Exhuast Sizes

[kurbkilla]

So I'm looking at exhausts and are there any 2.5" (65mm) interior diameter piping? Most of the stuff I have found says 2.5" piping but that is the outer diameter, the inter dimension is 2.3" (60mm)

Would 2.3" work for 250whp, 200wtq; or would it tax the system? Any help would be appreciated. Thanks

[Basket Case]

Are you going fi?

[kurbkilla]

Originally Posted by Basket Case

Are you going fi?

Yes ether the vortech or Jackson racing supercharger.

[reardrv]

It would certainly work just fine, going with a 3 inch system you would see a bit more power. Since you're going with a supercharger over a turbocharger a 3 inch is going to be pretty loud. I guess it depends on if you care about the extra horsepower more than the extra noise.

[kurbkilla]

That is why I have a power goal of 250whp. Noise is more important then power.

[reardrv]

I'd go for the 2.5" in your case then. You should be able to hit your power goal with 2.5" just fine without killing your ear drums.

[Dephective]

All setups that say 2.5" is going to be based off the outer diameter of the pipe. The thickness of the wall varies, so inner diameter is not going to be quite 2.5".

In regards to to which you should get, 2.5" is enough to flow with a SC setup just fine at that power level. I hope you mean full exhaust and not just a catback. Catback will do virtually nothing, you need the restriction closest to the motor removed.

[kurbkilla]

Originally Posted by Dephective

All setups that say 2.5" is going to be based off the outer diameter of the pipe. The thickness of the wall varies, so inner diameter is not going to be quite 2.5".

That is what I mean. People talk about a 2.5" exhaust but it is not; the stock ID is 54mm (2.1") and what I was looking at was ID 60mm (2.3") but it is classified as a 2.5" exhaust because of the OD. So is there any 2.5" ID exhaust options out yet?

Originally Posted by Dephective

In regards to to which you should get, 2.5" is enough to flow with a SC setup just fine at that power level. I hope you mean full exhaust and not just a catback.

Since I saw that invidia release a 60mm overpipe I was thinking of that with invidia catted front pipe and the invidia Q300. I was thinking of the ft86 catted UEL header until I get the SC, and then ether the DC Sport EL or the HKS El header.

[Dephective]

the only one that isn't a full 3" OD i've seen is the T1R catback. it's 70mm OD.

[FR-S Matt]

So that's why Invidia states everything is 60mm. I didn't realize for the longest time it was always measured on outside pipe diameter. Makes sense now that the inside is 60mm.

[deletedbilly]

Hi kurbkilla,
All exhaust piping is measured in OD and the wall thickness of the pipe isn’t significant enough to limit the power. For instance, our Borla exhaust uses a single 2.5” pipe that splits into dual 2” pipes. We found the best performance and sound using this sizing, up to and including the SEMA project car we worked on with Vortech Superchargers, obviously sporting their forced induction kit. Below I posted a link to our website with the exhaust for your FR-S. If you have any questions, please feel free to give us a call at 805-896-8600. Happy motoring!
http://www.borla.com/products/frs_br...t__140496.html


Lindsay Lombardo
805-986-8600
Borla Exhaust
www.borla.com