FR-S / BRZ Big 3" Cat Back Exhaust

[DarthThinmints]

http://www.perrinperformance.com/brz...t-back-exhaust


Does anyone have any sound clips for this exhaust yet?
Pros/Cons?

[FT-86 SpeedFactory]

You're going to have to move A LOT of air to need that much exhale... and I mean A LOT for this car.

[FR-S Matt]

I don't think it will be a problem with a tune and header. 3" exhausts are just heavier and work well with turbo applications. You shouldn't have a problem with a 3" NA + a header and tune. You might see some low end loss at real low rpms on a stock tune due to the size, but I'm talking an entire full 3" system. The 3" catback alone won't make a difference from the 2.5". 3" systems also are louder, but even the resonated Perrin is still fairly quiet in my book. Sounds a bit more throaty with the 3" though.

My 3" Nameless axleback doesn't do anything different from the 2.5" because the front half of my exhaust is stock. I just want the 3" in place for when I do get the rest of the 3" portions of the exhaust.

[chadstyle]

With NA and 3" exhaust on this car you will LOSE power. FA20Club built a full 3" system and it lost substantial power. If you go turbo then it will help out but until then don't waste your money.

[Gardus@Supersprint]

76mm on a 200 hp NA car? It will kill the power delivery.
We usually use 76 on cars with well over 300 hp.

65-70mm is enough for 2.0l turbo car under 300 hp.

[FR-S Matt]

Originally Posted by chadstyle

With NA and 3" exhaust on this car you will LOSE power. FA20Club built a full 3" system and it lost substantial power. If you go turbo then it will help out but until then don't waste your money.

Do you have a link to that?

I'd like to see more info on where it kills power. I was considering going 3" to be a placeholder for a bit before I went turbo. If that's the case, I may go 2.5" in front then.

Possible dyno charts?

[DarthThinmints]

Originally Posted by FR-S Matt

Do you have a link to that?

I'd like to see more info on where it kills power. I was considering going 3" to be a placeholder for a bit before I went turbo. If that's the case, I may go 2.5" in front then.

Possible dyno charts?

Dyno charts would be awesome(:

[Marcoscrdo]

^ Been waiting for this info. I will go for the smaller version since buying turbo will take a really long time. But thanks guys. Would still want to see dyno charts of the power loss on a fully stock car..

[frslee]

3" exhaust for this small engine? Even Audi S4 V8 guys run 2.5 and 2.25 at the end.

[Tansey86]

http://www.ft86club.com/forums/showthread.php?t=37542 - Install Thread

[ame="http://www.youtube.com/watch?v=gI1fRwlLI_c"]NWMotiv - Project BRZ - Perrin 3" Exhaust - YouTube[/ame] - Sound clips

Pros:
Room for growth in terms of HP if you decide to go F/I
Louder(if you like that)

Cons:
Louder(if you dont like that)
Less clearance
Heavier

That's the basics of it. Like others have stated, I would suggest a 2.5 exhaust if you plan on staying with bolt ons. If you go F/I 3" hands down is the way to go.

Also, engine size has no bearing on what exhaust size you should run. Its all about power and moving the air out as fast as possible.

[jamesm]

i don't know much about n/a tuning cars (i'm a turbo guy), but i grew up around motorcycle racing and used to tune race bikes for a living. in that arena, it's generally accepted that the higher compression, the more flow you can afford on the exhaust side without losing midrange. of course there's a lot more that goes into building a 1000cc engine to 220whp, but that's a basic principle a lot of people agree with.

you see this in cars as well. k-series honda motors are relatively high compression and see gains with 3" exhaust over 2.5". i'd imagine the same holds true for our even higher compression engines.

in the end, gains from any catback will be negligible, so it's probably a moot point. if you're going turbo, get the 3", if not, get what you thinks sounds good and fits the budget.

[Surfacer]

Originally Posted by Tansey86

Also, engine size has no bearing on what exhaust size you should run. Its all about power and moving the air out as fast as possible.

I've been told that it does. To do with back pressure?

[Tansey86]

Originally Posted by Surfacer

I've been told that it does. To do with back pressure?

Well a naturally aspirated car wants back pressure. A turbo car does not want any back pressure.

That being said, its not the engine size that's making the difference so much as if its all motor or it has some sort of boost application.

[FR-S Matt]

Until someone proves otherwise, I don't see a problem running 3" N/A on this engine, especially if you plan on doing FI in the future.