Yeah but could you stand the rasp for the few hp gains? If one could gut and then weld in some straight pipes inside to make function like TPs, that might work.

 

If you truely have an '08, then please trade it back in. Anyone who is ignorant enough to even consider hacking up the cats on a brand new car doesn't deserve it.

 

Doesn't anyone actually read the thread anymore? He has an extra set of cats to gut and wants to look stock. What a ricer, he wants to look stock and gain power.

Sorry I can't help you out with before and after dyno plots. I would go for it though, you don't have much to lose. As far as the rasp, I doubt there will be any with a stock G35 sedan exhaust.

 

Despite some good points being made based on exhaust theory, what anyone can tell you at this point is just speculation. Due to the restrictive nature of the stock cats, better than older OEM cats, but still fairly restrictive, by removing all the innards you're going to gain CFM thats a given. CFM alone won't determine the effects on exhaust velocity, but it will flow better in the upper RPMs. I'd venture a guess and say you'd gain about the same numbers as test pipes above 5000 rpm. Below 5000 rpm, worst case scenario you lose a little bit of torque, best case scenario you don't. Even if you lose the low end, the overall result is going to be a faster car if thats the goal you're aiming for. If you already have the extra set of cats acquired for cheap, what have you got to lose?

TK

 

Anyone:

Send me your gutted cats and I'll trade you a set of strup test pipes for them.

I will dyno the gutted cats against regular test pipes. Same day, same everything.

 

cant beat a deal like that

 

Is it worth the noise though. Those hollow cans have to be resonating monstors when gutted.

 

Rice eh? I looked at your signature and seen "Coming soon: Nismo license plate frame"


If you have an extra set. You don't have anything to lose. Sure they cost soo much from the dealership. But on the board you will find them for MUCH LESS then that. Hell, I got mines for 60shipped.

Personally, I would rather have gutted cats. There more durable then most aftermarket brands. Keeps your car "stock", giving you less hassle from the cops and inspection. Also, its free. Just takes alittle time.

Yea, there not straight through design, but is it really gonna effect it THAT much. Would you say to buy an X brand TP to only gain a small amount of power over gutted cats? But in return you do lose the factors I stated earlier of gutted cats.


I guess its down to personal preference. Some people say "why don't you just buy TP,HFC,etc..."
I say why do that when you can gut your cats, and save some money for bigger mods.

 

The thin walls of the OEM cat housing will be freaking loud. The cat material serves as a muffler. Without it, the noise will be nasty.