High Hp 600+ exhaust systems

bracer · 10-19-2019, 10:46 PM

So I'm wondering if on the high HP 600+ whp cars out in the wild now if we think the dual 2.5" exhaust / 3.5" single exhaust systems are enough?
I know there has been testing in the past on different cars and we're definitely past where dual 2.5" exhausts are efficient at least on those cars. Has anyone tested a true dual 3" system or a 4" system? Were there any improvements?

Kev608 · 10-20-2019, 09:28 AM

For a turbo charged car, you want upstream pressure to be high and downstream pressure to be as low as possible. You definitely would see a gain from a dual 3" system. Gintani is the only offering I'm aware of. Dual 3.5" would be best, but I don't believe anybody is making one. Fitting it to our car would be rather hard, since the current offerings already have a hard time fitting the space available.

Edit: perhaps consider adding cutouts after the DPs? This would greatly reduce back pressure as needed.

Shadow2 · 10-20-2019, 11:48 AM

AWE makes a full 3" system from the downpipes back, thats what I switched to coming from the typical AA midpipe, stock muffler, when I put on Pure st2+ turbos a few months back. I think they are the only ones making one that large. It sounds incredible, but its hard to gauge any actual HP improvements because I'm still in the process of tuning and dialing in the setup, not done with the fueling side either yet. There are a few online calculators out there, showing the larger dia pipe is definitely needed as you up the HP levels. One I found says dual 2.5" pipes support up to 463hp, dual 3" can support up to 679hp. Keep in mind there are a lot of variables involved here, exhaust gas temp, fuel, intake volume etc... All made more complicated by the fact these are turbo cars and not NA motors.

10-19-2019, 10:46 PM	#1
bracer Mr Bill 296 Rep 545 Posts Drives: GLC63 Join Date: Sep 2013 Location: Aliso Viejo iTrader: (1)	High Hp 600+ exhaust systems So I'm wondering if on the high HP 600+ whp cars out in the wild now if we think the dual 2.5" exhaust / 3.5" single exhaust systems are enough? I know there has been testing in the past on different cars and we're definitely past where dual 2.5" exhausts are efficient at least on those cars. Has anyone tested a true dual 3" system or a 4" system? Were there any improvements? __________________ 2018 GLC63 2016 Miata 2020 X3M (sold) Turbo Miata Racecar (sold) 1995, 2009, 2015 M3 (sold) Last edited by bracer; 10-20-2019 at 06:03 PM..
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10-20-2019, 09:28 AM	#2
Kev608 First Lieutenant 171 Rep 310 Posts Drives: M4 Competition Join Date: Oct 2019 Location: Madison, WI iTrader: (0)	For a turbo charged car, you want upstream pressure to be high and downstream pressure to be as low as possible. You definitely would see a gain from a dual 3" system. Gintani is the only offering I'm aware of. Dual 3.5" would be best, but I don't believe anybody is making one. Fitting it to our car would be rather hard, since the current offerings already have a hard time fitting the space available. Edit: perhaps consider adding cutouts after the DPs? This would greatly reduce back pressure as needed. Last edited by Kev608; 10-20-2019 at 10:36 AM..
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10-20-2019, 11:48 AM	#3
Shadow2 Second Lieutenant 121 Rep 254 Posts Drives: '16 MG F80 M3 Join Date: Dec 2018 Location: DMV iTrader: (0)	AWE makes a full 3" system from the downpipes back, thats what I switched to coming from the typical AA midpipe, stock muffler, when I put on Pure st2+ turbos a few months back. I think they are the only ones making one that large. It sounds incredible, but its hard to gauge any actual HP improvements because I'm still in the process of tuning and dialing in the setup, not done with the fueling side either yet. There are a few online calculators out there, showing the larger dia pipe is definitely needed as you up the HP levels. One I found says dual 2.5" pipes support up to 463hp, dual 3" can support up to 679hp. Keep in mind there are a lot of variables involved here, exhaust gas temp, fuel, intake volume etc... All made more complicated by the fact these are turbo cars and not NA motors.
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