Delkevic Exhaust - performance

[Grabcon]

I have searched and found a number of threads on the Delkevic Silencers,. A lot of pros and cons on the loudness, etc. What I am more interested in in is the overall performance on a ST1100 (1991). My current exhaust is rock solid and really no need to replace other than personal preference. But if there is no gain in performance, mileage, etc., then it is just a noise think which looses at the end of the day.

So replacing stock silencers with either the Oval or Tri-Oval Delkevic silencers make a performance difference?

Does adding the Delkevic Down Pipes and silencers make any difference over just silencers?

In the world of vintage 4 cylinder hondas exhaust can make a huge difference. Does the same apply here with the ST1100?

Thanks much

 

[saaz]

Unfortunately on the ST11 the main restriction is designed into the intake system. With the long intake tracts meant to give a broad spread of power, this limits any performance increase on the cheap from just changing the air filter and exhaust. The get any performance increase you have to do a lot of retuning of the carbs and increase the air intake of the air filter housing. This will give you an idea http://www.st1100.org/steinborn/index.html

I fitted some staintunes to mine, mainly as they were cheap being factory seconds the owner did not use or want, and one of my exhaust hanger brackets had broken off. No performance chnage to speak of.

I understand where you are coming from, as 20% power gains from air filer change and 4-1 on a Japanese 4 was so common years ago. No so for modern bikes of any sort, unless it is a big V twin strangled to meet noise requirements.

 

[Grabcon]

Thanks very much for the insight and the link. It is an interesting article. I see that the unfortunate part of tuning these STs is carburator access. But on the other hand I use working on my bikes as theropy from all other things, Work, KIds and the wife. Opps did I really say that.

 

[saaz]

Yes you did say that, but we won't tell!

If the carbs were easier to get to for changing jets I would have considered some changes, but any noticeable improvements seem to also detract from the character of the engine that I like. The other old fashioned way to get more torque all over is a big bore kit, but again seems a limited option for the ST11.