I just snipped this from the "Buschur Flashed" thread and thought it made more sense as a separate thread. I am dumbfounded by this statement. Is this a dyno proven difference? I thought that a high flow cat was within 5-10 whp of a test pipe, if not less, especially at pump gas boost levels. Since this is coming from a source that a lot of people trust, I thought this was worth a little discussion.

Thanks.

 

This is of course with a lot of different mods to go along with it. For exmaple, a full 3 in exhaust that could give a stock motor around +15whp can give a motor w an aftermarket turbo and cams at least 25-30whp.

 

Right, but this wasn't being discussed in the context of a 400+ whp application. We're talking about running 20 psi with the stock turbo here -- the power range that many of our cars are in.

 

We tested a test pipe on the dyno and immediately it added 15whp. The evo had 300 whp.

 

Was this on a car with a 3" turboback and a 3" high flow cat before you put on the test pipe?

 

dude just get the test pipe youll like it.enough said.

 

the car had a thermal r&d catback, hks 2.65" downpipe. Once the TP was added we had instant 14 - 15 whp.

In CA you cant have a test pipe. You get caught, bam, $1500 fine + 30 day impound if they dont like you @ $30 a day. That doesnt mean people dont use em...like myself. Not anymore right now. Got scared to death by a cop so I took it out immediately.

 

I know you cant in Cali, but no use not having one to put on occassionaly, or even risk the chances.hehe. Luckily here we dont even have emissions laws

 

How about those new high flow cats?

Someone should design a test pipe that looks like a cat on the outside,those would be a hot seller in CALI...

 

I have never known Random Tech cats to hold back 15 hp...

 

Gotcha. Stock cat vs. test pipe. I can believe the power gain there. What I'm skeptical about is a 3" high flow cat eating 15 whp in the mid 300 whp range. Maybe the Vishnu 3" cats are as restrictive as stock

 

On a 400hp turbo car, even the best free-flow 3" cat from Carsound, Random, etc, will be restrictive. We've tested a few metallic core cats which were slightly less restrictive but they offered decreased catalyist performance according to the sniffer.

my 2c,
shiv

 

Just knock the matrix out of the cat, WHAMO, you got what your talking about. It wont flow as well as a test pipe, but it will definetely outflow an operable cat. If you were to get pulled over, the cop would see a cat in place. I doubt the cop is going to put your car on jack stands, remove the cat to physically inspect the core.

I had heard from a 5.0 nut, that they would drill a 1" hole down the center of a cat & still not throw a check light!?!?!?

I dont believe it, let alone I would most likely **** the cat up & end up gutting the thing anyways.

 

WOT, for me that may be a good answer. Here in MD, they have siginificantly relaxed emmissions lately. All they do is plug their computer into your OBDII port and look for codes. No codes, and off you go. However,they have the right to use the mirror under your car to look for the cat. They don't always do it, but you never know. A hollow cat would solve that problem.....