When i say removing it , its getting out all the stuff in it and keeping the "frame".


im planning that:
colder plug(installed)
3.25 pulley(got it, need a belt)
PCM
180stat(got it)
1.9 rocker
Ported manifold(may be)
Remove or buy a new cat.

i want to hit low 14'* on street tires. and also want to know if the cat help reduce knock retard or not.

a last question about the cat: does it sound good? i want to have a bit louder sound than stock but i dont want to waste money on an exhaust system.(the stock is OK from what i hear here )

for any hint.

For the price of a high flow cat there is no reason to remove it.

Cheers,

if you drop to the 3.25 you better at least port the manifolds along with your other mods

ok, for the advice, but did a performance cat will give more hp or simply remove the inside of the stock one will give same result?

i look around here and cant find performance cat for bonneville or GTP.

it look more simple to remove the inside of my stock one.

i can have it done for 60$ can.

did you know a place foghorn in montreal where i can get one? if its the better choice.

Personally i would probably go with the carsound 94009 high flow cat found here...http://www.justmagnaflow.com/Catalyt...ters/94000.htm Justmagnaflow.com has the best prices around. This is a very good high flowing cat and many of us have had good luck with it and its reasonably priced. Good luck.

From the air flow testing of a stock 2.25" cat on my flowbench, gutting it will add approx. 50% flow over stock. A straight pipe of the same diameter and length will more than double the flow capacity. I have been unable to test a high flow cat to see the actual flow capacity. Inlet and outlet size of the cat should make little difference, it is the size and makeup of the matrix that will matter the most. Not advocating one way or the other, but from actual testing, the hollow cat. must have a lot of turbulence or the flow would be closer to a straight pipe.

With identical mods the car with the Cat will be .2 sec faster in the quarter. PDad and I proved that last year. He removed his Cat this year.
....and it sounds much better without it. :P

you mean with the high flow cat?

.2 is a big difference!
and how much from stock?

I mean with no Cat. That'* what I've been saying all along but no one believed me that the cat makes that big a difference. Most will deny it because of environmental and legal concerns.

See my signature for mods. Last year when we proved the difference I had everything except the rockers and Lsd....and it was with a 3.4 pulley. This year we both had the same mods and both pulled a 13.9 quarter.

cool! ill probably to it next weekend.

Aahhh... 13.9 ... may be one day