Dear All,

This is my first time post in here , i got some questions for my 06 EvoIX(MR).

I want to know is the test pipe is better or High flow cat is better, because i already put the down pipe, o2 housing, test pie and cat back exhaust for my evo but i go to think if i put the HIGH FLOW CAT on my car, is it have any preformance on there ?


do you guy think WORKS high flow cat is better ? or is that same performace the factory Catalytic Converter or do i need change back my factory Catalytic Converter put on my car

how come i want to change back high flow cat on my car because i find out my rear bumper have very dirty after i change the text pipe


Tks

 

A high flow cat is more restrictive than the test pipe you have on there now. Leave it how it is and go get tuned.

 

Getting it tuned will lean it out and keep the soot off your back bumper. HFC's don't really do much anyway. Kind of like a mid point between a TP and stock cat. Half as loud as the stock cat, cleans the exhaust about 1/2 as much as a stock cat and robs about 1/2 as much power as a stock cat.
Get it tuned. Not only will it clean up your exhaust a little, You'll notice a HUGE difference in power with those bolt on's.

 

i went from an AMS highflow cat to a test pipe and the car definately gained power after going to the test pipe.

 

your car needs a tune and you wont find any dirt at the back of ur bumper

 

You can get a CF exhaust sheild if you need to, I don't like them though.

 

Is there any power to be gained using the stock cat and a CB and Downpipe since there is so much restriction in them middle of them?

Thanks.

 

a turbo back exhaust is the way to go,

downpipe, test pipe, cat back then get it flashed to make the most of the mods

 

living in CA, I would get a Perrin HFC for your set-up

 

Yes. You will gain power with an aftermarket DP and CB with the stock CAT in place. Swapping it with a test pipe will add the most HP while swapping with a HFC will be quieter, smell less, and produce a little less gain.

In Denver you are all good with a test pipe as emissions is only every two years and cops aren't ba!! busters about emissions usually (at least that's my experience with my catless wrx).

 

Yeah... I wasn't worried about the cops, more just being environmentally conciencious

 

test pipe

 

If you are concerned at all about inspections, you could purchase a straight section of 304SS and gut the inside of the high flow cat, and have the straight section run through the inside and then welded up. I know catco cats were 3" inner diameter, and a 3" outter diameter pipe fit inside of them absolutely perfectly. Tig weld the end together, and now you have a test pipe with the visual appeal of a HFC to an inspector.

 

Wasn't concerned about inspections, was concerned about the harmful effects running testpipe might have

 

Hi

I run a HFC, I have not noted any performance decrease over a test pipe. In the UK it passed our emissions test very easily, if you are concerned about your emissions, a good HFC is the way to go.

MB