Which exhaust?

MtDewd

Registered User
I've recently puchased a 91 SC 5 speed with a bad motor. Now that I have rebuilt the engine, it's time for exhaust. After scanning the the forums I've noticed a lot of people are running or recommend a 2 1/2" to 3" to 2 1/2" exhaust setup. I was planning on running a 3" from manifolds to mufflers. I've ported and polished, magnafluxed, and port matched the heads with the intent to let this motor breath. Which exhaust setup is better, 2 1/2" to 3" to 2 1/2" or a full 3"? And what about the resonator, use one or not?
 
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The use of a resonator on these cars is mandatory to prevent drone, due to the 6 cylinder engine. If you don't mind the sound, deleting it will probably increase flow. Most dislike the sound without one, but some have found using extremely long mufflers will almost compensate for not having one.
 
I agree with Digital. I would definitely use a resonator (hell it's really just a muffler). I've got a magnaflow on my '95 and it is not too loud. Trust me, the drone in the cabin from a real loud exhaust on these cars gets real old real fast. It's not like cruising down the street in a big block Chevelle with the headers uncapped. Others have tried to eliminate the resonator with an x-pipe, but I have not heard anything confirming that that setup would yield good results. Also, I think 3" all the way back would be WAY too big. You may want to copy one of the systems for sale at supercoupeperformance.com and have the pipes bent at your favorite exhaust shop.
 
Thanks for the advice. It will help out a lot. I went to supercoupeperformance.com to take a look at their exhaust and copy one of theirs and they show a full 3". Anyway, I think I'll stick with the 2.5 3 2.5 until I can get up to 350 hp. Thanks again!
 
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