Tom M'Guinn

In my car, a bursche test pipe provided a noticeable bump in power over a stock exhaust with cat. Going from the 2.5 inch bursch to the 3 inch SFR testpipe was not as noticeable.

PorscheDoc

I run a magnaflow muffler, which is a straight through muffler like the stock cars. Sounds level is very nice and burbly around town, not loud, but when you are getting on it, it growls a bit.

On my red 86 that I am parting, it has the same setup, but a flowmaster 40, which is a bit louder.

nize

the turbulence of the gutted cat will be improved by a straight pipe. this should be pretty obvious.

if you're staying with the stock exhaust plumbing, you can't beat the sound of the stock muffler. the stock muffler is already straight-through with zero restriction.

DrZ1

"if you're staying with the stock exhaust plumbing, you can't beat the sound of the stock muffler. the stock muffler is already straight-through with zero restriction."


My muffler has aproprox 120 miles, I guess as I bought the car w/ 97k. With this high milage, could there be collapsing/ deteroration or a reason to change?

Steve

nize

depends on the environment i guess. the last three stock systems i've seen with over 150k miles on them were in great shape.

then i saw one with under 100k miles that had deteriorated.

the stock system is stainless, fyi. a lot of people mistakenly think it's mild steel.

Cory9584

The stock system is pretty heavy, another good reason to upgrade

IPSC

I have a gutted cat and a 3 inch cat back that I picked up cheap. I keep wanting to go to a full three inch but at this point I don't think it will help much. Still want to do it though...

IPSC

Tom M'Guinn

My original muffler rotted/rusted and literally broke in half at about 40k miles. I replaced it with new factory muffler and it still looks new after another 40k. Luck of the draw I guess (or more likely the effects of my car spending its youth near the ocean).

skene

I gained 10psi at 3000rpm by ditching my cat and getting a 3" pipe. Of course my cat was so clogged that the mechanic got his scope stuck in it trying to check it.

I love the sound of the test pipe with the stock muffler on there too. It's basically a bit deeper then stock but the same kind of sound. I think it's nicer then the full 3" systems, not as loud or raspy as the ones I've heard, but I probably loose some power with it.

Keithr726

OK, you will see a improvement in spool up and power with a testpipe, 2.5" or 3" really doesn't matter much. Dfastest951 has over 500hp and is still using a stock sized 2.5" B&B exhaust. I have a bursch testpipe and B&B cat-back. B&B and Dansk make great stock sized fully polished cat-backs just the Dansk is half the price of the B&B unit, I wish I would have known that. Both dansk and B&B make 2.5" testpipes too. The testpipe does make the car louder and sound much more sporty. I had a some what new high flow cat and still saw an improvement in power and sound. The cat also works as a muffler so it is like deleting a muffler. The exhaust itself is also much cooler now due to the fact there is less restriction. If you live in a state where the is a lot of emission BS, like CA, then I recommend you get a lindsey racing or speed force racing exhaust since they offer a "clamp on" style cat with their 3" systems.

I replaced my original exhaust at 118,000 miles, it had a small hole right after the muffler but was in OK shape overall, even if it was ugly. I did like that it had a straight through muffler (B&B doesn't) but the B&B is still louder. I regret getting rid of the old exhaust only because I could have made a straight pipe out of it for a day at the track or when I feel like being loud.

B&B catback with bursch testpipe and crappy camera
http://youtube.com/watch?v=GXQAqCPqAd4