WalleyRuss

Hey everybody. I would like a few opinions here. I have a 4" MBRP exhaust on my 2011 Ecoboost with the 3" Livernois offroad downpipes and tune. I have been hearing rumors and have read in a few places that this 4" exhaust is overkill and that I might be making less power than I could with a smaller exhaust. This goes against everything I've previously been led to believe; with turbo's the less back pressure the better. I don't want to have something on my truck that is gonna make less power than it should.

So here is my question; If I were to add a 3" resonator into my 4" exhaust would it help me gain some of that back pressure back and therefore gain back some of my power/responsivness?

Thanks in advance for your opinions!

scross86

http://www.exhaustvideos.com/faq/how-to-calculate-muffler-size-pipe-diameter/

Worth a read, and while yes the 4 inch exhaust may seem like overkill to some. The restriction your turbos are creating likely give you all the exhaust velocity you need. Restriction is not something you want however exhaust velocity is for throttle response. The balance is key there. If you dont feel and lag in getting on the gas beyond the millisecond of turbo lag then you should be good. However it is also my understanding that thr y pipe meets into a 3 inch pipe before your 4 inch exhaust setup, so really your truck is understanding your turbo back configuration to be that of a single 3 inch pipe.