It is well worth getting rid of the cat, but I would buy a testpipe instead of hollowing out the cat.

Just make sure you get a spark plug defouler... so no CEL!

 

I already have installed a mechanical CEL fix for the HFC. Having a test pipe won't cause me to fail emmission, but it would cause me to fail state inspection.

Full Function, when I said "It's free" I ment hollowing out the cat, as opposed to buying a test pipe... but I see where you're coming from with the profit. Reason I don't buy a test pipe is because I have the bushur TBE and the HFC is flanged on one end and is slip fit on the other and uses a band clamp. I can't use just ANY test pipe.

I just figured if I can take my HFC out and gut it and throw it back on it 10 minutes and still easily pass state inspection, rather than buying a test pipe and having to switch it out for state inspection, the hollow HFC would be the way to go.

My one question was is there going to be any HUGE performance differance in a hollow HFC and test pipe?

 

There was a thread here before comparing the two. The test pipe made about 10 hp more.

 

Some guys gut the HFC and then weld a straight through piece of 3" pipe inside the hollowed out Cat carcass. The theory being that a gutted cat is more disruptive of exhaust gas flow due to its non constant internal diameter.

I personally don't think that there would be any measurable difference betwee a gutted HFC and a test pipe. I ran a gutted Random Techologies Cat on my Turbo Buick for years. Then I gutted the Evo's stock Cat as well. I say do it!

 

I searched before I made the thread and didn't find anything... But thanks. 10hpsacrifice isn't much for being free and passing inspection

 

I've read this on other forums when I searched google, but I wasn't sure if it applied to ALL cats, so I just figured I'd ask here...

Thanks for the info guys. MUCH appriciated

 

That may be "theory" but honestly... a gutted cat will flow better than a non-gutted cat. No doubt about that. May not flow as well as a test pipe due to it's inconsistant diameter, but I'm sure it'd flow MUCH better than an HFC, would you think?

 

A gutted HF cat may flow worse than it's original condition. The runners reduce the turbulence created from it

Stick a section in it as sparky said

 

I understand it will not flow as well as a test pipe... but worse than being in it's original condition??? I thought the honey comb was basically like a "filter" for exhaust fumes... not really there to prevent turbulance.

I'd think it would flow better, of course not as well as a test pipe, but atleast better.