Gundo

have the same headers, and with AWE cats + PSE, the car comes alive. Literally.

OCBen

Is this another one of those subjective perceptions?

The exhaust header should never restrict the flow of exhaust gases from the exhaust ports, and that's what would happen if the header inside diameter is smaller than the exhaust port inside diameter. In fact, in typical header design, the tube inside diameter is deliberately made larger to reduce a phenomenon known as reversion which refers to the backflow of exhaust gases back up to the combustion chamber.

It may just be my perception but it looks like the diameter of your header tubes in the lower photo is larger than the diameter of the stock ones, assuming similar wall thickness.

http://www.custom-car.us/exhaust/header.aspx

http://www.headerdesign.com/extras/design.asp

Edgy01

I think you misunderstood my comment. the X51 headers ARE larger in diameter than the stock 3.8 headers,--and thus the reason for some torque loss. I was referring to the diameter of the HEADS ports--not the headers.

OCBen

I'm limited in my understanding by what you actually put in writing.

And you wrote that "the exhaust ports on the heads are larger in diameter than the header diameters."

I don't believe the failure to communicate was on the receiving end.

Edgy01

Ben--perhaps it's subjective, but it sure seems that the heads are smaller. I think I might have even mic'ed them but I just can't recall.

larrytrk

I also love the sound with PSE! Deeper and throatier with the headers!!

BobbyB

Dan, if you are losing some low end torque, what is the reason for installing X51 headers?