Best Exhaust for turbo application - Page 2 - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

bimmerboy · 09-18-2012, 02:12 PM

for FI you will want the straightest, most free-flowing exhaust out there, preferably 3" in diameter.. Freed engineerings exhaust looks like the best as of yet, as well as the SRT catback.

Also to people who say a certain diameter exhaust is not a restriction, you never know what HP you can gain until you actually switch to a larger diameter exhaust.. So when xxxx tuner says 2.5" is not a restriction, that's just because they haven't tested a 3" back to back.. To my knowledge there isn't a 3" exhaust out yet for this car, feel free to prove me wrong if I missed it..

Again this is all related to a turbo FA20..

xxscaxx · 09-18-2012, 03:51 PM

^ agreed. Also the SP elite is an axleback. Though I agree it sounds good, I don't think it should be mentioned here.

The stock exhaust might not be a restriction but like bimmerboy said, that doesn't mean there aren't gains to be had with a more free flowing and bigger exhaust. I'll be picking up the evo3 and i'm hoping it won't be too loud lol

Entropy · 09-18-2012, 04:02 PM

3" straight-through style is best. Those single inlet dual opposite outlet mufflers are no good for turbo.

This:
–>=||||||||||=–>

Not This:
–>=||||||||||
<–=||||||||||=–>

Tansey86 · 09-18-2012, 04:08 PM

Me personally, I would buy a single exit muffler that I thought sounded good, then go to a exhaust shop and have them make the straightest 3" piping from the turbo to the muffler.

WolfsFang · 09-18-2012, 05:01 PM

if your running no more then 10psi i would go with a 2.5" turboback exhaust.

Coheed · 09-19-2012, 11:41 AM

For turbo, the best exhaust is NO exhaust (figuratively speaking). Make it as short as possible, with proper diameter piping. The turbo spools based on a pressure differential between volute pressure and outlet pressure. So 3" systems will give better response and quicker spool than a comparable 2.5" setup.

But there are compromises we all make concerning sound, emissions legality, safety etc. I would go full 3" on a turbo. It won't be quiet, but with the right muffler setup it won't be too bad. The turbo soaks up a lot of noise as well. Bonus of having a turbo.

Ravenlokk · 09-19-2012, 12:37 PM

2.5 should be sufficient. But ultimately i'd like to run a 3>2.5 bellmouth off the turbo to at least the overpipe.

TyperRspec789 · 09-19-2012, 01:05 PM

Quote:

Originally Posted by ngabdala

+100000000000. Finally someone else agrees with me on 3"

^ that's what she said... Sorry couldn't resist

ngabdala · 09-19-2012, 01:30 PM

LMAOOOO

Quote:

Originally Posted by TyperRspec789

^ that's what she said... Sorry couldn't resist

Ravenlokk · 09-19-2012, 06:57 PM

I just heard that there's a good vendor on this site that may be working on a 3" exhaust for the frs in the future, but they're just waiting to see how the turbo options on the market are when they hit production stages.

Also, if they aren't impressed or comfortable working with the kits as designed, they may develop a kit of their own. And i'm sure it would be beautiful!

I'll leave it up to them to make any sort of official post about it though... All i know is that i'm not going to rush into buying a overpipe/downpipe, or midpipe anytime soon!

09-18-2012, 05:01 PM	#19
WolfsFang Scrape Master Join Date: Jun 2012 Drives: Goal: Oldest FRS State Side Location: North NJ Posts: 1,161 Thanks: 238 Thanked 412 Times in 238 Posts Mentioned: 10 Post(s)	if your running no more then 10psi i would go with a 2.5" turboback exhaust. __________________ You do realize comparing the BRZ to the FR-S is like comparing which hand you love masterbating too right?

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09-18-2012, 02:12 PM	#15
bimmerboy Senior Member Join Date: Mar 2012 Drives: 2009 135i Location: Midwest Posts: 283 Thanks: 126 Thanked 74 Times in 43 Posts Mentioned: 0 Post(s)	for FI you will want the straightest, most free-flowing exhaust out there, preferably 3" in diameter.. Freed engineerings exhaust looks like the best as of yet, as well as the SRT catback. Also to people who say a certain diameter exhaust is not a restriction, you never know what HP you can gain until you actually switch to a larger diameter exhaust.. So when xxxx tuner says 2.5" is not a restriction, that's just because they haven't tested a 3" back to back.. To my knowledge there isn't a 3" exhaust out yet for this car, feel free to prove me wrong if I missed it.. Again this is all related to a turbo FA20..

09-18-2012, 03:51 PM	#16
xxscaxx Senior Member Join Date: Jul 2012 Drives: 2013 SWP BRZ Location: New York Posts: 2,240 Thanks: 458 Thanked 878 Times in 556 Posts Mentioned: 34 Post(s)	^ agreed. Also the SP elite is an axleback. Though I agree it sounds good, I don't think it should be mentioned here. The stock exhaust might not be a restriction but like bimmerboy said, that doesn't mean there aren't gains to be had with a more free flowing and bigger exhaust. I'll be picking up the evo3 and i'm hoping it won't be too loud lol

09-18-2012, 04:02 PM	#17
Entropy Oversteer > Understeer Join Date: Jul 2012 Drives: GT86 Location: PDX Posts: 87 Thanks: 17 Thanked 40 Times in 17 Posts Mentioned: 1 Post(s)	3" straight-through style is best. Those single inlet dual opposite outlet mufflers are no good for turbo. This: –>=\|\|\|\|\|\|\|\|\|\|=–> Not This: –>=\|\|\|\|\|\|\|\|\|\| <–=\|\|\|\|\|\|\|\|\|\|=–>

09-18-2012, 04:08 PM	#18
Tansey86 Senior Member Join Date: Sep 2012 Drives: 2003 Subaru Outback Location: Long Island, NY Posts: 1,318 Thanks: 154 Thanked 529 Times in 300 Posts Mentioned: 3 Post(s)	Me personally, I would buy a single exit muffler that I thought sounded good, then go to a exhaust shop and have them make the straightest 3" piping from the turbo to the muffler.

09-19-2012, 11:41 AM	#20
Coheed Senior Member Join Date: Jun 2012 Drives: DGM BRZ Limited Location: Seattle Posts: 813 Thanks: 209 Thanked 225 Times in 157 Posts Mentioned: 1 Post(s)	For turbo, the best exhaust is NO exhaust (figuratively speaking). Make it as short as possible, with proper diameter piping. The turbo spools based on a pressure differential between volute pressure and outlet pressure. So 3" systems will give better response and quicker spool than a comparable 2.5" setup. But there are compromises we all make concerning sound, emissions legality, safety etc. I would go full 3" on a turbo. It won't be quiet, but with the right muffler setup it won't be too bad. The turbo soaks up a lot of noise as well. Bonus of having a turbo.

09-19-2012, 12:37 PM	#21
Ravenlokk Senior Member Join Date: Aug 2012 Drives: 2013 Raven FR-S Location: Vancouver, Canada Posts: 265 Thanks: 34 Thanked 68 Times in 47 Posts Mentioned: 0 Post(s)	2.5 should be sufficient. But ultimately i'd like to run a 3>2.5 bellmouth off the turbo to at least the overpipe.

09-19-2012, 06:57 PM	#24
Ravenlokk Senior Member Join Date: Aug 2012 Drives: 2013 Raven FR-S Location: Vancouver, Canada Posts: 265 Thanks: 34 Thanked 68 Times in 47 Posts Mentioned: 0 Post(s)	I just heard that there's a good vendor on this site that may be working on a 3" exhaust for the frs in the future, but they're just waiting to see how the turbo options on the market are when they hit production stages. Also, if they aren't impressed or comfortable working with the kits as designed, they may develop a kit of their own. And i'm sure it would be beautiful! I'll leave it up to them to make any sort of official post about it though... All i know is that i'm not going to rush into buying a overpipe/downpipe, or midpipe anytime soon!

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