod to my FZ1 with an Ivans Carb modification kit. The effect added torque low down and flattened out the torque curve rather than going for top end BHP. It is a great improvement and adds so much more "driveability". Difficult to quantify but you can feel the difference in the way the bike pulls.
Perhaps this kit will do something similar :)

From what I understand from Turbo_Tom, the modified fuel pressure regulator does not affect horse power or torque. It just improves the way the engine copes with its delivery of fuel. My rear-end's perception -- underscore perception -- is that my (modified) bike has more power across the board. What my brain believes to be more accurate is that the lack of vibration and hesitation that I once had makes my rear-end notice the acceleration more as there is less to distract my attention.

As Joe Pesci said in My Cousin Vinnie: "...I think that you're gonna be MORE than satisfied."

Marshal

[Carl_T]

WOW Rob.UK!
My red ST must indeed go quickly enough to avoid the surging, as I experience none of what you are describing, beyond the need for a gentle hand upon first throttle pickup in a turn. With a conscious gentle hand I have zero disruption upon throttle pickup, but will have a small to medium snatch if I'm at all careless (depending upon how careless). This touchiness combined with a bit of driveline slop is my only complaint.

A passenger on my bike while I was shifting, might think I had an automatic transmission, it is so easy to keep speed matched to the shift without much of any shenanigans on the Red ST. I find no disruption of the bike upon shifting with no clutch slipping needed whatsoever. While I use common sense caution and avoid doing it, I would not fear the need for a mid turn downshift with the Red ST.

So far there are no steady upper RPM surges either.

STill Tom's regulator intriuges me, If you need another tester Tom I'm game, I ride daily in OK weather, though only about 60 to 80 mi. per day. I'd like to see if the throttle take up in the turns see an improvment.

[Marshal_Mercer]

WOW Rob.UK!
My red ST must indeed go quickly enough to avoid the surging, as I experience none of what you are describing, beyond the need for a gentle hand upon first throttle pickup in a turn. With a conscious gentle hand I have zero disruption upon throttle pickup, but will have a small to medium snatch if I'm at all careless (depending upon how careless). This touchiness combined with a bit of driveline slop is my only complaint.

A passenger on my bike while I was shifting, might think I had an automatic transmission, it is so easy to keep speed matched to the shift without much of any shenanigans on the Red ST. I find no disruption of the bike upon shifting with no clutch slipping needed whatsoever. While I use common sense caution and avoid doing it, I would not fear the need for a mid turn downshift with the Red ST.

So far there are no steady upper RPM surges either.

STill Tom's regulator intriuges me, If you need another tester Tom I'm game, I ride daily in OK weather, though only about 60 to 80 mi. per day. I'd like to see if the throttle take up in the turns see an improvment.

For what it is worth: my driveline snatch is all that is left of abruptness in throttle roll-on. The modified fuel regulator completely eliminated my need to use a "gentle hand" on the throttle.

Marshal

[turbocity tom]

The info that I have indicates that the 05 computer has less initall timming which would lessen the jerkyness of the throttle and would tend to make them slower than the silver or blue.

[Carl_T]

OWWW! OWWW! Whip me, beat me, hurt me, :eek: your silver or blue will never be quick enough to catch it's own backside like my fine red STeed! :D She's just initially a tad smoother, but then the secret Honda factory speed tweak kicks in, and she flat out disappears into numerous other dimensions with a mere twist of the throttle. ~ :03biker: :04biker: ~~~~~~~~ :biker:

Slower..... sheese... the utter Heresy!!! :rolleyes:

[NormanPCN]

From what I understand from Turbo_Tom, the modified fuel pressure regulator does not affect horse power or torque. It just improves the way the engine copes with its delivery of fuel.

Anything that changes the amount of fuel delivered to the engine will change the horsepower and torque. For better or worse is a separate debate. Increasing the fuel pressure increases the amount of fuel delivered to engine in all circumstances.

[turbocity tom]

We are making very small changes in the total amount of fuel delivered. Remember this is a drivablity improvement. The factory has done a very good job of making max power with the stock system. I would not exspect the small changes we do to make much different in overall power. A modified ST (exhaust, K&N) may show some additional power by the slight enriching.

Tom

[hippo888]

Tom,

Do you have the figures for stock regulator PSI and the Turbocity regulator PSI?

TIA

[AZST1300A]

We are making very small changes in the total amount of fuel delivered. Remember this is a drivablity improvement. The factory has done a very good job of making max power with the stock system. I would not exspect the small changes we do to make much different in overall power. A modified ST (exhaust, K&N) may show some additional power by the slight enriching.

Tom

I'd be interested in the mod after ya'll work out the bugs, but I've tried to do some research on how many holes the injector has. I understand we have stock 6 hole type. I can't find anyone that supplies 12 hole for the ST. 12 hole would make for smoother power and more complete burn. If that is coupled with Tom's mod, it would be a complete package IMHO.

Brian

[gene]

my service manual says 50 psi for oem 2003 model

[hippo888]

re: 12 vs. 6 hole injectors.

I don't think the problem is atomization, instead, I think the problem is an overly lean mixture. The 12 hole injectors would only help if they allowed more fuel to pass than the 6 hole injectors.

I believe the some of the new CBR's use the 12 hole injectors, you could try those.

[Marshal_Mercer]

Just an update with regard to fuel economy and TurboCity_Tom's modified fuel regulator:

I just got back from a ride and thought that you would be interested in the results. All readings are from my GPS or calculated using US gallons.

Observed speed: 65-75 MPH
Average speed 63 MPH
277.7 mile, freeway drive
Fuel consumed: 5.727 gallons
MPG: 48.5

My worst fuel mileage was obtained earlier in the week: 40.2 MPG after riding 153.5 miles of canyons and city streets.

Marshal

[Putt]

To get a true difference in the fuel economy of the bike, you would have to do
a "before and after" test... Same route, same speeds etc...

Putt..

[Marshal_Mercer]

To get a true difference in the fuel economy of the bike, you would have to do
a "before and after" test... Same route, same speeds etc...

Putt..

Putt:

Done. I have kept a log of before and after.

Same route. More or less the same number of miles traveled. More or less the same traffic density. More or less the same speed. Later in the day for stock run at a slightly warmer temp. More in-town riding when stock. 47 MPG calculated by the same method but with a standard pressure (50 PSIG) fuel regulator. 48.5 MPG with mod.

That is a 3.2% decrease in fuel use when modified. I do not have enough data to calculate a t-test nor the standard error of the estimate but as a "ballpark guess", I would say that fuel use over time, pre- and post-modification, should lie significantly about the mean for "N" cases. Having improved the general feel and flexibility of the engine, reduced perceived hesitation to zero at any RPM used, and not damaged fuel economy is good news in my book. As always: your milage may vary (pun intended).

I think that your trying my bike would be a treat; the thing runs great. If you live in SoCal or will be within a few hundred miles of there, email me. We'll get together.

Marshal
mhmercer@earthlink.net

[Putt]

Thanks Marshal,

I didn't see the comparison in your original post... Keep on keeping records,
it will be interesting to see the results after an "extended" (3-4 mnth?) period
of time... I have heard about the "flat spots" in the power curve, but never have seen them in my bike, but I am interested in seeing how the increased fuel pressure works in the long run..

Thanks for the info...

Putt...

[Marshal_Mercer]

Thanks Marshal,

I didn't see the comparison in your original post... Keep on keeping records,
it will be interesting to see the results after an "extended" (3-4 mnth?) period
of time... I have heard about the "flat spots" in the power curve, but never have seen them in my bike, but I am interested in seeing how the increased fuel pressure works in the long run..

Thanks for the info...

Putt...

Hi, Putt:

Love your sig, BTW.

I did not go into a lot of detail in my original post -- mostly because I don't have as much data as I would like. Presently I'm doing a "seat of the pants" eval for TurboCity_Tom. I keep records of this sort of thing because I can't remember worth a darn if I don't.

The "flat spots" seemed to come and go on my bike. They seemed to be related to the type of fuel I used. I still don't have hard evidence for this, though. At around 2,200 RPM and again between 3,400 and 3,800 RPM there seemed to be lean spots. Up until the fuel pressure mod the latter was noticed after holding the engine in that range for several minutes. I tried to ride above or below that range to avoid it. Accelerating through it also worked. Now both spots are gone.

I have my idle speed set at 750 RPM instead of the 1,100 from stock. Not quite as smooth as at the higher speed, but close. Accelerates much more cleanly than stock without reving the engine or slipping the clutch excesively. I was not paying attention to my gear selection today and rode off from a stop in second. No complaint. Just a strong pull. I didn't need to shift as soon, but that was about it. This was slightly uphill! Actually, I was trying to avoid getting splatted as I merged back on to the roadway after a turn-around; low clouds so thick that I could not see much of anything.

My part of the test ends at 1,000 miles. If things continue as they are, the additional miles should develop nothing new. I believe that Tom has thousands of miles on his test mule with similar results to mine.

Marshal

[gene]

Guys I didn't notice any flat spots or real issues until wife went with me on 100 mile ride. 2 up bike seems lean with no snap. Has anyone tried mod and rode with passanger. Bike really really has issues riding 2-up. Would regulator be set to higher pressure if bike was rode 2-up. Strangly gas milage went up with wife on back,I must have been going slower than usual

[hippo888]

I have my idle speed set at 750 RPM instead of the 1,100 from stock. Marshal

If idle is supposed to be 1100 RPM and you're running 750 RPM, you may not be getting sufficient oil pressure to the top end. Since I don't have my bike or my shop manual, I don't know what the recommened idle RPM should be. But it you're running ~30% below recommended RPM, you may run into oil pressure issues.

The Harley guys burn up engines doing this all the time. They turn down their idle so they get that loping idle noise. Unfortunately, with the idle down that low, they don't get proper lubrication.

[Marshal_Mercer]

If idle is supposed to be 1100 RPM and you're running 750 RPM, you may not be getting sufficient oil pressure to the top end. Since I don't have my bike or my shop manual, I don't know what the recommened idle RPM should be. But it you're running ~30% below recommended RPM, you may run into oil pressure issues.

The Harley guys burn up engines doing this all the time. They turn down their idle so they get that loping idle noise. Unfortunately, with the idle down that low, they don't get proper lubrication.

Good point, hippo888. I'll check to see if that could be a problem.

Marshal

[turbocity tom]

Guys I didn't notice any flat spots or real issues until wife went with me on 100 mile ride. 2 up bike seems lean with no snap. Has anyone tried mod and rode with passanger. Bike really really has issues riding 2-up. Would regulator be set to higher pressure if bike was rode 2-up. Strangly gas milage went up with wife on back,I must have been going slower than usual
Gene,
Three weeks ago, I did a Death valley run 2 up. 780 miles total in 2 days. The drivablity was prefect.
I originally worked on this modification because of the pinging on my ST. Again this is a drivablity improvement. I too thought that my ST drove very good untill the modification was done. I had conditioned myself to drive around the hesitations and flat spots. Once they were gone a whole new ride appeared. That is why i decided to develope it further for the rest of the ST riders out there.

Thanks Tom

[gene]

Tom how is it with a K+N filter. I put in a k+n only and it was awful had to put stock filter back in. Will regulator alow use of new filter or will it be an ebay item. Really want throttle response to equal old in-line 4 with carbs and smothness, when I had K+N in vibrations were really bad when running lean motor seems to want alot more fuel to be happy.
THANKS GENE

[turbocity tom]

Gene,
I have used mine both ways and do not see a big difference. Some of the guys say they see a big improvement. I think the air inlet path of the STock air box may be the limiting factor in intake air flow.

Thanks Tom

[NormanPCN]

I have my idle speed set at 750 RPM instead of the 1,100 from stock.

Low idle speeds are bad for the bearings due to lower oil pressure. I believe Honda say 1000rpm in the manual.

I find it interesting that the bike has a idle adjustment since it is a fully computer controlled engine. If mother Honda wants the engine to idle at 1K then the computer can idle at 1K... no need for an adjuster.

[wjbertrand]

Agree with this comment 100%. Back when I had my old 1st generation VF750F Interceptor one of the official factory fixes for the cam pitting problem this family of engines had was to raise the idle speed to better ensure good lubrication.

In addition, on some bikes (notably pre-'96 ST1100s) too low an idle speed will fail to keep the battery fully charged in slow traffic. This seemed to be much less of a problem after I did the 40A upgrade to my '93 but I could still see less than full voltage if the engine was idling too slowly, even with the later alternator installed. I don't know if this affects the ST1300 however, perhaps Honda has geared the drive to spin it a bit faster than on the 1100?

If idle is supposed to be 1100 RPM and you're running 750 RPM, you may not be getting sufficient oil pressure to the top end. Since I don't have my bike or my shop manual, I don't know what the recommened idle RPM should be. But it you're running ~30% below recommended RPM, you may run into oil pressure issues.

The Harley guys burn up engines doing this all the time. They turn down their idle so they get that loping idle noise. Unfortunately, with the idle down that low, they don't get proper lubrication.

[Actionfigurejoe]

Tom, could regular gasoline be used with the high pressure regulator or would the faster rate of burn using a lower octane fuel negate the regulator's benefits?

[turbocity tom]

I think premium fuel is all that should be used in the ST. Some of the testers are reporting an increase in preformance that I think is due to the supression of the detonation that occurs with the high compression.

Tom

[hippo888]

I find it interesting that the bike has a idle adjustment since it is a fully computer controlled engine. If mother Honda wants the engine to idle at 1K then the computer can idle at 1K... no need for an adjuster.

The ST1300 runs a pretty primitive EFI system. For example, cold-start fast-idle is handled by a device that depends on wax melting to determine idle speed. It's about as primitive as you can get.

I don't remember if the ST13 can sense incoming air mass/volume either. I really need to get my shop manual...

[hippo888]

The info that I have indicates that the 05 computer has less initall timming which would lessen the jerkyness of the throttle and would tend to make them slower than the silver or blue.


Can the 05 EFI computer be retrofitted to an 03 or 04 without problems?

[turbocity tom]

Paul,
You are right, the Honda system is equal to the systems used in the late 80's-early 90's in the automotive field. The computer does not measure air flow ,only load.
The computer does not have any control of the idle speed. I believe the 05 computer can be used in the earlier ST, but it might be easier just to swap the programs. I need to look into more of how to hack the Honda computer.

[Actionfigurejoe]

I'll assume that Honda could've improved drivability AND allowed for the use of regular gas if they would've simply lowered compression a smidge. The ultra lean calibrations were probably necessary to lower NOX for the "08 CARB standards with the higher compression head. True, the hp would've dropped. Probably no more than richening the fuel curve as this device does.

[hippo888]

Tom,

All of the Japanese bikes that I've run across have CPUs that are sealed units. There are no provisions for revisions in software without complete replacement of hardware.

DynoJet has had problems getting their Power Commander III to work with the ST1300's EFI system. The Techlusion unit which only affects timed-injection seems to work better.

I'm very interested in knowing what you find out. Someone with your experience and skill set is a very valuable asset to the ST13 community.

[NormanPCN]

The ST1300 runs a pretty primitive EFI system. For example, cold-start fast-idle is handled by a device that depends on wax melting to determine idle speed. It's about as primitive as you can get.

I don't remember if the ST13 can sense incoming air mass/volume either. I really need to get my shop manual...

Primitive or not the engine needs a crank sensor to do ignition and injection. With such a sensor you know exact RPM and thus the computer can idle at whatever speed it is programmed to by adjusting its available parameters. It seems Honda programmed in a set fuel amount for idle and gave us a +- range adjustor on the preprogrammed level.

Actually your description of the fast idle circuit sensor seems like a pretty simple solution to a problem. Nothing wrong with a sensor that uses a state change (solid-> liquid) verses some resistive or other sensor type.

[turbocity tom]

Norman,
you are reading way too much into what this computer can do. It is a very simple system and has no control over the idle speed.

Tom

[Actionfigurejoe]

The ST may have no no mechanical means to adjust idle speed, but altering F/A mixture and timing will change idle speed. When the ambient temp is 35F-45F my ST will idle at 2K rpm until warm up. Then it drops nicely down to 1100 rpm. Primitive or not, it gets the job done and has proven itself to be very reliable.

[turbocity tom]

The cold start idle speed is controlled by the se thermal valve. The is mechanically connected to the starter valve that open to allow more air. They are totally dependent on coolant temperature. The computer is not controlling anything to do with the idle speed. Changes in timming and fuel delievery can effect idle speed, but not in this case.

[Actionfigurejoe]

I thought allowing more air does change the F/A mixture? :)

[turbocity tom]

The computer uses RPM,TPS,coolant temp,Map sensors then goes to a look-up table to find the proper timing offset and injector pulse width for those conditions. It is purely a calculation. After warm up the computer uses additional input from the O2 sensor to help with the calculations.
With the fuel pressure modification we are bumping all the fuel related tables and their corrections up by a very small amount. Thats how the drivablity is increased without disturbing what the computer wants to see and do.

[VNEKO]

Last Saturday, I became another "test subject" for the regulator modification.
(Thank you Tom)

------------on an 04 St, 16Kmiles, K&N

I have a few hundred miles since the "mod" and experienced the following:

-Virtually all "high load (low vacuum) pinging" has been eliminated. Pinging seems to be worse with hot weather. We had hot weather since Saturday; I rode much of the "test miles" in 90 degree OAT.

-I noticed a significant improvement in "high load" hard acceleration response, both from low and mid RPM. Not that it ever felt bad before, it just felt stronger and smoother. I believe the bike is faster, but a WOT Dyno run will not likely identify the improvement; it's a throttle roll-on improvement.

At the time of installation, I tested CO with my "cheapy" EGA. Before was 1.5, after was 3.5, both at idle and a few thousand RPM (cool-cold motor). I've used the EGA to tune many carb'd bikes and usually "target" 3.5. I've found that if I improve (richen) AFR on factory bikes, I can then run more timing to achieve what I think the makers intended, before emmissions "re-tuning".

I plan to keep re-testing CO to see if the closed loop system attempts a "benefit-negating ECU adjustment", but I doubt it. I'm aware that the cat converter and possibly o2 sensor can cause different readinngs once "warmed up".

Forgive me for being so bold as new forum guy, however, I'm speculating the o2 sensor loop will not decrease injector pulse width (to offset the higher sensed AFR) within the change in CO/AFR I observed. I think the o2 loop (like the knock sensor) would decrease timing advance (under too lean conditions)to protect the motor, leaving a small AFR "rich-overage" to be cleaned up by the cat converter.

If true, it would explain a performance difference I experienced that's hard to attribute to just a change in AFR; it feels like the motor is also benefiting from better ignition timing. It feels like other bikes that I've un-corked and re-tuned jetting and timing.

Notwithstanding and humbly accepting any deficiencies in my technical acumen, I like it. This modification has been tried with good results on other bikes/cars. I think the key point is a modest pressure increase that inhibits ECU reactions and bad effects.

p.s. I'm checking mileage, but I'll gladly forfeit a few mpg for better performance...

IMHO

Jim

[NormanPCN]

Norman,
you are reading way too much into what this computer can do. It is a very simple system and has no control over the idle speed.

Tom

Duh... I never said it could or should. My original comment was that I thought it was interesting that the computer did not given that it has all the sensors it needs to do so. Obviously Honda decided to do a simple lookup table, one way calculation setup. Given that the compute power to run a feedback loop costsa pennies these days it is interesting they bypassed that feature. Heck, riders might be pissed if they could not adjust/tweak/play with their idle.

[hippo888]

I went down to the Honda shop and had the parts guy look up the EFI computers. He said that the computers are identical for '03, '04, '05 model years. That means there's no plug-n-play way to improve the on/off throttle abruptness (if the parts guy is right). Even if the computers were different, the $1,045.00 price is prohibitive.

Would this mean that the ignition timing has been changed mechanically instead of through software? Anyone have an '05 shop manual?

The fuel pressure regulator looks more and more interesting...

[hippo888]

Jim,

What EGA tester are you using? I've always wanted to get one, but they're sooo expensive!

[dond]

[QUOTE=hippo888]The ST1300 runs a pretty primitive EFI system. For example, cold-start fast-idle is handled by a device that depends on wax melting to determine idle speed. It's about as primitive as you can get.
~~~~~~~~~~~~~~~~~~
Yes, the faST idle wax unit works juST like a coolant thermoSTat. Some things juST work :-)

[Carl_T]

The 05 manual says "new" 8 degrees before top dead center at idle.

[VNEKO]

Paul,

here's a link for the Gunson EGA. I'd recommend springing for $259 unit; not that the tach is that useful, it's just has a more robust case:

http://www.aep.bigstep.com/

more speculation.... like most bike ECU/Ignition systems, I thought our primary input (1d) is RPM (crank sensor); secondary is load (2d,map sensor) with firmware "looking up" a map table "retarded advance" value; with "override" retard values for temp, o2 and knock sensors (3d). But if the o2 sensor in our closed loop permits more advance when sensing richer AFR (despite or altering map sensor "seeing" load/retarding), then what I'm experiencing could be explained??? Or not.

Tom knows a lot more about "mapping".

This is a very subjective experience, but I've ridden the same "line" on an uphill curvy "S" turn to my house hundreds of times. I know it's hard to replicate all the variables, but what I experienced was enough difference in power delivery to cause my bike to "stand up" mid-turn and throw me off my line. The difference was much more than the difference I've felt riding with a cool motor and cool OAT.

Jim

[hippo888]

Jim,

more speculation.... like most bike ECU/Ignition systems, I thought our primary input (1d) is RPM (crank sensor); secondary is load (2d,map sensor) with firmware "looking up" a map table "retarded advance" value; with "override" retard values for temp, o2 and knock sensors (3d). But if the o2 sensor in our closed loop permits more advance when sensing richer AFR (despite or altering map sensor "seeing" load/retarding), then what I'm experiencing could be explained??? Or not.

I don't know much about EFI. But should the 2D be throttle-position-sensor instead of MAP sensor for the load input? In anycase, I don't know enough about EFI to make even an uniformed guess. What sucks is that a well tuned set of carbs has better throttle response than the stock ST1300 EFI.


This is a very subjective experience, but I've ridden the same "line" on an uphill curvy "S" turn to my house hundreds of times. I know it's hard to replicate all the variables, but what I experienced was enough difference in power delivery to cause my bike to "stand up" mid-turn and throw me off my line. The difference was much more than the difference I've felt riding with a cool motor and cool OAT.
Jim

I know what you are saying. The stock EFI is horrible because of its on/off throttle abruptness. I'd like to ride a 2005 bike and see if the retarded ignition helps any. If the ignition retard is not in software, it must be a difference in the crank angle sender.

--------------------

Tom,

I've looked up reviews of your products and your company seems well respected in the automotive market. I just wanted to respectfully ask about the life span of your fuel pressure regulator. Do you manufacture the unit yourself or is it a modified OEM Honda regulator? Will it last as long as the stock unit?

TIA

[turbocity tom]

Paul,
It is a modified Honda part. The way that it is modified should not decrease the reliablity at all. We have done this type of modification on many different regulators sense the late 1980's.
Thanks Tom

[VNEKO]

Whoops, forgot about the TPS.

Many bikes I've seen rely completely on the TPS for load with no MAP input.

I'm guessing the MAP and TPS are "viewed" together to sense load.

I have this "vision" of Tom sitting back at his desk and chuckling over my wanna-be cyco-technical babble, so I'll shut up now...

Jim

[turbocity tom]

Most systems use RPM and Map as the main controls. Basic fuel curves are deturmined from those two factors. All the other inputs TPS,O2,Coolant,Knock all provide modification to the main table. If I could figure out how to post some typical tables, It might help you understand how these work.

Tom

[turbocity tom]

Thanks to my assistant Leslie, here are some typical tables.
One is a direct data dump- it will make no sense.
The other two are descrambled base timming and base fuel tables.
These are NOT Honda tables, but are examples of the systems used.

Tom

[gene]

Tom on your web site it says regulator is adjustable for intake exhaust mods .Is this done before you ship based on bike or customor done after install.Would prefer not taking bike apart more than once. I have a K+N filter now that was removed after install because of poor drivability with it in really bad with 2-up .Ilive in MD temps run from 50-90 degrees most days through summer and alltitudes up to 2000 feet above sea level in my area. THANKS

[gene]

Tom in last post I forgot to mention bike is a 2003 with 3200 miles THANKS

[Marshal_Mercer]

I had an interesting revelation during a ride last night. At the suggestion of some respondents to this thread, I raised my idle speed to 1K RPM, then took a mountain ride. On acceleration my gear shifting was not as smooth, nor was it as smooth during deceleration. One might call the lack of smoothness “abrupt” throttle response; jerky. Taking my idle down to about 900 RPM reduced this substantially but did not eliminate it.

No abruptness was noticed when my idle was, previously, set to 750 RPM. Was oil-flow reduced to the point of harm at 750 rpm? Still do not know. Perhaps TurboCity_Tom could chime in here.

Have a great ride this weekend!

Marshal

[rob.uk]

My new "Turbocity" fuel regulator arrived Wednesday morning (thanks for prompt service and good packaging, Tom). It is a modified Honda fuel regulator, and for those worried about warranty, no-one would be able to tell the difference visually, although obviously Tom has increased the fuel pressure.

How easy was it to fit?

Tom's instructions for fitting (posted on Turbocity's web site) were very good, and I had my ST1300 running again after 2 hours work. A strongly magnetized cross head screwdriver was very helpful to make sure I did not drop the airbox screws down the side of the engine. I marked each of the 90 degree air intake tubes with "Tipp-ex" before disconnecting them, so I could be sure to replace each of them where it came from. Also it helped to remove the fuel tube from the fuel pump before disconnecting the other end from the original fuel regulator - this gave some slack which was necessary when rotating the regulator to get a pair of pliers onto the spring clamp to release the hose that end.

So, what's the verdict ?

(based on first 150 miles since fitting the new regulator)

Firstly I now have a smoother idle at about 900rpm, and the engine pulls more evenly while changing up through the box. There seems to be more low down torque, and starting from standstill in second and third gear is no longer an embarassment.

I would be very interested in seeing torque measurements from a dyno before and after fitting Tom's regulator. It "feels" like there is a big increase in low down torque, and it would be great if someone has the facilities to measure and confirm this.

Whereas with the stock regulator, my ST1300 would "surge" when accelerating/ decelerating between 3500 rpm and 5000 rpm, there is now no surging at any rpm range.

The one thing it is unreasonable to expect the new regulator to fix is the shaft drive backlash if you are not steady on the throttle when accelerating/ decelerating in first gear. However, the engine is smoother at low rpm, so the problem is less apparent than with the stock regulator. I find it is still better to apply small amounts of rear brake to control speed in slow traffic, maintaining constant throttle. This avoids any shaft drive backlash.

I'm looking forward to my touring holiday in France end May/ first week June, when I will be doing at least 1,000 miles, so I expect to be able to provide a longer term report soon.

Meanwhile if anyone has any questions that I might be able to answer in the week before I leave, I'll be glad to help.

Best regards,
Rob
:cbcgw1:

[AZST1300A]

Tom...
I'm in Phoenix and am interested in the mod, and willing to be a test bike (when I get it back). Do you have a shop that can install it? I'm not unknowledgable when it comes to wrenchin, but would rather trust your experience in this area.

I'll send my phone number in a e-mail.

[AZST1300A]

Next week we are to do some tailpipe emission testing. I will post the results.
I suspect that there will be a very small increase, but should not pose a problem to any state retest (does any state require testing on a bike?)

Thanks for everyones input and support. Tom

Arizona retests bikes...

[Marshal_Mercer]

Hi, all.

More follow-up on the fuel mileage and general ridability questions: rode to Solvang, CA again yesterday; third trip. Although the freeway seemed more like a parking lot than the last two times, and the temp varied from 68 to 98 degrees F. where it had been in the 70s before, my bike continued to run flawlessly! Same great off-idle response, no 3.5K to 4.0K RPM hesitation. I actually cruised for a quarter mile, or so, at slightly off idle speed: 1,200 RPM. No complaint. Throttle response was sluggish at that RPM but there was no hesitation noticed.

Even with the vastly increased traffic, gas mileage was up; 48.5 MPG last trip, 49.2 MPG this trip. 80+ miles of mountain riding dropped the gas economy to 40.2 MPG. All trials were recorded as seperate trips on my GPS and bike Odometer, and gas receipts were used to record fuel to fill. My mountain trip produced the closest actual versus bike-meter MPG: 39.4 versus 40.2 actual.

At 726.6 miles in this test I am VERY pleased. One problem, though: my face is becoming contorted from all of the smiling. ;)

Enjoy,

Marshal

[turbocity tom]

Tom on your web site it says regulator is adjustable for intake exhaust mods .Is this done before you ship based on bike or customor done after install.Would prefer not taking bike apart more than once. I have a K+N filter now that was removed after install because of poor drivability with it in really bad with 2-up .Ilive in MD temps run from 50-90 degrees most days through summer and alltitudes up to 2000 feet above sea level in my area. THANKS
Gene.
I can custom set the fuel pressure at the time of install. With a k&N filter I would set the pressure just a little higher.
Thanks Tom

[turbocity tom]

Tom...
I'm in Phoenix and am interested in the mod, and willing to be a test bike (when I get it back). Do you have a shop that can install it? I'm not unknowledgable when it comes to wrenchin, but would rather trust your experience in this area.

I'll send my phone number in a e-mail.
Brian,
If you wanted to come to my shop, we could do an install for you.
Do you know how the retest is done?
When does your ST come up for retest?
I would like to see how the modified regulator runs thru the test.
Thanks Tom

[turbocity tom]

I had an interesting revelation during a ride last night. At the suggestion of some respondents to this thread, I raised my idle speed to 1K RPM, then took a mountain ride. On acceleration my gear shifting was not as smooth, nor was it as smooth during deceleration. One might call the lack of smoothness “abrupt” throttle response; jerky. Taking my idle down to about 900 RPM reduced this substantially but did not eliminate it.

No abruptness was noticed when my idle was, previously, set to 750 RPM. Was oil-flow reduced to the point of harm at 750 rpm? Still do not know. Perhaps TurboCity_Tom could chime in here.

Have a great ride this weekend!

Marshal
Marshal,
I talked to my service rep at Honda about the oil pressure at 750 rpm idle. He indicated that there should be no problem at the lower rpm and that he has seen oil flow to the topend while cranking.
Sorry in the delay on these questions, but I was enjoying my ST. Went up he coast Thursday evening and returned yeasterday Sunday. Great ride, two up and fully loaded the bike ran great.

Thanks Tom

[Marshal_Mercer]

Marshal,
I talked to my service rep at Honda about the oil pressure at 750 rpm idle. He indicated that there should be no problem at the lower rpm and that he has seen oil flow to the topend while cranking.
Sorry in the delay on these questions, but I was enjoying my ST. Went up he coast Thursday evening and returned yeasterday Sunday. Great ride, two up and fully loaded the bike ran great.

Thanks Tom

Thanks, Tom:

I really had no doubt that there would be sufficient oil flow at that engine speed. Thought that it should be discussed, though.

Glad that you had such a good trip. Went to the Solvang Motorcycle Museum on Saturday myself. Clear air was great if not a tad on the hot side coming back in to town.

Marshal

[Carl_T]

Tom, have you tried one on an '05 yet with the retarded idle? Just wondering if the improvement is smaller to none, since I have only bare hints of issues others have been complaining about.

[turbocity tom]

Tom, have you tried one on an '05 yet with the retarded idle? Just wondering if the improvement is smaller to none, since I have only bare hints of issues others have been complaining about.
Carl,
Most of the 05's testers have very few miles on them. Just broken in. I would like to try one on an 05 if someone wants to.
Thanks Tom

It could also be that the bike is new to you and the drivablity issues might take a while for you to see them. As I've said before, I thought mine drove very good untill I made the modification which then I noticed more of what the problems had been. I had learned to drive around the issues.

[wjbertrand]

Carl,
Most of the 05's testers have very few miles on them. Just broken in. I would like to try one on an 05 if someone wants to.
Thanks Tom

It could also be that the bike is new to you and the drivablity issues might take a while for you to see them. As I've said before, I thought mine drove very good untill I made the modification which then I noticed more of what the problems had been. I had learned to drive around the issues.

I'd like to try one in my '05. Do you still need testers? I do about 500 miles/week.

[Actionfigurejoe]

Tom, I'm a little skeptical. Not sure if the regulator will improve driveabilty on the "05. I'd be willing to give it a try though.

[Carl_T]

Same here Tom, I’d love to give it testing. I ride at least a minimum amount daily weather permitting, mostly over winding roads that run the revs between 4 and 7 thou through the turns, 2800 to 4000 on steady straights connecting turning areas, various gears. While I don't have issues with flat spots, I do definitely ride around throttle take up (finger braced on the front brake for finesse) in turns and consider anything below 3000 to be only coasting between times of the engine having to do anything, as it's pull is quite anemic there. The 05 I have pulls smoothly from 3000 on up, but throttle take up continues to be a touchy (but manageable) animal.

Weekends involve some two up riding on more open roads. June 3rd will see the wife and I spending a 3 day weekend get together with other ST owners in the North East, spending long days riding a wide variety of roads also.

The bike is pretty well broken in and I know it's quirks well enough now to be able to have a feel for subtle and not so subtle changes.

[John Mintz]

Yes, interested. 2004 ST w/4500 miles so far. Put 6000-10000 mi. per year on the bike, mostly day trips and a few long rides 500-750 mi.

JM

[AZST1300A]

Brian,
If you wanted to come to my shop, we could do an install for you.
Do you know how the retest is done?
When does your ST come up for retest?
I would like to see how the modified regulator runs thru the test.
Thanks Tom

AZ requires an emmisions test for all vehicle older than five years, down to around 1967. The bike won't be required til the fall of '07.

I thought it was sooner, but that info is according to ADOT's site.

When I get to the point of getting the MOD, I'll have my shop here do sniff test before and after, just to see the difference.

[hippo888]

From the June 2005 issue of Sport Rider:

"Some common points all three bikes [ST1300, ZZR1200, FJR1300] share: Throttle response is atrocious, with a sudden lurch of power from closed throttle; throw in excessive driveline lash (especially on the Honda) and it is almost pointless to try and carry momentum in corners... And all three will roast your calves in even moderate temperatures."

[Carl_T]

The driveline lash is mildly annoying most of the time, occasionally just plain out annoying. I have no problem carrying momentum through turns at all, though the throttle is touchy it can be finessed, perhaps it's the timing change on the 05. I also have no heat issues and my calves sing a happy tune, though about 86 is as high a temp as I've ridden in so far and I do have the fairing extensions on. When it goes up to 100 then we'll see.

[gene]

Tom has testing been done on any 2003 bikes, all posts seem to be 2004 models . Are 03 and 04 models identical efi and timing wise . 05 seems to be different according to some posts. THANKS

[crazykz]

The driveline lash is mildly annoying most of the time, occasionally just plain out annoying. I have no problem carrying momentum through turns at all, though the throttle is touchy it can be finessed, perhaps it's the timing change on the 05. I also have no heat issues and my calves sing a happy tune, though about 86 is as high a temp as I've ridden in so far and I do have the fairing extensions on. When it goes up to 100 then we'll see.

There was a timing change on the '05's???? Can it be applied to the earlier models?

Curt

[turbocity tom]

Tom has testing been done on any 2003 bikes, all posts seem to be 2004 models . Are 03 and 04 models identical efi and timing wise . 05 seems to be different according to some posts. THANKS
Gene,
We are currently testing all years and geographic locations. We should conclude testing in about 2-3 weeks.

Thanks Tom

[Marshal_Mercer]

Gene,
We are currently testing all years and geographic locations. We should conclude testing in about 2-3 weeks.

Thanks Tom
Speaking of testing -- my 1,000 miles will be completed this week-end; had to part-out tires this week.

The best thing about the fuel pressure regulator is that is makes my ST1300 accelerate and cruise easily and smoothly, as it should have done in the first place. Fuel use is about the same as before.

There is no worst thing. Nor an almost bad thing.

I recommend this mod without exception. Try it, you'll like it.

Marshal

PS Tom: I don't have your email address. Could you send it to me?
mhmercer@earthlink.net

[gene]

Thanks Tom , when testing is done could you post outcome. I will wait till testing is complete to purchase unit .Looking forward to smooth operation.

[Dketchum]

I too am interested in purchasing a unit for my 2003. But want to wait for the testing to be completed and results documented.

I suspect the outcome will be positive :o:

[Ken]

I'm currently on my third tank of gas with the new regulator, with a mix of commuting and touring miles. I have found the installation to be painless (about 40 minutes), acceleration is much smoother, 4th gear is happier at low speeds, change in MPG is negligible - still getting btween 40-50 depending on ride aggressiveness and commuter roads versus touring roads. I also had a chance to do some 2-up and found it to be fine. The 'dead' spot in the 3800-4000 RPM is no longer. IMO, there are no adverse effects and plenty of positive effetcs. Thank you Tom for allowing me to be a part of the test. I will be sending back the stock regulator next week. All I ask is that if you make changes/modifications/improvements of any sort to the regulator that we be notified and allowed to upgrade. Thanks!

[hippo888]

Tom,

Thanks for answering my questions on the phone -- I forgot to ask some and thought this would be a convenient place to ask.

Have you had a chance to test the effects of the fuel pressure regulator at differing loads and RPMs? My Harley is set up to run lean at idle and cruise, but goes to 13.x:1 WOT. Is the ST13 set up lean throughout its load/RPM map? If the ST13 is set up to run rich WOT, then the increased fuel pressure will make everything too rich at WOT?

I was just doing some calculations... If you can consider a linear increase in fuel pressure to be a linear increase in fuel delivery, then the 16% increase (50psi to 58psi) would take an economy maximizing AFR of 15.x:1 to 13.x:1 which would be a power maximizing AFR? (You had mentioned that the AFR was set at 15.x:1 stock and 14.x:1 with your regulator, but I forgot to ask where in the RPM/load range).

If I want to take AFR readings, do you recommend Riv-Nuts in the headers or should I get someone to weld stainless steel nuts to the headers?

Do you see any problems with the catalytic converters getting fouled by excessive soot or is the modified AFR well below the point where we have to worry about that?

I'm eagerly awaiting your fuel regulator!

[Marshal_Mercer]

I have 1,111 GPS miles completed since TurboCity_Tom installed his 58 PSIG fuel-pressure regulator on my 2004 ST1300 ABS.

This is what I said on Tom's web-site by way of reviewing his product:
"I have ridden over 1,000 miles since the Turbo City fuel pressure regulator was installed on my 2004 Honda ST1300 ABS. This is what I have noticed: smoother running; at least the same level of acceleration as before installation -- perhaps a bit more; fuel milage very slightly less than before (0-2 MPG); no negative influences on the bike's other systems.

The best thing about the regulator is that is makes my ST1300 accelerate and cruise easily and smoothly, as it should have done in the first place. There are no "flat" spots or hesitations when cruising between 2,200-2,400 RPM, and again between 3,600 and 3,800 RPM. Rolling-on the throttle makes haste; not fuss. Vibration, never a concern before, is virtually absent now. Fuel use is about the same as before at between 40-50 (GPS measured) MPG, depending on my type of riding.

There is no worst thing. Nor is there an almost bad thing.

I highly recommend this modification without exception. Try it, you'll like it."

I kept an Excel spreadsheet of the steps through the test. If Tom wishes to make this public, I'll be hapy to comply.

This is the end-of-the-line for my part of the test. I'd like to thank Tom for making this modification possible. GO TOM!

Marshal

[wjbertrand]

I just finished installing my unit, thanks Tom, impressions to be gathered over the next couple/few weeks. The installation was uncomplicated, but it would be better to do it with the top tank completely empty as I had to stick the old regulator back on, to keep from spilling gas everywhere and go looking around my garage for something to plug the hose with before I could remove it. I found that I could re-connect the (air temp?) sensor in the lid of the air box with the lid hanging over the left side of the bike, out of the way, for the leak test to avoid having to remove the sensor from the lid or cause an error code to be set by starting the bike with it unplugged.

As A bonus I found the missing "hat" washer from the left front fuel tank bolt hole, down underneath the TBs on the rubber mat. I guess I must have dropped it down there after my last farkling session.

[rob.uk]

I just returned from touring France, my St1300 (02 model) with Turbocity Tom's new regulator fitted. I did 1600 miles during the week, 2-up with my daughter riding pillion, and with panniers and top box full. I agree all the reports from Marshall and others - the new regulator eliminates flat spots above 2000 rpm, results in smoother acceleration, and has negligible effect on fuel economy. It also seems to me that torque at low RPM is increased, but I have no way to measure this.

Regards,
Rob

[sportridervince]

I have been following this thread with some interest. I have recently purchased a 2005 ST and have ridden about 1500 kms and I am experiencing the same surging in the 3500 to 4000 range and as well in the lower 2000 to 2500 range. I live in Calgary Alberta which is at about 3400 ft elevation. Not sure if that makes a difference. In any case I am anxiously awaiting the final results of the rider tests ... certainly sounds very promising so far.

Part of the reason that I am writing this is that some other 2005 owners expressed that they were not having the same surging problems as the earlier models. Not sure why mine is different .... could be some differences between U.S. and Canadian models I suppose.

I had written Tom and he replied saying he should have all the final results tallied in the next couple of weeks. I have even heard a rumor about a group buy / discount on the regulator.

Vince Rosso
Calgary Alberta
2005 ST1300

[rob.uk]

I have been following this thread with some interest. I have recently purchased a 2005 ST and have ridden about 1500 kms and I am experiencing the same surging in the 3500 to 4000 range and as well in the lower 2000 to 2500 range. I live in Calgary Alberta which is at about 3400 ft elevation. Not sure if that makes a difference. In any case I am anxiously awaiting the final results of the rider tests ... certainly sounds very promising so far.


Vince, the St1300 with stock regulator has a tendency to run too lean on deceleration, causing surging on the transition when the mixture richens up again when you open the throttle. At higher altitudes this transition might be more pronounced, although on my '02 ST1300 I experienced surging despite living at Sea Level in East Anglia UK. I fitted Tom's regulator which increases fuel pressure slightly, and seems to prevent the lean spots during deceleration, hence gets rid of the surging at high speeds. Last week's 1500 mile test at various altitudes in France confirms this. However I still feel the grab of backlash in the shaft drive at low speed unless I keep the engine loaded by dragging the rear brake slightly while maintaining some throttle. Regards, Rob.

[hippo888]

I finally got the TurboCity fuel pressure regulator into my bike.

Some observations from a short 25 mile ride.

My idle did not change. The bike still burbles pleasantly on decel. This leads me to believe that the increased fuel pressure does not overly richen the mixture at idle (however, the PAIR valve could be causing the backfire on decel).

The TurboCity fuel pressure regulator completely changes the nature of the bike. The Honda's patented "world's worst fuel injection throttle response" feature is now gone. The throttle is no longer a light switch. It has linear response and is much, much more predictable.

My bike never surged, so I can't comment on that.

Midrange seems to be a bit stronger -- or maybe the power curve is now more linear without a dip in the EPA testing region.

My only concern is if the increased fuel pressure causes an overly rich mixture at high loads/high RPM operation. Given the lack of RPM change at idle, I don't think this is going to be a problem. Once I get a couple of hundred miles on the new regulator, I'll pull the plugs out and see how the overall mixture is doing.

I can't overstate how much of a difference the new fuel pressure regulator has made for me. There were two reasons that have made me think of selling my ST13. #1 is the heat. #2 is the horrid EFI response. The new fuel pressure regulator solved #2 (and I think with the board's help I've got #1 under control). Maybe if you didn't feel that the EFI was bad in stock form you won't feel much difference with the TurboCity regulator, but I'm really, really sensitive to throttle control and the new regulator has completely changed my opinion of the ST13.

[Carl_T]

Glad to hear the feedback guys. I went in on the group buy now in progress in the "news" section.

If throttle take up is improved on the '05 model, I will be in ecstasy.

[wjbertrand]

I finally got the TurboCity fuel pressure regulator into my bike.

Some observations from a short 25 mile ride.

My idle did not change. The bike still burbles pleasantly on decel. This leads me to believe that the increased fuel pressure does not overly richen the mixture at idle (however, the PAIR valve could be causing the backfire on decel).

The TurboCity fuel pressure regulator completely changes the nature of the bike. The Honda's patented "world's worst fuel injection throttle response" feature is now gone. The throttle is no longer a light switch. It has linear response and is much, much more predictable.

My bike never surged, so I can't comment on that.

Midrange seems to be a bit stronger -- or maybe the power curve is now more linear without a dip in the EPA testing region.

My only concern is if the increased fuel pressure causes an overly rich mixture at high loads/high RPM operation. Given the lack of RPM change at idle, I don't think this is going to be a problem. Once I get a couple of hundred miles on the new regulator, I'll pull the plugs out and see how the overall mixture is doing.

I can't overstate how much of a difference the new fuel pressure regulator has made for me. There were two reasons that have made me think of selling my ST13. #1 is the heat. #2 is the horrid EFI response. The new fuel pressure regulator solved #2 (and I think with the board's help I've got #1 under control). Maybe if you didn't feel that the EFI was bad in stock form you won't feel much difference with the TurboCity regulator, but I'm really, really sensitive to throttle control and the new regulator has completely changed my opinion of the ST13.

I've got a few hundred miles on my '05 since installation and I would agree that the throttle on/off transistions seem smoother and the flat spots/hesitations also appear to be reduced in the 3-4K RPM range. I'd stop short of saying it's dramatically better but then my '05 seemed to be better in this regard than the '03 press bikes I rode for MCN a couple years ago to start with. Bike-to-bike variations or perhaps Honda has quietly made some improvements to the '05? OK, so I'm maybe over-compensating for the placebo effect, but I'm trying to be critical here.

So far I have noticed absolutely no effect on gas mileage, but I've only run a tank and half through. Tomorrow I'm going to be doing some twisties, so this should be a good test of the throttle abruptness issue. Upon initial installation and start up the first thing I noticed in my case was a slightly elevated idle speed, particularly when the engine is cold. I backed it off a smidge to 1000 RPM where it was before. No downsides noted as yet.

[Marshal_Mercer]

I finally got the TurboCity fuel pressure regulator into my bike.

Some observations from a short 25 mile ride.

My idle did not change. <snip>


My idle speed did not change either. Until I changed it, that is. (Actually, Tom changed it. I changed it upward weeks later, then changed it back to Tom's setting), My point about idle speed was that it CAN be changed to a much lower speed; 750 RPM in my case, without a loss of "drivability". I also found that shifting up or down is much smoother at 750 than at 1,000 RPM. YMMV.

Needless to say: I am a strong booster of this mod. :bow1:

Marshal

[hippo888]

I've got a few hundred miles on my '05 since installation and I would agree that the throttle on/off transistions seem smoother and the flat spots/hesitations also appear to be reduced in the 3-4K RPM range. I'd stop short of saying it's dramatically better but then my '05 seemed to be better in this regard than the '03 press bikes I rode for MCN a couple years ago to start with. Bike-to-bike variations or perhaps Honda has quietly made some improvements to the '05? OK, so I'm maybe over-compensating for the placebo effect, but I'm trying to be critical here.


The '05 bikes have less ignition advance than the '04 or '03 bikes. This would help with the on/off throttle abruptness.

[rob.uk]

The '05 bikes have less ignition advance than the '04 or '03 bikes. This would help with the on/off throttle abruptness.

Can anyone advise on how the ignition advance is adjusted? Thanks.

[dond]

Can anyone advise on how the ignition advance is adjusted? Thanks.
The ign pulse generator is fixed and not adjuSTable. The ICM is built into the ECM. Of course, nothing's impossible. :p:

[hippo888]

I checked out the parts numbers on the 04 and 05 ECMs. They are the same. The difference is somewhere else. Maybe they just changed the tooth/teeth location on the sending wheel?

[Carl_T]

They also may have simply corrected an error in the previous manuals.

[dond]

I checked out the parts numbers on the 04 and 05 ECMs. They are the same. The difference is somewhere else. Maybe they just changed the tooth/teeth location on the sending wheel?
I tend to agree with Carl re: a correction. If they changed the pulser rotor that would affect timing across the board giving (probably) more total advance, thereby negatively affecting top end. It would tend to liven up lower rpm response tho'.
Edit to include: Sorry, I was thinking Honda had maybe put in more advance. oops

[dond]

The pn for the '03 pulser is 30291-mcs-000. Anyone have an '05 parts catalog? It's in the clutch section .

Curious:

[curmudgeon]

The pn for the '03 pulser is 30291-mcs-000. Anyone have an '05 parts catalog? It's in the clutch section .

Curious:

Same P/N Don

[curmudgeon]

I just checked the P/n of the PGM-FI and it's the same for all years. On the other had it may have an eraseable programable chip. Does anybody know if the FI unit can be reprogramed??

Phil

[Carl_T]

Leo, :crackup :crackup :crackup Man that was hilareous! Where do you think this shiznet up anyway? :crackup :) :03biker: :04biker: ~~~~ :biker:

On a serious note, I doubt Honda gives a whizzznet about our carping over throttle or flat spots, since the bike is so good overall, at least not enough to retool a whole run of parts.

[turbocity tom]

I just checked the P/n of the PGM-FI and it's the same for all years. On the other had it may have an eraseable programable chip. Does anybody know if the FI unit can be reprogramed??

Phil
The replacement computers may all have the same part number, with the updated 05 program that Honda would retro-fit into 03's-04's as a replacement. Any computer produced after a cut-off date would have the latest program to simplify replacement.

Just a guess, I'm still trying to get ahold of an 05 computer to try in my 04.

Tom

[curmudgeon]

Tom, have you or anybody else ever done an exhaust gas analysis of a 03 vs. and 04, 05?


Phil

[wjbertrand]

Well, I'm becoming more of a believer. Did some nice twisties yesterday and a blast up to 120 MPH. I am more convinced that there is indeed a real improvement in throttle abruptness with the higher pressure fuel regulator. I usually have at least one corner where I get into a little bit of an off-on-off bucking action, usually as a result of a bump and forgetting to keep a relaxed grip on the bars. None of that yesterday. It's a subtle improvement because, the bike acts more like you expect it to, so the absence or improvement doesn't shout at you. After a while you just notice, gee I haven't had any bucking moments today.

Tom can you explain exactly how the heck higher pressure in the fuel rail results in this improvement? Intuitively, I would expect that slightly more fuel is being squirted out when the injectors are opened, assuming they are open the same period of time both before and after the modification. The thing I don't understand is why don't the O2 sensors in the exhaust notice the richer mixture and back off the injector open period to bring things back in, defeating the change? If this were happening (and maybe it is?) now you have the same amount of fuel delivered but at higher pressure through a shorter duration. Is there some magic in the delivery, even if the total amount of the fuel is the same? Maybe the ECU/injectors are already "pegged" at their shortest durations and the O2 sensors and computer can't compensate any farther?

Another thought I had was that perhaps the elevated pressure is enough to cause a little leakage at the injectors when they are closing and opening, making the shut off/on more fuzzy?

Scratching head :confused:

[Putt]

Well, I'm becoming more of a believer. Did some nice twisties yesterday and a blast up to 120 MPH. I am more convinced that there is indeed a real improvement in throttle abruptness with the higher pressure fuel regulator. I usually have at least one corner where I get into a little bit of an off-on-off bucking action, usually as a result of a bump and forgetting to keep a relaxed grip on the bars. None of that yesterday. It's a subtle improvement because, the bike acts more like you expect it to, so the absence or improvement doesn't shout at you. After a while you just notice, gee I haven't had any bucking moments today.

Tom can you explain exactly how the heck higher pressure in the fuel rail results in this improvement? Intuitively, I would expect that slightly more fuel is being squirted out when the injectors are opened, assuming they are open the same period of time both before and after the modification. The thing I don't understand is why don't the O2 sensors in the exhaust notice the richer mixture and back off the injector open period to bring things back in, defeating the change? If this were happening (and maybe it is?) now you have the same amount of fuel delivered but at higher pressure through a shorter duration. Is there some magic in the delivery, even if the total amount of the fuel is the same? Maybe the ECU/injectors are already "pegged" at their shortest durations already and the O2 sensors and computer can't compensate any farther?

Another thought I had was that perhaps the elevated pressure is enough to cause a little leakage at the injectors when they are closing and opening, making the shut off/on more fuzzy?

Scratching head :confused:


Or,
With the increased pressure/shorter injector pulse spray, a finer fuel droplet
size?? I'm with you Jeff, if the ECM can compensate for the increased
fuel flow, it should back off on the injector pulse length to get the
air/fuel ratio back into the correct range..

Putt..

[turbocity tom]

The trick with these type of modifications is to stay within the limits of what the computer expects to see. The small amount that we change the pressure does not send the computer looking for a problem.

Thanks Tom

[nisbeam]

Fitted mine this morning & done about 100 miles so far. I agree this is a subtle improvement. My 04 did not have any surging problems, and I guess I must have compensated for some snatchiness at lower revs by keeping the revs up & using a lower gear, but there is a difference !!! It is possible to go up into 5th and drive at low revs that was not possible before.. I must admit that I probably wont do this much as I prefer to keep within a range where more torque would be available if needed without having to change down. But that isnt the only improvement. It is subtly smoother at higher revs also, and seems to pull more cleanly, the whole ride is just a bit more relaxed somehow. I also got a chance to try some twisties, where it was necessary to choose the right gear and drive around with a nice steady throttle, and I found this also seemed better - I deliberately eased off just a touch and there was no dramatic change, and I could just roll on the throttle again and in came the extra power. This is how the bike should have been in the first place - great mod, and thanks for the quick delivery Tom. :03biker:

[Kirby]

I'm also interested....although I don't ride long miles...I ride a lot of shorter rides....with lots of intown riding....if I qualify, I'd be interested in the Beta testing.

Kirby Martin
Dallas, Texas
kurbster@swbell.net
2003 ST1300a 11,300 miles Bone stock

[NormanPCN]

I thought the O2 sensors were only used by the ECM in a steady state limited RPM range and limited throttle range. Or to put it another way... at crusing speeds.

[clickr]

Thanks forum members: this kind of info is just what I need to make a good decision in buying a st1300.

When I buy one, the FPR will be the first mod to be put in.

[daveman]

I guess I discovered this thing too late to get in on the group buy, :( but I've got a question about it nonetheless. I don't seem to have any "abruptness" problems with the throttle, except under one specific condition. It's when I'm using the Brake-away throttle lock. Oftentimes, I am cruising at a set speed, which corresponds to, say, 3200 RPM. I will pull in the clutch and the revs rise to around 3500. I want to go a bit faster (1-2 MPH), so I open the throttle the least possible amount. But the bike wants to go 5-10 MPH faster! I pull in the clutch to see how much faster the engine wants to run, and it about redlines! The weird thing is, I don't notice this behavior when I don't use the throttle lock. I guess I'm just used to subconsciously and constantly adjusting the throttle to maintain my speed, kind of like small constant steering inputs to control your direction, I suppose.

So my question is this: will this regulator greatly improve my ability to make SMALL, precise adjustments to my crusing speed when using a throttle lock?

[04ST1300a]

So my question is this: will this regulator greatly improve my ability to make SMALL, precise adjustments to my crusing speed when using a throttle lock?

No.

. :04biker:

[Marshal_Mercer]

I guess I discovered this thing too late to get in on the group buy, :( but I've got a question about it nonetheless. I don't seem to have any "abruptness" problems with the throttle, except under one specific condition. It's when I'm using the Brake-away throttle lock. Oftentimes, I am cruising at a set speed, which corresponds to, say, 3200 RPM. I will pull in the clutch and the revs rise to around 3500. I want to go a bit faster (1-2 MPH), so I open the throttle the least possible amount. But the bike wants to go 5-10 MPH faster! I pull in the clutch to see how much faster the engine wants to run, and it about redlines! The weird thing is, I don't notice this behavior when I don't use the throttle lock. I guess I'm just used to subconsciously and constantly adjusting the throttle to maintain my speed, kind of like small constant steering inputs to control your direction, I suppose.

So my question is this: will this regulator greatly improve my ability to make SMALL, precise adjustments to my crusing speed when using a throttle lock?

Daveman:

The short answer is "no". I think that its addition is beneficial regardless of this though.

Now about your situation -- I do not experience with my BrakeAway what you describe. Out of curiosity, when your BrakeAway is locked, can you still move the throttle twist grip; you should be able to fairly easily. Not so much that the thrttle returns by itself, mind you, but easily. The problem may be that your four set-screws are adjusted in too tightly. If they are, then your effort to move the twist-grip more open or more closed may be taking too much effort, resulting in your overshooting your target.Try backing out the four screws about one-half turn each with the Allen-head wrench provided. Take a ride. Adjust more if needed. I hope that is all that you need.

Marshal

[daveman]

Out of curiosity, when your BrakeAway is locked, can you still move the throttle twist grip; you should be able to fairly easily. Not so much that the thrttle returns by itself, mind you, but easily. The problem may be that your four set-screws are adjusted in too tightly.
Marshal,
Yes, I can still move the throttle fairly easily with it locked. I'll try loosening the set screws a bit, though. Thanks!

[pdfruth]

I've burned a couple tanks of fuel, with the new FPR, now.

Mostly at high altitudes... that is between 6,000 - 14,000 feet.
Did Mt Evans one day, and Pikes Peak another.

I'd definitely say that overall drivability is noticeably improved. For me it was never really a big deal in the first place.

However, I do still notice the twitchy throttle transitions and flat spots. Seems to be more noticeable above 8000 ft. And the ST doesn't want to stay running at 14,000 ft. Have to finesse the throttle to keep it running. Perhaps my idle is set to low (1000 RPM).

Something else I noticed... my Fuel Consumption Display (FCD) now calculates avg mpg more accurately. It used to show a lower mpg than actual... say 48 mpg, when infact it was really 52.
Has anyone else noticed this?
Perhaps it's just a result of riding to high altitude (or, rather the decent, where there's lots of coasting).

My fuel milage doesn't appear to have change much. Maybe 1 mpg, if even that. I'm still getting 51-52 mpg.

[wjbertrand]

I've burned a couple tanks of fuel, with the new FPR, now.

Mostly at high altitudes... that is between 6,000 - 14,000 feet.
Did Mt Evans one day, and Pikes Peak another.

I'd definitely say that overall drivability is noticeably improved. For me it was never really a big deal in the first place.

However, I do still notice the twitchy throttle transitions and flat spots. Seems to be more noticeable above 8000 ft. And the ST doesn't want to stay running at 14,000 ft. Have to finesse the throttle to keep it running. Perhaps my idle is set to low (1000 RPM).

Something else I noticed... my Fuel Consumption Display (FCD) now calculates avg mpg more accurately. It used to show a lower mpg than actual... say 48 mpg, when infact it was really 52.
Has anyone else noticed this?
Perhaps it's just a result of riding to high altitude (or, rather the decent, where there's lots of coasting).

My fuel milage doesn't appear to have change much. Maybe 1 mpg, if even that. I'm still getting 51-52 mpg.

As far as I can figure the fuel mileage calculator is getting its information from the electronics/electricals counting fuel injector pulses, measuring distance and monitoring thottle opening, and the like (but maybe T.O. is accounted for in the injector pulse? :confused: ) The FPR change doesn't affect any of that so it should not influence the computer at all.

[CaST]

I am looking for a few more "test Subjects" for the recalibrated fuel pressure regulator that we produce. So far the test results are very favorable but we would like some more testing. The parts would be provided at no charge in exchange for some data collected. We would like to have riders that use the ST regularly and may have some feel for the changes that we can produce. We need a few more STock bikes, and maybe a modified one. If you are interested let me know.

Tom
Are you still looking for test subjects?

[John Anthony]

I installed my unit today. I'd already done a McCruise install so this was no big deal. Only have a few miles on it but idle and low end seem smoother. Will be racking up some good test miles next weekend.

[CaST]

Are you still looking for test subjects? I have an 05 with about 1200 miles on it.

Thanks,

Patrick

[VNEKO]

04 ST K&N 18.4kmiles

It's been almost 2 months since Tom installed the FPR mod, with around 2500 miles since the change.

No negative issues and observations remain the same as my last post; better roll-on power, significantly reduced pinging and I think it's running cooler (based on my recollection of cooling fan-on frequency from last summer).

And, I still suspect the richer mixture enables timing improvement or more specifically inhibits timing retard. EGA readings are about the same as the first test.

Very happy with the improvement.

Jim

[clacot]

I am looking for a few more "test Subjects" for the recalibrated fuel pressure regulator that we produce. So far the test results are very favorable but we would like some more testing. The parts would be provided at no charge in exchange for some data collected. We would like to have riders that use the ST regularly and may have some feel for the changes that we can produce. We need a few more STock bikes, and maybe a modified one. If you are interested let me know.

Tom

Hi Tom

I am interested to recalibrated my Honda ST1300 2005, already bought your new EFI but need to be recalibrated.. i am from Canada but will drive to california next summer ( June 2006) so see you soon..

clacot

[Kempo-STer]

I guess I discovered this thing too late to get in on the group buy,

Dave,
I believe Tom adjusted his prices to group buy all the time to save himslef the hastle of it.

So you will most likely pay the group buy rate...

[Kempo-STer]

Thanks forum members: this kind of info is just what I need to make a good decision in buying a st1300.

When I buy one, the FPR will be the first mod to be put in.


Clickr..Good mod and easily installed Brian (Georgeorge) and I have it down 2 a science now..
We have done 4 of them now and do it in about 20 minutes..

Look for our 'Jiffy..FPR' Store and franchise opportunities in a state near you.:p:

[uptoblackwood]

Tom,

I just bought one of your regulators and it's great. I would be glad to help. Just let me know.

Forest

[yoitsmatt!]

My 05 St Has 1200 Miles On It And I Use It As A Daily Commuter 25+ Miles Id Love To Be Considered As A Tester, I Am An Ase Certified Master Auto Tech So I Hope I Could Give Good Feedback