Removing The Guts Of A Standard Catalytic Convertor

[mspek]

This is the question that current faces me. I have a custom 3inch exhaust system end-to-end, & also a 'complianced' cat which sits in between. Do I get a 'hi-flow'cat? or do DIY using broom stick method to remove the guts of the cat!!

I am interested in hearing people that have done this? Did you experience or notice and problems after? I note 1 persons previous comments on backfiring..

People have told me that if I were to change my cat, to hi-flow, I would notice a big difference in power. Wouldnt removing the guts of the cat make this the ultimate 'hi-flow'.

I note that many people have bought either the Catco or MetalCat during previous group buys - so I am sure there would be interest out there?

[SKY031]

It's highly illegal and quite dangerous to remove the internals of a cat.

Cats are designed to flow.

If you gut the cat using the method you have suggested, it will interupt the flow, not increase it.

However, if you would like to find out first hand, and risk a massive fine, as well as risking inhaling the carcinogens contained inside the cat, then by all means go for it.

Unless it's a track car, get a proper high flow cat.

[Nismo_God]

but say you it is for a race car....what kind a improvements are we talking about if you have a straight pipe v's pipe with cat? just interested

[SKY031]

If it's for a race car, remove it altogether

[race_snooze]

there has been a few threads on this.. some even went as far as to dyno the difference from highflow cat to a straight through to busted out cat, the best was a pipe (straight through) then the highflow then the busted out cat.

[mspek]

there has been a few threads on this.. some even went as far as to dyno the difference from highflow cat to a straight through to busted out cat, the best was a pipe (straight through) then the highflow then the busted out cat.

I have looked everywhere for the link - could you please tell me where I can get this information you mention.

greatly appreciated.

[RB20_ZED]

i remember reading a very detailed thread on this - basically u dont want to do it coz its a crazy $10000 max fine or something like that...

and cops can tell by tapping on the cat if its hollow or not...

[MrStabby]

there has been a few threads on this.. some even went as far as to dyno the difference from highflow cat to a straight through to busted out cat, the best was a pipe (straight through) then the highflow then the busted out cat.

This makes sense because the compliance cat probably had a 2.5in inlet and outlet. The two step changes in cross section where it bolts up to the rest of the system will hurt flow, as turbulence is created up and downstream of the section change.

The original poster should bite the bullet and get the catco or metalcat. Better performance, no fines, and wont screw up the environment. Reaming the cat is the way of the bogon....you're better than that.

Rgs,

Kot

Edited November 14, 2006 by MrKotter

[Fugi]

I recently went to get a tune and found out my cat was restricting my power i then asked "could you just gut it" the mechanic then told me that they normaly put a straight pipe right through..(didnt reccomend it)

long story short. he gutted it for me and got an extra 5kw out of it.. but its just a temp thing im recivein my new 3" highflow tomoz.