[ninetres]

Originally Posted by mlee

I had 3" full Corsa on my 5th Gen... but 2.75 may be a better fit on the 6th Gen. Performance wise I doubt there is any difference.

Not at stock-ish power levels. I agree.

[brduke]

SO...What are the pro / cons when discussing Borla vs Corsa?

Price
East of install
NPP still works
Looks
Size
Long term durability
Warranty
.......

(almost like all the car shootouts we read about...and the final score/winner is...)

[mlee]

Originally Posted by brduke

SO...What are the pro / cons when discussing Borla vs Corsa?

Price
East of install
NPP still works
Looks
Size
Long term durability
Warranty
.......

(almost like all the car shootouts we read about...and the final score/winner is...)

Mostly sound preference. They are both top notch.

I believe Borla keeps NPP, but Corsa has some bad ass black tips. The rest of it is a toss up.

[Can'tHave2MuchHP]

Originally Posted by brduke

SO...What are the pro / cons when discussing Borla vs Corsa?

Price - Very close, Corsa may be cheaper as Borla went crazy with pricing on G6 Camaros
East of install - Tied
NPP still works - Borla only
Looks - IMO Corsa black tips
Size - No idea
Long term durability - No idea
Warranty - No idea
.......

(almost like all the car shootouts we read about...and the final score/winner is...)

Really dead even in probably every way. Exhaust sound is basically impossible to convey without hearing it and even then there's not an easy way to explain differences.

Corsa has a different sound than most exhausts and it's one I happen to love. IMO it sounds more pissed off, "sharp".

[Can'tHave2MuchHP]

Originally Posted by ninetres

Post links to the 2.5” high hp builds please.

What counts as high HP? There are lots of 5th gen ZL1s running stock cat-backs with 650-800 RWHP. There's also tons of C6Zs with stock axle backs which are 2.5". Lots of people with stock muffler CTS-Vs which are 2.5". All of these cars when modded are 600 RWHP or more. I have a buddy with a ZR1 that's 850 RWHP with stock axle back. All in all, most people put axle backs on if they want a different sound. A majority of restriction happens in the Headers/collectors/cats/X. Could you pick up power with 3.00" instead of 2.75"? Probably but how worth it is it and how much?

[ninetres]

Originally Posted by Can'tHave2MuchHP

What counts as high HP? There are lots of 5th gen ZL1s running stock cat-backs with 650-800 RWHP. There's also tons of C6Zs with stock axle backs which are 2.5". Lots of people with stock muffler CTS-Vs which are 2.5". All of these cars when modded are 600 RWHP or more. I have a buddy with a ZR1 that's 850 RWHP with stock axle back. All in all, most people put axle backs on if they want a different sound. A majority of restriction happens in the Headers/collectors/cats/X. Could you pick up power with 3.00" instead of 2.75"? Probably but how worth it is it and how much?

So no links?

600whp is damn near what a stock ZL1 can put down. I said thatd be fine with 2.75”. I’d bet a tall stack that a car that’s making 850whp on a dual 2.5 or 2.75” exhaust would pick up meaningful HP by running a 3” or larger system. I’d also bet that a lot of high HP cars with stock muffler systems have cut outs.

[kttxz06]

Originally Posted by brduke

SO...What are the pro / cons when discussing Borla vs Corsa?

Price
East of install
NPP still works
Looks
Size
Long term durability
Warranty
.......

(almost like all the car shootouts we read about...and the final score/winner is...)

Go to 5:50. I went with Corsa due to me having it on my Z06 and it's just my favorite exhaust for the lt4 platform. And the black polished tips are sick. Other than that, just preference really.

[brduke]

Daddy likes!!!
Very nice and thanks for the note.
What a sick Z! Sounds absolutely crazy!
Thanks - time to order

[Can'tHave2MuchHP]

Updated the main post with some information on the Corsa exhausts.

[BMWM.D.]

Originally Posted by Can'tHave2MuchHP

What counts as high HP? There are lots of 5th gen ZL1s running stock cat-backs with 650-800 RWHP. There's also tons of C6Zs with stock axle backs which are 2.5". Lots of people with stock muffler CTS-Vs which are 2.5". All of these cars when modded are 600 RWHP or more. I have a buddy with a ZR1 that's 850 RWHP with stock axle back. All in all, most people put axle backs on if they want a different sound. A majority of restriction happens in the Headers/collectors/cats/X. Could you pick up power with 3.00" instead of 2.75"? Probably but how worth it is it and how much?

For what it’s worth, the C6 ZR1 is a full 3” system right until the muffler inlets on the case. It necks down to 2.5” there. I still consider it a 3” exhaust. I’ve seen a bunch of data that suggests exhaust diameter becomes far less critical as it gets further away from the engine. As the gasses cool, a smaller diameter pipe can be adequate.

That said, I agree that 2.5” exhaust isn’t the power killer many think. I didn’t really see any difference switching from 2.5” to 3” over-axle tailpipes and mufflers at 700 RWHP. Maybe if I’d had a 2.5” X pipe there would have been more of a difference? I dunno, but I think our 2.75” should support some power.

[Can'tHave2MuchHP]

Originally Posted by BMWM.D.

For what it’s worth, the C6 ZR1 is a full 3” system right until the muffler inlets on the case. It necks down to 2.5” there. I still consider it a 3” exhaust. I’ve seen a bunch of data that suggests exhaust diameter becomes far less critical as it gets further away from the engine. As the gasses cool, a smaller diameter pipe can be adequate.

That said, I agree that 2.5” exhaust isn’t the power killer many think. I didn’t really see any difference switching from 2.5” to 3” over-axle tailpipes and mufflers at 700 RWHP. Maybe if I’d had a 2.5” X pipe there would have been more of a difference? I dunno, but I think our 2.75” should support some power.

Right and that's more or less my point. If I was building a car that I was after every single last RWHP, I'd want full 3" or 4" even. But in most cases, a 2.75" axle back is NOT going to be a limiting factor. In fact, it probably would never be a limiting factor when compared to a 3" system, because like I said, you're talking maybe 20 HP on a 800+ HP car. And it's absolutely true the further you get from the exhaust ports of the engine, the less it matters. That's why it's perfectly OK to run stock axle backs on pretty much every modern performance car I know of. Stock cat-back, different story as most do have pretty poor flow performance threw the X. But that's not the case with the 6th ZL1. Though the pinches, welds, and crushed section may not be pretty, it works and was actually thought out and engineered.

Also the info was bad in the original discussion, the Corsa X pipe is in fact 3" and only goes to 2.75" at the start of the axle back well behind the Diff.

[Rlhay2]

Originally Posted by BMWM.D.

I’ve seen a bunch of data that suggests exhaust diameter becomes far less critical as it gets further away from the engine. As the gasses cool, a smaller diameter pipe can be adequate.

This is Boyle's Law for ideal (and non ideal) gases. The closer a gas is to a heat source (an engine in this case) the more critical volume or space is to the gas.



Why I am not concerned about the "crushed" pipes or the stock suitcase.

[mlee]

Originally Posted by Rlhay2

This is Boyle's Law for ideal (and non ideal) gases. The closer a gas is to a heat source (an engine in this case) the more critical volume or space is to the gas.



Why I am not concerned about the "crushed" pipes or the stock suitcase.

Someone works in the oil patch... just a guess

[Fredtp]

Dose the Corsa x pipe delete the secondary cats like the Borla 60606 x pipe?