exhaust sizes

[Geoff Green]

I have a question regarding header and exhaust dimensions. The square inches on a 3" exhaust on each side is 7.065. If you increase your headers to 1.75" your total square inches on each side is 12.0203 squares inches. It seems that you are restricted by your 3" exhaust. If you have 1.625" headers your total inches is still 10.3645 trying o exit a 7.065 exhaust. With a 1.5" header you still have 8.83 square inches. I can see changing out the cats and back because you only have 4.9063 square inches on a stock 2.5" exhaust. Is there really any gain in changing headers on Gen 2? Geoff Green

 

[99 R/T 10]

Keep in mind that the cylinders don't all hit at the same time, so you won't max out the volume at anytime unless you're pumping a heck of a lot of air(turbo/SC). The 96-99 cars gain a fair amount with changing exhaust mainly due to the 708 cam that is used. The "creampuff" cars have a milder cam(diff overlap) that shows only a little improvement with the change.

 

[Geoff Green]

I have a 98 GTS and it seems that the biggest gain by far would be to swap out the cats and back. I don't know how much would be gained with the 1.75" headers. I guess if I ever supercharge the larger headers would pay off. I have gone back and forth on this for some time and would like to do it this winter. I just have to decide. One choice would make it easier.

 

[99 R/T 10]

How about a set of 1 3/4" headers for $1500 shipped? B&B or Powerflows? Check the classified for my ad