Just how restrictive are stock mufflers ?

[Offaxis]

I have a twin turbo 2014 with a x-pipe but everything is stock after that. I'm just wondering if that's a major restriction and has anyone with forced induction made the switch to aftermarket exhaust and what gains you are seeing. I'm making 650-700 right now

 

[paulyboy928]

I would imagine you'd see some decent gains if you got rid of the resonators and mufflers being a turbo car. could be wrong though.

 

[Facepuke]

Ive had my car dynoed stock and with the muffler delete. It added about 7hp

 

[Offaxis]

Ive had my car dynoed stock and with the muffler delete. It added about 7hp

Are you forced induction ? What power range are you making

 

[Facepuke]

This was when I was stock, the only modification was the muffler delete

 

[Offaxis]

Nice gains

 

[Facepuke]

Haha I was removing them before I went FI and was just curious

 

[Sleipnir 5O]

Ive had my car dynoed stock and with the muffler delete. It added about 7hp

Same day, same dyno and everything else the same? I find it hard to believe the oem mufflers are that restrictive.

 

[weemon2k2]

I have a Paxton with a 3.6" pulley, cai, Long tubes, o/r X & stock axle back. I should be around 10 psi, but I peak at 11.8. Don't know for sure, but I attribute the higher boost to the restrictive mufflers. 622/511 on 93 octane

 

[rhite95]

A friend of mine has gone 10.48 @ 132+ stock manifolds with Off road x and stock mufflers. The car makes 600 + to the wheels. VMP TVS 82mm pulley...