I have not hit the dyno yet but I am guess since this exhaust is nice and quite that it is hurting performance. 13brew street ported intake and exhaust. Bw s366 turbo with .91ar exhaust. 4" downpipes into racing beat pre silencer then to the dual mufflers. The car is really nice and comfortable to drive. Just wondering what kind of number people have put down with this exhaust. I might dump the pre silencer and continue the 4" to the duals. I am shooting for 450whp range. Which I don't see that being a problem just wondering if there are anybody putting big numbers with this exhaust.

 

I just put 357 to the wheels on my FC with an RB presilencer and REVII Turbo Catback.
I could have done more but the turbo was showing signs of failure.
(so I think you'd be good).

 

switch out the presilencer to run a straight pipe. you wont be complaining how quiet it is lol

 

I did 360 as well np, 4" down pipe as well......ign break break stopped my climb

It will make the power as long as you have the fuel and ign, the high compression rotors will serve you well

 

427 with RB duels, 3 inch custom downpipe, T04R turbo, 44mm wastegate plumbed back into the exhaust smoothly.

Will you make more power with a less restrictive exhaust? Yeah. Will you overall enjoy driving the car as much without that smooth RB duels sound? Maybe not.