Exhaust Recommendation

[TX '90 ZR1]

Am well aware that different exhaust systems have been discussed ad-infinitum. I am looking for a specific outcome.
Here's the scenario: '90 with everything stock. Looking ahead to the possibility of engine upgrade (Haibeck 510?). Without the opinions as to sound or resonance, which bolt on exhaust is the best from a performance perspective? If I need quiet I can just put the stock system back on. Quick change.
Not looking to do headers at this time. Just the best system to bolt on and still be conducive to working with the engine upgrade down the road.
Let me know which one is best.
:cheers:

[G8nightman]

Part of the 510 package is headers


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[TX '90 ZR1]

Part of the 510 package is headers


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Thanks G8nightman.
I'm aware that headers are part of the package, that is why I am trying to determine the best system (cat back) to get to go with the upgrade when done.
:cheers:

[G8nightman]

You would first determine if you want cats or not but I personally like SW or Corsa. I would do it all at the same time with out the headers just an exhaust won’t do much unless you want it to be louder than the stock exhaust.


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[TX '90 ZR1]

You would first determine if you want cats or not but I personally like SW or Corsa. I would do it all at the same time with out the headers just an exhaust won’t do much unless you want it to be louder than the stock exhaust.


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Thanks again,
Honestly, I would like it a little louder than stock. Also, if I do the engine upgrade would go without cats as the car would be a "keeper" at that point.
I've been leaning towards SW, just wanting some feedback as to what others think.
:cheers:

[lfalzarano]

Keep the stock mufflers for looks and install electronic cutouts just before them.


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[WARP TEN]

Keep the stock mufflers for looks and install electronic cutouts just before them.


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Good advice. I did that on my 95 which had a Haibeck 510 HP package done in 2014. Here is a link to a recent post on the subject that contains additional links to the earlier installation posts. My post is #8 on that page

http://www.zr1.net/forum/showthread.php?t=30164&highlight=exhaust+cutouts

Hope that helps. Here are a couple of teaser pics--Bob

[TX '90 ZR1]

Thanks Lou and Bob.
I had considered doing the cutouts. On Marc's site I read it to say the exhaust needs to be changed. Here's the quote.
"Headers are installed. Click here for more information on headers. A low backpressure exhaust system is required. The Corsa system works best. The B&B Triflow with an x-pipe also works well."
Cost of installing the cutouts goes pretty far towards a different system, plus my stock system is still unmolested if I don't do the engine and want to go back stock.
Just throwing ideas around at this point. Trying to make up my mind how deep I want to jump in!

[billschroeder5842]

TX 90, if you are going to work with Marc, he recommends (or at least his studies prove) that a Corsa system works best for cat back and he recommends SW for the headers. As you have seen on his site as he has a lot of presentations/studies.

I have a set of SW headers with Corsa exhaust and Steve Schroder (Cross Flags performance) a ZR1 owner did my install and tune. I will vouch that the SW, Corsa and tune combo is top notch. No mistakes there.

[TX '90 ZR1]

TX 90, if you are going to work with Marc, he recommends (or at least his studies prove) that a Corsa system works best for cat back and he recommends SW for the headers. As you have seen on his site as he has a lot of presentations/studies.

I have a set of SW headers with Corsa exhaust and Steve Schroder (Cross Flags performance) a ZR1 owner did my install and tune. I will vouch that the SW, Corsa and tune combo is top notch. No mistakes there.

Thanks for the feedback Bill.
I believe I am pretty much sold on the Corsa exhaust at this point. I notice there are 2 systems. Do you happen to know which one is better or the recommended one?
Saw the numbers from your dyno run. Are the only modifications you have done the exhaust, headers & tune? Pretty impressive if so.
I am still pretty much on the fence whether to do any mods on my car as I have spent the last year making sure every last little thing is working as it should. Pretty sure I don't want to do anything that I can't put back to stock, but I would like to pump up the performance a bit.
Are you attending the South Texas get together in April? I plan to attend and try to pick up some pointers from other Z owners more experienced than me.
Thanks again for the feedback. :cheers:

[GOLDCYLON]

Thanks for the feedback Bill.
I believe I am pretty much sold on the Corsa exhaust at this point. I notice there are 2 systems. Do you happen to know which one is better or the recommended one?
Saw the numbers from your dyno run. Are the only modifications you have done the exhaust, headers & tune? Pretty impressive if so.
I am still pretty much on the fence whether to do any mods on my car as I have spent the last year making sure every last little thing is working as it should. Pretty sure I don't want to do anything that I can't put back to stock, but I would like to pump up the performance a bit.
Are you attending the South Texas get together in April? I plan to attend and try to pick up some pointers from other Z owners more experienced than me.
Thanks again for the feedback. :cheers:


2 Corsa systems for the LT5 ? I think there are one for the L98 and one for the ZR-1..... Then the Later LT1s and LT4s. Total of 4 systems for the C4 run


However you have more options in the tips now. Black etc

[billschroeder5842]

Kenny- what part of Texas do you live? I'm up in DFW and happy to let you drive my car.

The only modifications to my car are the SW headers and the Corsa system. However I asked Steve to do new injectors (FIC from Jerry's), coils, wire and new plugs along with his tune.

I think that the tune made a big difference and is essential after any serious exhaust work as all the AF ratios are altered. When I was at Steves shop, he showed me the charts/graphs/tables on his computer of the exact tune my car was getting before we ran the dyno. Even after the dyno "power pulls" Steve took out the chips and made some adjustments that really made a difference--- every car has a unique fingerprint.

You are on the right path!

[GOLDCYLON]

Kenny- what part of Texas do you live? I'm up in DFW and happy to let you drive me car.

The only modifications to my car are the SW headers and the Corsa system. However asked Steve to do new injectors (FIC from Jerry's), coils, wire and new plugs along with his tune.

I think that the tune made a big difference and is essential for any serious exhaust work as all the AF ratios are altered. When I was at Steves shop, he showed me the charts/graphs/tables on his computer of the exact tune my car was getting before we ran the dyno. Even after the dyno "power pulls" Steve took out the chips and made some adjustments that really made a difference--- every car has a unique fingerprint.




Bill did you get your shroud plug ?

[WARP TEN]

Thanks Lou and Bob.
I had considered doing the cutouts. On Marc's site I read it to say the exhaust needs to be changed. Here's the quote.
"Headers are installed. Click here for more information on headers. A low backpressure exhaust system is required. The Corsa system works best. The B&B Triflow with an x-pipe also works well."
Cost of installing the cutouts goes pretty far towards a different system, plus my stock system is still unmolested if I don't do the engine and want to go back stock.
Just throwing ideas around at this point. Trying to make up my mind how deep I want to jump in!

If you want a stock look but better flow the later exhaust systems have a much less restricted center resonator than the 1990-91 one. Marc is right that the Corsa system is a high flow system--you can look through the resonator and mufflers--and it uses the Helmholtz Resonator technology to eliminate or minimize resonance (drone) as does the stock system. With my '93 I experimented with several exhaust systems in the mid-'90s including Borla, Power Effects, B&B and Corsa. Corsa was a good as the stock system for eliminating resonance; the others were not. (They may well have been improved since then). I liked the sound of the Corsa but your enjoyment of the sound of a system may be different than mine. I had a Corsa on the '93 for most of the years I owned it, and on the '95 as well. As an old guy, though, I just got tied of a loud exhaust all the time so I eventually switched back to stock with cutouts on the '95. I'd say you can't go wrong with a Corsa if that's what you want. And there are plenty of ZR-1s out there with Corsas that you can sample. --Bob

[TX '90 ZR1]

2 Corsa systems for the LT5 ? I think there are one for the L98 and one for the ZR-1..... Then the Later LT1s and LT4s. Total of 4 systems for the C4 run
However you have more options in the tips now. Black etc

After looking at the listings (pasted below) it appears the only difference between the 2 might be the outlet tips. Sure seems like a big dollar difference if this is all it is.


Corsa Corvette C4 ZR1 (LT5) Dual Exit w/Twin Pro-Series 3.5 Tips; 1990-1995
Corsa Performance
CATALOG # 007129
MPN #: 14117
$1,466.99


CORSA Corvette Cat-Back Exhaust C4 ZR1 5.7L V8 LT5 Sport - 2.5 Inch Dual Rear Exit with Twin 3.5 Inch Black Pro-Series Tips; 1990-1995
Corsa Performance
CATALOG # 00659089
MPN #: 14117BLK
$1,680.99

I got these from the LM Performance website. They are offering a 5% discount and free shipping.
Any recommendations of other places to check?
Appreciate the feedback. :cheers:

[billschroeder5842]

Kenny,

I went direct to CORSA for my system. There is no real discount as they need to respect thier dealer network, but I was able to confirm what they had in stock and shipping direct saved me a couple of days.

Because I'm a freak, I opted to go with the black tips on the Cat Back as they matched my theme of dark red metallic and black. I ordered on Tuesday and had them on Friday. I had my buddy Allen over on Saturday and we did the full on swap in a couple of hours. Pretty straight forward.

GC.... Thanks and yes I did. I ordered the ones your suggested and it worked.

[TX '90 ZR1]

Kenny- what part of Texas do you live? I'm up in DFW and happy to let you drive my car.

The only modifications to my car are the SW headers and the Corsa system. However I asked Steve to do new injectors (FIC from Jerry's), coils, wire and new plugs along with his tune.

I think that the tune made a big difference and is essential after any serious exhaust work as all the AF ratios are altered. When I was at Steves shop, he showed me the charts/graphs/tables on his computer of the exact tune my car was getting before we ran the dyno. Even after the dyno "power pulls" Steve took out the chips and made some adjustments that really made a difference--- every car has a unique fingerprint.

You are on the right path!

Hey Bill,
The closest town to where I am most of the time is Brownwood. This would be about 160 miles or so southwest of you in Southlake.
I hope to get to the get together the first of April and check out some other cars. Do you think you might be there? The one I have now is the only one I have seen in person since I had the new one back in the early 90's!
Still undecided as to how far I want to go with this car. It is very nice and everything works, but if I drop another 10 to 15K in it I am way out of the ballpark if I decide to get something else.
I can sort of justify the expense of an exhaust system just for my own enjoyment, but will be a while before I decide to go "full out" with it.
:cheers:

[rush91]

After looking at the listings (pasted below) it appears the only difference between the 2 might be the outlet tips. Sure seems like a big dollar difference if this is all it is.


Corsa Corvette C4 ZR1 (LT5) Dual Exit w/Twin Pro-Series 3.5 Tips; 1990-1995
Corsa Performance
CATALOG # 007129
MPN #: 14117
$1,466.99


CORSA Corvette Cat-Back Exhaust C4 ZR1 5.7L V8 LT5 Sport - 2.5 Inch Dual Rear Exit with Twin 3.5 Inch Black Pro-Series Tips; 1990-1995
Corsa Performance
CATALOG # 00659089
MPN #: 14117BLK
$1,680.99

I got these from the LM Performance website. They are offering a 5% discount and free shipping.
Any recommendations of other places to check?
Appreciate the feedback. :cheers:
I believe your right....I think the extra $200 is for the black tips. My 2 cents is exhaust are subjective as has been said on here. Corsa is just way to obnoxious to me, and I cant stand how the tips stick out of the back. In my mind the tips should be flush with the bodywork. I'm also in the frame of mind that there is nothing wrong with the stock tubing....I plan this summer on swapping my 91's resonator with probably Magnaflows 12468 muffler. And chopping off the mufflers and adding these from Corvette Central...


https://www.corvettecentral.com/c4-84-96/exhaust/magnaflow/91-magnaflow-exhaust-muffler-with-lt1-tip-324513?returnurl=%2fc4-84-96%2fexhaust%2fmagnaflow%2f%3fcount%3d9


keeps the look of the LT tip, I know these tips didn't see production until 1992, but I always loved the clean look of those tips.

[GOLDCYLON]

After looking at the listings (pasted below) it appears the only difference between the 2 might be the outlet tips. Sure seems like a big dollar difference if this is all it is.


Corsa Corvette C4 ZR1 (LT5) Dual Exit w/Twin Pro-Series 3.5 Tips; 1990-1995
Corsa Performance
CATALOG # 007129
MPN #: 14117
$1,466.99


CORSA Corvette Cat-Back Exhaust C4 ZR1 5.7L V8 LT5 Sport - 2.5 Inch Dual Rear Exit with Twin 3.5 Inch Black Pro-Series Tips; 1990-1995
Corsa Performance
CATALOG # 00659089
MPN #: 14117BLK
$1,680.99

I got these from the LM Performance website. They are offering a 5% discount and free shipping.
Any recommendations of other places to check?
Appreciate the feedback. :cheers:


yep the extra $200 is for the anodized black tips

[Paul Workman]

Like U, I set my upgrading in stages, beginning with a 'cat-back' and progressing as $ allowed.

The two schools of thought are the Corsa and the 3" w/ the SW "X-pipe" and B&B Fusion system.

Marc's data supports the Corsa, while Pete Polatsidis has data that supports the 3" system. One example does not a trend make: more research needed before an absolute conclusion can be made. But, if in one case the Corsa worked best and in another the 3' system worked best, it suggests there can't be a lot of difference between them, power wise. However, the Corsa has for a long time been the choice for drone reduction. However, mods including use of the NPP "flapers" (installed on one of the two muffler outlets of each muffler) are quite effective at reducing drone as well.

Regardless of which system you install, know that the stock 90 cat-back is VERY restrictive. So, installing a free flowing system will require a modification to the chip calibration. And, if you revert back to stock, the calibration too will have to be reversed. Just sayin.

Marc has his car's tune optimized for running w/o mufflers (drag racing). You'll have to ask him what muffler he uses for street driving. But, the cut-outs idea appeals to me as perhaps the way to go: best of both worlds at the touch of a finger? (Bob Banks is a good source for a testimonial.)

Mine is a hybrid 3" system w/ a SW headers and "X-pipe" and Magnaflow mufflers (restrictive), and NO cats. One day I may opt for cut-outs. But, if I had it to do over again, I'd have to give the Corsa another look. But, I can tell you this: My wife has the old B&B 3" cat-back, and brother does it DRONE! Fortunately, her 91 ZR-1 also has a 4.10 gear so she can cruise in 6th gear and easily keep the rpm out of "the zone".

The simplest, and arguably the best performing system, one might spend the money and go with the Corsa and be done with the experimenting. Me? I like whatever works (for me). After 11 years I'm still not settled.

Clear as mud???:cheers:

[JFFerner]

I read your note here about chip calibration modification when converting to a free flowing exhaust system. What happens if cut outs are used, assuming one usually drives with the cut outs closed, opening them only occasionally?

[TX '90 ZR1]

Paul,
Clear as mud??? Yes, but surprisingly I understand what you are saying!
Good point about the tune.
Also, the previous post by JFFerner raises a good question. Anybody have an answer? :confused: :cheers:

[Mr Blue]

IF my understanding is correct, calibration should be for the most free flowing exhaust condition. This is so that you don't run overly lean in WOT and fry something. If you have cut-outs, you might run a little rich in WOT with them closed,but that's safe. In part throttle, as I understand it, fuel is governed by O2 sensor and the ECM. Someone correct me if I am wrong.

[Paul Workman]

Marc or Dominic or Pete can better answer. However, IIRC when I asked Marc about it, he said he tuned it with the mufflers removed - which would make sense if tuning for peak performance (i.e., mufflers off during the race or high performance demand). Also, to avoid LEAN conditon at WOT.