Cats or Not?
 

hey all i am going to be buying a Xpipe sometime soon here and wanted to know what your thoughts are on if i should go with the offroad or the Cat version.... i do plan on adding a supercharger soon also.... and i know that SC/Turbo 4bangers tend to preform better with out Cats is the 4.6 the same way?
also what are some of the pros/cons of either setup aside from inspection and a sniffer

Umm I see no reason to not run cats. The loss of any power with todays cats is so small.

the hp diff. is pretty minimal. if you want your car loud go no cats, if you want to keep the decibals down some get the cats. also you will need mil eliminators or a aftermarket chip so your check engine light doesn't come on if you don't have cats! with cats no problem. fyi. good luck.
Leon

I went with No-Cats for the simple reason of COST. Its like 150+ dollars less with no cats.

Tim C and I built our own MIL eliminators. The Flotech cost me 112$, with cats I think it was 259$. MIL eliminators usually run around 50-60 dollars. The parts to build one ran me 6$ at Radio Shack. I had to go to 4 stores though to get the 4 main parts neccassary.

Hey Mercury do you mind posting on how you built your own eliminators? Thanks

Just an opinion:
With cats, retain your low end torque and gain mid range HP... Without cats, lose low end torque and gain upper range HP.
I went with cats...4.6's already lack in the low end torque department.

Umm not exactly. With an Offroad H I picked up low end torque and power throughout the power band. An Offroad X will lose a little low end torque and will gain 1-2 more RWHP than an H.

Bill

Umm, I thought he said an X-pipe specifically...

Would'nt you say an X-pipe paired with a 9:1-9:4 compression ratio will fair better with some back pressure. On the other side, a 10:1-11:1 compression ratio fairs better with no back pressure...in reference to low end torque...

Cliff

hey thanks for the input guys! i think i am gonna go with a Xpipe with cats.

I didn't catch that part sorry about that.

Honestly I don't have enough experience personally with the X pipe because I don't care for the sound. However when I change over to Longtubes I'm going with an offroad X and bullet mufflers and from what I've seen on the dyno there will not be a loss in power due to a lack in back pressure.

Bill

I'll chime in here. I've had both since my Bassani X with cats failed. I liked the Bassani with cats but the cats are junk and eventually fail as many Bassani owners have found out. If you want cats, go with VRS. I think they are not only cheaper but better made.

On the power issue.. I've heard from anyone who has gutted or replaced their cats, that torque goes up, despite the butt-o-meter feel of loss. I think the reason why it feels like we lose torque is because power increases nicely on top to make it seem like we lose some down low. I know the back pressure idea makes sense though. Once I get my car's O2 sensors replaced, I'll kknow for sure on my car.