So I just recently purchased a BBK O/R X Pipe (Catless) off a guy and we are going to install it this week. My question is, with the mods in my Sig, (Catback, CAI, tune and gears) Will the car be gaining some decent HP over stock midpipe? I have heard a small loss in low end torque, but I don't think that will be a problem with 4.10's! Oh and im also getting a 78mm throttle body plenum combo same week so it will help pull more air to help the exhaust make use of it.

 

From a stock mid pipe I would guess 15-20 hp.

 

Unless you go with headers as well. I don't think you'll see that much.

 

I think taking off 4 cats, you'd think there would be a pretty decent gain, I will be doing cams and longtubes in the future, but I was curious to the gain just as is.

 

You will feel a good difference in throttle responce, and how she pulls threw the rpms. I will add though, having at least two hi flow cats added in would be better in aiding in back pressure, and the loss in hp is soooo minimal.

 

So I will be actually losing some hp? Or will it be a loss of HP in the low RPM and gain in the high?

 

No, you will gain hp with this swap.
What i was saying this that if you were to add in aftermarket cat's, you might loose a bit of hp, and i should've finished with that you would maybe gain a few more points in torque doing so cause of the back pressure with them added in.
Either way, you can't go wrong.

 

Awesome! Can't wait! Install this week! I'll do a before and after vid!

 

It will sound like it gained 50 hp lol

 

Oh WOW is all I can say lol! I think its the loudest car in like 100 kms of where I live lol. Just insanity loL!! Picked up some good top end, might have lost some low end tq, not sure but its untuned so it will only get better!