Carpenter Racing Exhaust

hanso said:

I been asking lots of question to the guys that make header systems and here is the low down as I understand it.
I am not saying this is 100% accurate but my take on the info I have gleaned from several reputable bike and car tuners plus info I found on the Net, No Arguments will be entered into by me

a 2 inch system is more suited to forced induction and highly modified R3 motors and on a non internal modified motor will only give benefit at high RPM where most of us do not go or otherwise not spend a lot time there, so yeah a Carpenter exhaust system is great if you are running Hi comp Hi reving cam profiles in eg carpenter 240 kit worked engines or are running a SuperCharger, in other words it is designed to work at higher revs or move large amounts of exhaust to work at its best, it will still work on a std engine but not as efficiently as a slightly smaller OD header (something about loosing velocity in the larger OD)

a 1 3/4 system will suit a stock engine and give benefits to it offering good scavenging and good all round performance but if you then wish to go to hi comp pistons and cams that work in a lower rev range eg Ponters bike with his Neville lush worked engine and Reband exhaust it will then be working at it designed level

a 1 5/8 system again will suit a Std engine and also some slight mods but not a lot more unless it is a 3 into 1 system with a decent size choke, then it has more potential for a modded engine

Again I am not looking to start an argument just stating the fact that I have found to help someone trying to decide which size/type exhaust to buy for their bike

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warp9.9 said:

Not to bust anyones arse or bubble but can you explain why when Bob Carpeter put a set of his pipes on a bone stock R3T he pulled 165 hp and 163 in torque?

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barbagris said:

He had to have used a different map surly - probably an optimised Roadster map? with 100% secondaries?. Just guessing. I don't know.

R3T owners who swapped maps on standard zorsts have seen power increases too if I recall correctly. Didn't pred's give similar figures on standard engines too.

It's annoying - I had all the formulas for this sort of stuff but lost them when I left the UK in 1990. Resonance, volume, velocities - waveform shifts. I've heard about some interesting results using vanes to spin gasses - but blowed if I can find any proper documentation - White Paper type info - not marketing. I'd love something along the lines of that bellmouth article.

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warp9.9 said:

Not to bust anyones arse or bubble but can you explain why when Bob Carpeter put a set of his pipes on a bone stock R3T he pulled 165 hp and 163 in torque?

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ruzzle said:

Hey Warp..........

Isn't 150-160 RWHP the "norm" with triple filters, decent exhaust like Preds or Reband, say 1 5/8" - and a good tuner?? Leave the filters off and might you expect 165 or so.... even without the big-bore Carp pipes??

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ruzzle said:

Hey Warp..........

Isn't 150-160 RWHP the "norm" with triple filters, decent exhaust like Preds or Reband, say 1 5/8" - and a good tuner?? Leave the filters off and might you expect 165 or so.... even without the big-bore Carp pipes??

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