1994 Mufflers

[32valvZ]

Originally Posted by jeasen

I want to upgrade the exhaust on my 1994 ZR1. My first thought was Corsa, but after reading a report on the 1994 exhaust system by Haibeck Automotive it appears that the bottle neck in the 1994 factory exhaust is the mufflers. Only 1 psi difference across the cats, no difference in pressure across the resonator, but 4 psi increase in front of the mufflers. A Corsa system would not do anything for the difference in pressure across the cats, and there is nothing wrong with the resonator. So maybe just a muffler change??

Anyone know of a non restrictive replacement muffler for the 1994 ZR1? It appears the the diameter of the pipes leading to the factory muffler is 2 3/4". The LT1 mufflers are 2 1/2" or 2 1/4" and would be no improvement over the stock ZR1 mufflers.

There is nothing wrong with my exhaust system I just want to add a little more performance.

I guess I could just remove the mufflers and replace them with a straight pipe but I am concerned about the noise that would make?

Anyone have any suggestions or thoughts on this?

You will never notice a performance difference by changing mufflers on any car. Sound difference, yes, but not a noticeable SOTP feel. Listen to us and bolt on some headers and then a nice Corsa or B&B cat back system. Youll have performance along with the sound improvment.

[jonszr1]

Originally Posted by 32valvZ

You will never notice a performance difference by changing mufflers on any car. Sound difference, yes, but not a noticeable SOTP feel. Listen to us and bolt on some headers and then a nice Corsa or B&B cat back system. Youll have performance along with the sound improvment.

cont rary to what was said before you can get a performance increase by changing mufflers .hib got a 18 hp increase by going to a 3 in 3 chamber flowmaster muffler , i got a similar increase by going to a custom dr gas 21/2 in system from the flowmaster system

[jeasen]

Happy Thanksgiving everyone. Thanks for replying to my post.

It looks like there are several opinions when it comes to answering my question.

At this point it appears that a 3" straight pipe in place of the mufflers is the best answer. If I cannot stand the noise then I can deal with that later.

Any other opinions or comments out there?
Jeasen

[Aurora40]

Originally Posted by jeasen

Happy Thanksgiving everyone. Thanks for replying to my post.

It looks like there are several opinions when it comes to answering my question.

At this point it appears that a 3" straight pipe in place of the mufflers is the best answer. If I cannot stand the noise then I can deal with that later.

Any other opinions or comments out there?
Jeasen

I had basically what you are talking about. Stock pipes, LT4 resonator (the '90-91 resonator is much smaller than yours), and Dynomax 3" Ultraflow mufflers.

With stock manifolds it sounded really good, but there was definitely more resonance than stock. With headers it sounded REALLY good, but there was a ton of resonance. I got sick of putting earplugs in for any longer drives, and in winter with the windows up, so now I sport Corsa's.

I'd say maybe try a 2.5" muffler vs 3". Maybe it will cut down on the resonance some more.

[jonszr1]

in messing around today with my blk car ,i found that i cut a ton of resonance out of the car by extending the tips after the mufflers 4 in beyond the rear valance . i could believe how much quieter it5 got inside the car, some may not like that look and i totally understand ,butr my old 57 yr old ears just needed some peace and i dint want to give up the performance gains that my dr gas exhaust had given me , by the way its a 21/2in exhaust with an xpipe . the idea came from a muffler guy who is spending the week with us . he also thought that if we cut a resonator in half and gut it then cut openingsso that it fit over the x pipe fill it with steel wool that it might really also quiet things down . he says the resonance comes from in part due to the pipes vibrating at a certain rpms.dont know if hes right but it kinda makes some sence , and what the heck i thought its worth a try . .hope every one has a great t day

[jonszr1]

i am in the same boat as you but will see if i can find it for you

[jonszr1]

in fact the article is on our site . go to the main registry page and click on articles . when that comes up. on the left side of the page there is a list .click on articles again and you will find it under 38 hp gain .let me know if you cant find it

[jeasen]

jonszr1, thanks for your help. I found it.

Jeasen