Greetings . . . Twisted is right on . . .

As I see it most hot rodders have a tendency to lean toward a 'big is better' theory on exhaust systems. This is a drag-strip mentality which is well founded at top end RPMs. But for the street you end up with way to much pipe at low RPM. This translates into lots of air mass to move - resulting in very low exhaust gas velocity - which affects throttle response.

If you're after that Ed Roth 'rat fink' look at the rear bumper you're better off with an echo-can set-up where only the lengths of pipe under the trunk are big diameter and the rest is optimized for the HP your ride is actually putting out. Check out Rap Rap's ride for an example of over the top tail pipes. Sweeeeeet!

I find this article on Exhaust Theory informative.

Considering its content I would say that any ride south of 200 hp is hard pressed to take advantage dual 2 inch pipes. I'd be leaning toward 1 7/8 especially with the cam change where there is overlap. A compromise would be 'bigger' head pipes to the muff and something less in the tail pipes (which by the way is the typical stock configuration - cause it raises exhaust gas velocity).

Years ago I had a three two seven v thingie with some significant mods in the block. For driving on the street I had it set up with stock exhaust manifolds feeding dual 2 1/4 inch head pipes into 36 baffle packs and 2 inch tail pipes. This was certianly a 'restrictive' setup for the top end - but it was very peppy around town which is where I drove that big '68 Impala most times. That engine was putting out well north of 350 hp. And with them baffle packs I could really get my foot into it and not draw much attention.

regards,
stock49

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