OK so I will be reworking my exhaust pretty soon.
Right now it's unknown brand headers that look average length. They don't look super long down at the collector but don't look particularly short either. About three feet of straight pipe and then a wide chamber muffler at the end.

I am going to put in an X pipe and extend the pipe all they way over the back axle to the rear. It currently ends under the back seats.

This is my question. I know that smaller pipe retains the low end but longer collectors give you overall better curve throughout.
What if I ran 2 1/2" or even three inch pipe from the collector to the muffler (the x pipe somewhere in between) then use smaller pipe like 2 1/4" from the muffler to the end of the pipe. Or the larger pipe up to the X pipe and reduce it there to the muffler.
Has anyone done this? will it kill my bottom end?
I have limited knowledge of exhaust but everything says run the longest collector you can, wouldn't this effectively be doing the same thing?

Thoughts?

best setup recommendations?

I currently have a 383 stroker, single plane intake, 4 speed tranny. I intend to autocross/roadrace more than drag so the top end is not what I am concerned with so much (but don't want to give up top end altogether).


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1970 Base Coupe ~ Under Construction/Rescuewww.projectgofast.com (http://www.projectgofast.com)

2 1/5" from the collectors to the mufflers then 2 1/4" to the back makes a nice sounding system with little power loss and decent ground and axle clearance.

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Custom Auto, your source for quality machine work, cores and new parts at competetive pricing right here in British Columbia 1-888-563-4050
A Canadian, EH? (with a 10 second street car)

If you're going to put in an x-pipe, follow the advice of Dr. Gas:

When selecting a size it is suggested you match the collector/ head pipe/ converter outlet diameter with the size of the crossover.

This means that you want to maintain the collector outlet size all the way to the crossover. Adding a reducer on the end of the collector creates reflected waves that interrupt the scavenging cycle you are trying to create.