Race fuel has a great smell to it......

 

XBoth 997 and 991 Cup cars come with catalytic converters from the factory. If you are going to race in any official series like the IMSA GT3 Cup Challenge then you are required to run the full factory exhaust with cats as sold by Porsche. No if ands or buts. Even Motorsports segments are moving towards being more environmental. I think it's only a matter of time when Cats will be mandatory everywhere and violators will potentially face huge fines. Ask someone in Switzerland for example what kind of fine you would face if caught operating a car catless. For 90% of users, with a quality catalyst you are giving up virtually nothing in regards to performance. I suspect the people that see a noticeable difference in performance when going catless are those that go from a relatively small diameter restrictive 200 cell cat instead of high capacity free flowing Motorsport cats. Certainly, not all cats are the same even if they are listed as "100 cel". If your exhaust manufacturer does not tell you what kind of cats are on the exhaust, watch out. Ask what diameter cats they're using. The larger the diameter equals a larger cross section area, which equals greater flow. Insist on big cats for best performance. Most aftermarket exhausts use 100mm or smaller because the're cost effective, functional, and most people don't know the difference. As the saying goes, you get what you pay for. A high end 130mm or 144mm Emitech/HJS Motorsport 100 cell cat will set you back almost $2K for a pair but you will be leaving very little performance on the table. If you live in an area that does not require cats then great, but if you live in one that does, eventually the risk of getting busted, paying a 5 figure fine, and/or risk having your car impounded will outweigh the benefits. Time are changing and not always for the better.. Just my $0.02..

 

So well put and I learned something. Thanks pwdrhound

 

True good points. And many manufacturers including Kline will build it how you want it. But the fact remains that those are sanctioned monitored bodies under certain rules and regulations. Factory cars. Lots of cup race cars do not run cats at the same time in other events and series. Also they are not turbocharged putting 700-1200++hp. Those guys will always make more power without cats and will just not run them unless the hammer really drops. It's a huge part of the Hot Rod/motorsports car culture and nothing new. Times are changing that's true. But there are so many factors to be realized. Cost, tuner request, EGT's, power gains, sound, The infamous two step and more that I'm forgetting.

I run 100cel cats on my car for the street. But on the track they come off.

To each their own. That's why we live in America. And why most exhaust manufactures build modular systems let alone in different sizes for different applications.

 

..and as sam has pointed out, i can go from "scofflaw" to "obedient automaton willing and grateful subservient subject" that obeys all edicts from my loving gov't in about 20 minutes with no one being the wiser for having done so.

or, at least my car can LOL

i'll take that risk. i am after all a card carrying member and early participant of the 50+ year old mulholland racing club and their collective shenanigans. ftw

 

this thread made me realize i need cats. i'm getting 4 installed as week speak.

 

Real test of the 2 step to see if you can blow 4 cats out now

 

good point. just called and requested 6 cats instead of 4.

 

Why stop at 6? If two is good, and four is better, then imagine say 10!

 

fittment issues. i could dual passthru them ...

 

Couldn't you make the exhaust loop to the roof like a diesel stack?

 

Just weld them back to back, I think you could fit about 12 from turbo to bumper

 

cat fix

 

How long could this thread go on with cat jokes?