Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB

- Engine, Exhaust, Transmission (https://www.ft86club.com/forums/forumdisplay.php?f=8)

- - Stock catback with turbo (https://www.ft86club.com/forums/showthread.php?t=112776)

Stock catback with turbo

At the moment my exhaust set up is FBM turbo manifold with open dump, 3 inch downpipe, and nameless OP/FP with cat and resonator and a greddy evo 3 exhaust running 8PSI. Ive had this setup for the past 40000 kms.

Im wanting to change back to the stock catback because of the unbearable drone coming from the evo 3 even with the silencers in. I think the drone is also being amplified by the whiteline subframe inserts and diff bushings I put in a couple weeks ago. I did account for the added NVH and would consider myself quite tolerable to it but its gotten to the point where the drone cannot be ignored. I double checked if any part of the exhaust was rubbing against the subframe to ensure that wasnt the cause of the vibrations.

My question is if the exhaust flow will be sufficient with the stock catback exhaust? I know FBM had great success with the stock catback. My priority right now is to eliminate the drone as best I can and reach a tolerable noise level. Thanks for the input.

If your only running 8psi you will be just fine.

It'll be fine, especially since you have an open dump.

Quote:

Originally Posted by yo.dur (Post 2793242)

You'll lose a little bit of spool-up time, but not much; temperature will affect that more than your exhaust.

Your scenario sounds like the perfect candidate for one of the upcoming CSG "Laguna Special" exhausts. The final prototype being tested on the CSG test mule (JRSC, HBP, E85, Ace header, Ace FP), blows all of 87 dB at WOT, at redline, from 30 feet at a 30 degree angle. As a reference, 96dB is considered street legal.

Quote:

Originally Posted by CSG Mike (Post 2793959)

but what about because racecar?!

Thats actually fairly impressive feat in regards of maintaining a similar level of performance of most straight through exhausts.

I've been following that thread.

Quote:

Originally Posted by CSG Mike (Post 2793959)

Blows all of 87 dB at WOT, at redline, from 30 feet at a 30 degree angle. As a reference, 96dB is considered street legal.

That's great news!
Would it be possible to test the exhaust per CCR 1036?
20 inches from the exhaust at a 45 degree angle.

Quote:

Originally Posted by CCR 1036

(b) Microphone Location. The microphone for the sound level meter shall be at the same height as the center of the exhaust outlet. The microphone shall be no closer to the pavement than 8 in. (203mm) when the exhaust outlet is lower than this height. The microphone shall be positioned with its longitudinal axis parallel to the ground, 20 inches plus or minus 1 inch (508mm plus or minus 24mm) from the nearest edge of the exhaust outlet, and 45 degrees plus or minus 10 degrees from the axis of the outlet. For exhaust outlets located under the vehicle body, the microphone shall be located at the specified angle and at least 8 in., (203mm) from the nearest part of the vehicle. For exhaust outlets that make an angle of 45 degree or less with the longitudinal axis of the vehicle, the microphone shall be outboard of the exhaust axis. For exhaust outlet angles of more than 45 degrees, the microphone shall be on the side of the exhaust axis to the rear of the vehicle.

Quote:

Originally Posted by CSG Mike (Post 2793959)

Yeah I put back on my stock exhaust last night, definitely noticed that i lost a bit of spool up time. A fair sacrifice to preserve my hearing.

I stumbled upon that thread a couple days ago and that sounds like the perfect fit. Im looking forward to that being released cause i want to buy it!