I recently went to the shop by my house and was talking to one of the guys that works there and he was telling me about putting a 3" Thermal Exhaust on my GS. He also said that it would lose that much pressure. But I remember reading on here about 2 1/4 and 2 1/2 are more than sufficient. Anyone here have 3" on a non-turbo. I think is saw someone on here with 3" Thermal, but I don't remember who. any help would be appriciated. Thanks

3" is too big for N/A if you don't plan to go high HP turbo soon (like in a week or 2) then stay with 2.5 your car has 2.25 stock

Does the muffler matter, or is just the pipe that will take away power?

Jay | Black '98 GS

AEM CAI ... NGK BKR6E-11 spark plugs ... Motor mount inserts (not yet installed) ... Test pipe (not yet installed) ... Apexi N1 muffler (not yet installed)

would anything happpen if I did get it put on?

Loose a little bottom end.

on the other hand, Jake (Saberkahn) has the greddy power evolution on his RS, 3 inch piping if I'm not mistaken, and still barks 4th gear, so go figure

would it hurt the engine any if i got the 3" on, because it sounds really mean.

The muffler size does not really matter. it is the size of the exhaust piping that truly matters. If you do decide to take the 3" exhaust, you will lose a lot of low end power, and your car will be a lot louder than a 2G NT with smaller piping. If you are not going turbo, stay with 2.25"-2.5" piping.

what really matters is back pressure. If you maintain the stock cat and run 3" it will work, sound good and look great. I put the thermal on mine before i went turbo. It didnt seem worse to me. I then got turbo cut out the cat. Then from the turbo all the way to the cat back is 3" .If you can pick it up from 500-575 get it late mike

I've got a Thermal R&D 3" Turbo catback, & everyone's right about the low end. There's a fairly good loss of power there, but I think it really sounds great, very deep & throaty. Once you get around 1500-2000 rpm's though everythings fine as far as acceleration. Mine really doesn't "crackle" like some of the other exhausts when & I gun it either, which is one thing that I really like about it. I also am planning on going turbo next year.

So it once again it's like everyone said. If you're not going turbo probably get a smaller diameter.

Yes, I have the Thermal R&D 3" as well on my 98 RS. I lost a lot of bottom end power but at higher speeds/RPMS I feel a little more of a pep actually. Maybe it's just in my head. I get my Hahn stage 1 in a couple weeks though...so like everyone said, go turbo if you're getting the 3". Unless you don't mind being a little slower. I don't think it will actually hurt your engine or anything.

I've got the Thermal 3" but of course I'm HRC staged 2. So what if you lose alittle, it's mean enough that the sound will get you way from thinking about loseing a few horses. :thumbsup

i have a sound bite of my thermal...email me and ill send it to u, or someone can host it?