I'm getting a custom built Xpipe exhaust done for me right away here.

The questions is.... should I do 100 cell cats? or just go catless??

How much power would I be sacrificing going with 100 cell cats? I'm just worried about the car being so loud that I can't drive it....

 

No emission testing where you live?

 

I just had to make the same decision and went with cats. It wasn't worth a few HP to deal with and smell or emission testing. Guys on here have said you don't get the fuel smell on these cars, but I didn't want to take a chance.

Look how nice they look too.

 

No emissions up where I am.

100 cell will get rid of the smell?

 

Some say the car will have a sour gassy smell if your sitting at a light or in a garage without cats.
I can 100% agree with this if it's on an evo or sti.
The 996tt is fine though no problems in that area.

 

I am going to take the cats out of FVD once i figure out my trans issue fwiw.....

My B5 s4 hs not had cats in it since 03 ish, That car does have a bit of a smell, but i do not daily either of them....

 

I'm not sure I agree with your logic on this. Someone without cats needs to post.

 

Isn't that great, now if we did not have 6 months of winter, 9 months of gravel on roads and we still had a race track life would be extra grand!!!!!

 

I have 3" xpipe with no cats, loud but not crazy. Doesnt smell at all, will be installing cats though to cut down on the noise and to save the world.

 

Race City was ****, something much better is in the works.

 

I did have no cats on a gutted stock system. I cut it open and removed all four cats and welded it up. You won't have any issues with a 996tt.

 

Did you have an ECU flash done also?

 

3" catless X-Pipe...Aggressive and not TOO LOUD

 

HI,I hate to throw in this in But then there is a difference in flow depending on the over all cat size,bigger is better......Not to many people address this...There are articles about this from HJS,Europipe,Milltek and that tuner Kevin from UMW brings that up on his Rennlist posts....
Does the cat size,surface area, really make that big of a difference???You have to decide that,as you have to decide between the difference of 100 verse no cats..I personally dont like the smell when the car is started cold and ran until it is warmed up...To each his own....Good Luck..

 

I have straight, Fabspeed cat less pipes for the track. It sounds like a bomb going off at cold start up. It is obnoxiously loud. NOT recommended AT ALL for driving around town. When I drive to the track and back, people on the street are visible startled when I drive by. I also used the pipes on my 24/18g car and they were nearly as loud as well on that car. But with my new GT35 turbos car, its simply ridiculous. I have to wear earplugs.

The videos posted by MannschaftQ8 showing the x-pipe without cats sound nothing like straight pipes. They sound great actually.