askkmb

iTrader: (2)

Hello, i just installed a whipple 2.9 on a 2017 sierra with a 5.3. Currently running 10 psi and i feel like it isn't as fast as it should be on 10 psi. Need to get it on the dyno to confirm with numbers. The truck is 100% stock besides the whipple and a custom tune by myself. So i am thinking the exhaust might be what is restricting me right now. How much do you guys think would it gain from having a set of headers installed and a 3.5" exhaust? And what muffler would you recommend to be as quiet as possible without restricting it?

FFDP

iTrader: (2)

With doing nothing else but just headers, I'd guess at under 30hp gain.

The factory 3in exhaust is good for a lot of power, swapping to 3.5 woudln't help you any.