What is the stock oem headers outlet size?

[clb0099]

The aftermarket headers are 2.25, what is the stock headers opening size? If i got this correct the oem 2" in/out so that means .5" difference, is there much of a different in sound? I am not worried about horsepower gains cause i am supercharging my car . I have the aftermarket pse mod, so there is good sound but just want to know if this increase the sound much more? One more question I have headers from my 1997 boxster 2.5L , I am wondering if I can use them for my 2002 996 c2?

Edited August 19, 2011 by clb0099

[therock88]

The aftermarket headers are 2.25, what is the stock headers opening size? If i got this correct the oem 2" in/out so that means .5" difference, is there much of a different in sound? I am not worried about horsepower gains cause i am supercharging my car . I have the aftermarket pse mod, so there is good sound but just want to know if this increase the sound much more? One more question I have headers from my 1997 boxster 2.5L , I am wondering if I can use them for my 2002 996 c2?

Sounds like you got the opening sizes about right. The horsepower gain from additional outflow could be slight. The sound change would likely be negligible if at all. Does not appear you can use headers for a 2.5L Boxster engine, on a 3.4L 996 engine. Totally different engines and configuration of exhaust. Part numbers and diagrams attached.

Good luck.

DC

Edited August 19, 2011 by therock88

[JFP in PA]

One point often overlooked on header pipe and collector sizes is the fact that you can go too big, which tends to move the torque curve up in the RPM curve, reducing the car's drivability. When the tubes get too big, the velocity of the exhaust gases actually begin to slow down, reducing the lower RPM cylinder scavenging effect, causing the perceived loss of low end response. Don't go nuts, as "size really does matter", and there is a "too big"................

Edited August 19, 2011 by JFP in PA