Exhaust Question

[paulsenior]

I have a 91 Z-28 5.0. for exhaust I have stock manifolds heading to a stock cat. after the cat I have one three inch pipe that splits into dual just after the axel. What kind of system is this, and what are the pros and cons of this system.

[89IROC&RS]

what you have is a standard cat back system. i assume you also have a muffler. pro is that it fits lol, a true dual system is very hard to squeeze in there. the 3in system should be fine for flow up to a hot street strip 383. as to what company made it or if its stock, no way to tell ya from here

[paulsenior]

I do not have mufflers on my car, just straight pipes with that said what kind of HP increase might I expect from this system?. can someone tell me the difference between the Z anf the iroc

[89IROC&RS]

strait pipes might actualy cost ya some power, cuz backpressure is good for most engines, just like anything else, too much is bad, but a little is good, as far as the difference between a Z and an IROC, the IROC was the nameplate for the Z from 1985-1989, before and after that, it was called the Z-28. but im not exactly sure about the years. but they are basicly the same car.

[paulsenior]

Can you recomend a good muffler, any ideas on the HP increase that I have with my system?

[ridge_runner]

and muffler is a good performance muffler, its all about the sound you like, try to find some people with a similar car with different exhaust systems, i kno someone who has the 40 series by flowmaster and it sounds pretty badass

[Chevyracincamaro]

borla sells just the rear portion of their cat-back (i.e. the muffler and tips)

[89IROC&RS]

i have the 80 series muffler from flowmaster, and edelbrock headers, and it sounds like a pro stock car. i love it

[Lotus49]

actually.. i have the same system you have. i have a 5.7 but its 2 into 1 into 2 out of the mufflers, ive tried no exuast like you have.. to loud and it cost me about 20 hp .. easy 20 hp. so what i did was just take off the cat.. which maybe gave me the 20 back and gained me about 10-15.. but it was a noticeable difference, i also put 3" tips..(about a 2 feet long) out where the tailpiles are.. they dont extend 2 feet from the bumper they just go back to where your pipe comes out of the muffler. makes it sound so much better

[1992RS]

Well actualy Iroc, during the years of the Iroc-Z there where still Z-28s. The Iroc had a little more umph and a different paint job I believe. But there where both of em. It's just that the regular ol Z's didn't sell as well as the irocs.

[89IROC&RS]

? not to sure about that man, cuz 1990 is listed as the "return" of the Z28, my IROC is an IROC-Z as in IROC-Z28 i have multiple Z28 badges on my car, and my build sheet has Z28 as one of the three digit codes. im pretty sure that the IROC displaced the Z28 name durring those years. and when the IROC died off, the Z28 name returned.

[Chevyracincamaro]

was the camaro ever even used in the iroc races?? i know that they used the ws-6 one year in the very late 90's or early, um, 2000's...

[-= c a m a r o =-]

yea it was... why else would they name it iroc-z?

[89IROC&RS]

the camaro was used for the 1975, 1976,1977, 1980, 1984, 1985 seasons of the IROC racing series.

http://www.iroczone.com/images/gallery/84iroccamaro.jpg

http://www.iroczone.com/images/gallery/85irocracer.jpg

[DaMoNe6969]

Originally Posted by 89IROC&RS

? not to sure about that man, cuz 1990 is listed as the "return" of the Z28, my IROC is an IROC-Z as in IROC-Z28 i have multiple Z28 badges on my car, and my build sheet has Z28 as one of the three digit codes. im pretty sure that the IROC displaced the Z28 name durring those years. and when the IROC died off, the Z28 name returned.

That is very true.. There was no Z28 and IROC at the same time.. The IROC took over the Z28 from 85' to 90 1/2 I believe.. I dont know what GM did with the badges though... Cuz I have a 91' Z28, and my dash says IROC Z

maybe they just had a crate of extra emblems they needed to get rid of??