How much hp is x-pipe ONLY on stock cobra?

[Friendchicken]

I didn't have a chance to do a stock dyno, but I am wondering... what gains does my bassani x pipe w/cats give me on an otherwise bone stock cobra?

 

[MidLifeC]

At one of our dyno days, 3 cars with an aftermarket x pipe gained 0-2 more HP and 8-10 more torque than me.

Now, those are peak numbers. We did not compare the whole rpm range.

 

[03'Darin]

I recently saw dyno graphs on two modded cars. Both had cai, 2.93, chip, and cat back. Car one had BBK LT's with an o/r x-pipe and car two had high flow cats (not sure which brand). Both cars even had the same cat back exhaust system. Car one with L/T's and the o/r x-pipe was running almost 1 point leaner on a/f (mid to high 12's) and only pulley 14 rwhp and 11 rwtq more than car two.

I have never seen very big gains posted by anyone from just removing the factory cats.

 

[PhillyCobra]

Changing cats alone has little effect as the stock ones cause much less restriction than the stock headers and cat back system. The only situation in which changing or removing cats seems to significantly help is when you have good headers and cat back system on a highly boosted car.

 

[03'Darin]

Headers don't seem to due much for these cars. Maybe if you are running big boost numbers. But not worth the time and big money for them IMO.