[GunMetalGrey]

I'm going to be getting a Mag 2650 SC with 1 7/8" Kooks LT Headers, GESI cats and 3" pipes all the way back to the mufflers, combined with CAI and a tune for around 700whp on 94 octane for my 2018 Camaro ZL1.

I wanted to pair this with Corsa Sport mufflers because my current Borla Atak cat back is already too loud for me and I know the car will only get louder with the high flow cats and it was my favorite sounding muffler I ever owned.

My questions is, will the 2.75" size diameter inlet of the Corsa Sport muffler have any serious negative impact on reach the hp I'm looking for? Or will it have only minor implications? I'm thinking only minor but thought I'd ask.

This would be for the street only, I have different 3" inlet/outlet mufflers for the track.

Thanks

[JonDaddy82]

2” headers is your bigger problem. The Corsa axleback won’t really hurt you, but Corsa is crazy ass loud, so it may not solve your problem.

[Camaro1973]

That corsa is louder then the Borla. Do you have NPP or non NPP on the borla? Makes a big difference in sound if you have the NPP on the borla.

[JasonGofast]

Corsa with headers are loud as shit. You're better off with an NPP system like most Borlas have or that expensive one Corsa is selling now. Either that or getting some resonators.

[GunMetalGrey]

There seems to be some confusion here, Corsa sport mufflers are not as loud as Borla ATAK mufflers. Corsa extreme is roughly the equivalent to the Borla ATAK, while the Corsa sport is roughly the equivalent of the Borla S type.

Furthermore, all NPP systems open all valves wide open at wide open throttle, so the only time an NPP system could be quieter than a CORSA Sport is when the car is not at wide open throttle, and that would only be for the factory NPP system. Both the Corsa NPP and the Borla NPP quiet modes are not very quiet at all, they are more like the Corsa sport and borla S-type until they are wide-open throttle.

I’ve owned a Corsa sport muffler before and I currently own the Borla ATAK NPP cat back system that replaced the stock factory NPP system plus i’ve talked to Corsa about their new NPP system.

[GunMetalGrey]

Originally Posted by JonDaddy82

2” headers is your bigger problem. The Corsa axleback won’t really hurt you, but Corsa is crazy ass loud, so it may not solve your problem.

Thanks for the feedback on the muffler inlet size.

I’ve never heard any builder or tuner say that 2 inch headers were needed for 700 wheel horsepower. They’ve all said that 1 7/8” is plenty.

The Corsa extreme is very loud, but I’ve owned the corsa sport on my now sold 2017 Camaro SS and it’s not nearly as loud as the Borla Atak system I currently have on my 2018 ZL1

Having said all of that, I don’t know how much louder adding long tube headers and high flow GESI cats will make my otherwise stock ZL1

[soceur77]

The GTHaus exhaust is on the expensive side, but ditches the default NPP for a valve module thats controlled via remote so when you want it quiet it is, and when you want it loud its loud. Ive even recently realized that i can have a in between where i just tap the open button a couple times instead of pressing hold for 3 secs and Ill have in my opinion the perfect sound level. It will def support your HP goals, although Ive been told it wont support over 800, but thats being debated as another user with the same exhaust made 851whp.

Swift

[EDFHOBBIES]

The 3 inch makes a huge difference over 2.75 ATAK cat back wife's car is perfect can ride with NPP open and make phone calls no problem as long as your not full into throttle my 3 inch ATAk is hard to make calls even in snow mode. If it wasn't for the carbon tips I would put the OEM back on. Both 1 7/8 headers Both supercharged, both Atak's I'm cammed but its a non aggressive stock idle.

power wise I'm at 1004 the headers or cat back isn't holding me back its the fear of the 2 piece thrust bearings and main bearing failures that is.

[KingLT1]

The factory NPP has proven to NOT be restrictive even on builds over 800whp. The cats(Even being GESI) will be the biggest restriction in the exhaust. Any exhaust mods post cats is pretty much for sound only... So your exhaust setup will be fine for 700whp with plenty of room to grow.

[DFW_Muscle]

Originally Posted by GunMetalGrey

I'm going to be getting a Mag 2650 SC with 1 7/8" Kooks LT Headers, GESI cats and 3" pipes all the way back to the mufflers, combined with CAI and a tune for around 700whp on 94 octane for my 2018 Camaro ZL1.

I wanted to pair this with Corsa Sport mufflers because my current Borla Atak cat back is already too loud for me and I know the car will only get louder with the high flow cats and it was my favorite sounding muffler I ever owned.

My questions is, will the 2.75" size diameter inlet of the Corsa Sport muffler have any serious negative impact on reach the hp I'm looking for? Or will it have only minor implications? I'm thinking only minor but thought I'd ask.

This would be for the street only, I have different 3" inlet/outlet mufflers for the track.

Thanks

I highly doubt you would see ANY attributable performance change going from a 2.75" to a 3" muffler on a 6, 7, or 800hp setup. And it sounds like you have first-hand experience with Borla / Corsa so I can't comment which would be quieter / louder. But I certainly wouldn't worry about power restriction. I will say that when I went from an AWE catback system, to a header, no cat, and AWE catback system, I went from loud at WOT, to unbearable at WOT. I am now headers, catless, AWE mid-section and OEM muffler.

The 1 7/8" headers will be plenty for your build. the GESI green cats will be the most restrictive part of the system, but even then, doubtful they are choking out any power at this level.

[Jason18ZL1LE]

See my signature. Youre fine

[GunMetalGrey]

Thanks guys, I appreciate the feedback, juicedmotorsports said the same thing too, nothing to worry about.

Cheers

[GunMetalGrey]

Originally Posted by soceur77

The GTHaus exhaust is on the expensive side, but ditches the default NPP for a valve module thats controlled via remote so when you want it quiet it is, and when you want it loud its loud. Ive even recently realized that i can have a in between where i just tap the open button a couple times instead of pressing hold for 3 secs and Ill have in my opinion the perfect sound level. It will def support your HP goals, although Ive been told it wont support over 800, but thats being debated as another user with the same exhaust made 851whp.

Swift

Interesting, yeah I really don’t wanna spend too much more on exhaust, but do you know if it’s safe to track on quiet mode? Repeated wide-open throttle over and over again during a 20 minute session. Every other system seems to open the valves fully so that the mufflers don’t blow up, but maybe this system works differently?

[Camaro1973]

I keep the exhaust setting on tour mode, I have headers, green cats, and full borla atak cat back. With the valves shut, its like the stock manifold, cats and the borla atak cat back with valves open when cruising. Its only loud when you are at high rpms, or on the throttle when the valves open. I hear the headers pinging louder then the exhaust when the valves are shut.


However, when your on it past 3500rpm and on throttle it starts to sound like nascar. But i like this setup on street because you can quiet it down when needed. Catless is MUCH louder.