KEI069: nice info, did you look at link I posted?

Damn, THATS handy to know :hmm:

 

Thanks

Wow thats awesome! Would you have any before/after dyno sheets of your extractors for curiosities sake?

 

Unfortunately i don't have any dyno sheets, it has been a cuople of years since ive made extractors

but i was working closely with the Alfa club backe then when i came across this information.

The Alfa guys started a budget race class for members where only early Alfa boxers and

Alfettas with the 1.5 litre flat four engines were used and only modifications allowed were

intake/exhaust and suspension/tyres, to try keep it fun and competitive and most of all cheap.

We had two cars running 4-1 design pipes using the formula and four cars using 4-2-1 design pipes

using a slightly modified version of the formula. The rest of the exhaust sytem was the same on all

cars which was 2" with one straight through muffler and a resonator. Both cars with the 4-1 pipes

were the leading cars during most races (when other problems didnt arise)

 

I'm not saying this is the only method just one i found that seem to work very well. Another industry

guru is DiFillipo who also supports this theory or similar and he does do a lot of dyno work.

 

All the best guys, i hope the info helps someone a little at least.

cheers

Justin

Justin when that was tried where the primary pipe lengths the same between the 4-2-1s and the 4-1s?

 

also keep i mind that every engine behaves different, like the example I gave earlier with the 3sge engine earlier. Either way it would of been pretty interesting to see the results.

 

I forgot to mention I know of two people who have tried going from 4-1s to 4-2-1s and they picked up a stack of power in the mid range. I want to see this for myself and I have a set of futisubo extractors that I will try out and compare to my own 4-2-1 pipes.