Thread: exhaust back pressure

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We played with exhaust and headers on the dyno once.... Actually, it seemed that scavenging had a bigger effect on low end torque and top end horsepower more then the back pressure. We'd made up some different collectors and tried them, mainly trying to peak the torque numbers within the normal operating rpm range. My favorite to play with is the 4 into 2 into 1 collectors, and the Tri-Y headers.... But, as Glenn said the type of exhaust and what the engine likes and dislikes has a lot to do with the cam specs and the flow rates of the heads.... About all we've determined so far is that, (1) in higher rpm's, the 4 into 2 into 1 collectors had the best numbers--whether it was with open headers or with a big tube exhaust system....and (2) dyno time gets expensive when you're just playing around with minimal changes in the power.......

The 4 into 2 into 1 showed some very minor increases (like 8 ft. lbs torque, 5 hp) by pairing the pipes with consideration given to the 2 cylinder's relationship in the firing order....

Anyway, we spent a bunch of time and money and didn't really have much to show for it.....

I'm next going to try the merge collectors, and possibly a tri-y header with a merge collector....To do much more then that, I'd have to own my own dyno!!!!!!

interesting

Originally Posted by chopped66impala

interesting

Yeah, we get bored out here in the sticks and mess around with all kinds of insignificant, meaningless stuff!!!!!