anyone have any dynos, videos or opinions about gutting cats?

 

Aren't gutted cats and test pipes essentially the same thing ?

 

no, a test pipe is a straight through pipe, a gutted cat has a big open area which could theoretically mess up your exhaust flow by causing turbulence

 

the flow will be different... i would say that you'll get more turbulence when using a gutted cat rather than using a test pipe.

but then again i have nothing to back that up.


edit: dang lol... a few seconds too slow...

 

yeah but no one seems to have a dyno..lol

i mean maybe the test pipe gives u 7whp and the gutted cat gives u 6 or maybe it subtracts hp, someone must have dynoed with gutted cats. i would just go for test pipes, but id rather have oem fitment and if someone were to look they couldn't tell

and before anyone says anything, im not going to gut my cats, im going to buy some and gut them

 

in areas where they still do emission tests, the use a mirror to look under your car to check for cats.. because of that many ppl gut the cat then weld a straight pipe inside of it.


my 1st car was a 92 sentra with a gutted cat and it still passed the sniffer test.

 

i dont think they even use sniffers on obd2 cars, i passed 3 times with my catless rsx

 

http://my350z.com/forum/intake-exhau...tock-cats.html

These are with 350z but they do talk about some dynos with gutted cats. Hope it helps

 

yeah i saw that, guy said 246 with popcharger and gutted cats and the other guy did 244 with just a catback

problem is there is no graph so we can't tell if there is a loss of lowend

 

Personally I think there would be loss in lowend. When I added my HFCs, HKS exhaust, intake, and 1/2" plenum spacer, I could tell it hurt lowend. But topend was completely different. It wasn't until I tuned the car that I gain some low to mid range back.

 

yeah probably

 

There was a article from Import Tuner in the April 2009 Issue # 121 that did a dyno comparision. It was under the title, "Fact or Fiction Debunking Tuning Myths"... The hollowed-out catalysts actually lost horsepower and toque over stock. in the third comparision, Testpiipes made 1.3 hp and 1.27tq over stock.

Check these two links out.

http://www.importtuner.com/features/...val/index.html
http://www.importtuner.com/tech/impp...ion/index.html

 

now that is the answer i was looking for! lol