Thinking about either an hks super drager or skunk2 exhaust system for my 94, EG6, vti. Would like your opinion on the cat replacement. Is it better to get a cat by-pass or is it better to use a hi flow cat replacement? I have heard that any form of cat is a serious power restrictor and have always believed that a by- pass pipe is the best option. However i have also heard that you can loose alot of bottom end power by using this method. Can anyone shed some light on this matter?

 

you got it. with test pipe u loose toques and gain a little horespower. with a high flow cat, its the other way around

 

most modern cats dont cost much power at all. get a good high flow unit and go with that. it wont be a noticeable difference from the test pipe (except maybe with a turbo) and trust me, ive ridden in a couple of cars with test pipes and they stink like crap. thats worth a hundreth of a second on my 0-100kph time.

 

Thanks guys, ill go for the hi flow cat then, in the UK we have to get our cars MOT'ed every year, any cars manufactured after '91 must be fitted with a cat. So my mates with by-pass pipes have to remove them and refit the standard cat convertor just to get them through the test! Will having a hi-flow cat still get me through the emissions test?

 

it should. I mean, they don't call it a cat for nothing, as long as you get one from a reputable brand.

 

it depends on what kind of mods you already have on your car.

 

yeah, and im not sure about your testing criteria, but here in the states most high flow cats will pass.