Ive read here and there that on 997S's, replacing the stock cats with the high flow ones results in the most power gain from the rest of the mods.

I was just wondering if they would be as much of a benifit to my car since i have muffler bypass pipes, would that be too free flowing and result in a loss of power?

 

It would certainly make power as the restriction in the exhaust is the cats. However, I think you'd be in for a huge shock in the loudness department. Fitting free-flow cats will nearly double the percieved loudness level (and the bypass pipes are err..... not exactly quiet to start with)! I doubt there'd be an unbroken window within a city-block's radius when you cold-started the car.

Ian

 

+1 I needed to de tune my system. The full setup was too loud for my family as well as a few of the local tracks on DE's. I would not have kept the system on my car if I could not have the Cats, a huge difference in the way the car pulled with the cats then with out them.

 

I really love the sound of my car right now but i was afraid of it gettting louder, I was thinking about adding back some mufflers if i were to get the highflow cats on but was not to sure on what kind of sound I would get, plus i would be adding back around 40 + lb's on the car.

 

What's up big guy...I put my fabspeed muffler bypass on my car which has the 200cpi AWE cats and I got pulled over for excessive noise. I just did it for ****t and giggles as I planned on putting the mufflers back on just wanted to try it out. I didn't have the MBP's on for more than a day and I got a fix it ticket.

I will say this though...it sounded like a cup car..it was loud and proud. I heard a 997 with the MBP's and it was awesome..even more so with the cats.

Dave

 

Ian