Do you want more power? come in.

[Catmandu2]

I was referring to the Turbo Tom lid mod? I had never heard of it and wondered why it feel out of favour ?

That TT mod was developed long before I got involved with ST's,,, but I will take a shot at it's history. If anyone else actually tried it,, please speak up. I am sure that it sounded good,,, both as an idea,, and in practice as a performance sound upgrade. But while it seemed very innovative, when I read about it 3 or 4 years ago,,, I am not sure it can deliver much in the way of useable performance gains. But audibly,, it could sound good,, briefly,, at times. But what I have learned,,, as part of my Bazzaz project,,, is that the typical ST13 spends the vast majority of it's time at or below %40 of wide open throttle. So is the benefit achieved really worth the effort ? I suspect the same question would also be true of Robin's mod,,, but this is mostly speculation on my part,,, and I bow to actual experience. The simple analog throttle opening indicator (see photo),,, (along with the digital throttle sensor ability of the Bazzaz software) kind of opened my eyes to how much the stock exhaust flows,,, and the stock intake flows,,, for a typical throttle opening. I have documented how lean the ST13 runs overall. And,,, with intake mod's,, like K&N,,, and exhaust mod's like Del or 2-bros,,, it is even more so leaned out. Being very lean can create it's own problems, and can rob performance potential. So while I applaud the intent and the innovation of both of these mod's,,, I have not adopted either,,,,, yet,,,, CAt'

 

[Al st1100]

Honda engineers needed to meet emissions, keep the engine and other parts reliable (until the warranty ran out), and kept riders from killing themselves. Otherwise we would still have muscle cars with young adults dieing from wrapping their cars around light posts from mashing on the pedal.

You must be young and not know what killed muscle cars. Honda always made super fast bikes, CBX 1000, CBR Hurricane to name a few. 10 second bikes going back to 1987, some even were 9 second quarter mile bikes. And we still have muscle cars.

 

[Coval]

Reminds me of my time with a Yamaha GTS1000 which had two "snorkel" intakes on either side of the box. If my memory serves me correctly they were pointing backwards but some riders turned them to point forward to improve air flow. I've gone a step further and attached (vacuum cleaner) hose extensions attached to the bottom of the headlamp for ram air effect. In theory fresh, denser air should improve performance, sadly my efforts failed to bring any benefit. Luckily the changes were not destructive. But it taught me that if you want faster bike, buy one.

 

[STPaulK]

Someone mentioned the VMax mod earlier in this thread. I had an 83 Venture with the same engine (probably detuned for touring.) The VMax mod spilled over to the Venture crowd and next thing I know I got my 1/2 drill bit and went nuts all over the airbox. I then made a "hood scoop" that went under the fairing and ran a couple of hoses (sort of like the ST1100) to the airbox (ram air!) I was really proud of my work.

I ran it like this for a few weeks and got tired of people telling me my bike sounded like a bellowing bull from a distance. Seems I created a resonance chamber that peaked at 100 hz and if there was any power gain, it wasn't worth all the crap I had to put up from my riding buddies.