Ok so I finally got around to asking about high flow cat removal and as usual I can't seem to get an honest quote around here.

The one LSX specific shop sent me a response back and I would like to know how accurate it is. They stated that if I removed the high flow cats that I would lose boost (which I agree with that statement the reading would be lower) but I would also lose power? I understand exhaust scavenging and backpressure and how superchargers work and I am under the impression that while yes my boost reading would be lower I would still be flowing the same amount of air into the engine and the flow out would be less restrictive... therefore having the same or more power with less of a boost reading.

I think of it like long tube headers with a supercharger. You add them on after you get boosted and while the boost reads lower the car still has higher HP.

The only reason I bring it up is because they want to put my car on the dyno and evaluate it before doing anything. I feel like they're trying to pull me into doing all these modifications and letting them do a new tune or whatever which is not what I'm looking for. The car already throws O2 codes after a while so I know the cats aren't performing up to standards. They're a reputable LS shop so I would like their help over many other shady places around here.

And please no BS over removing the cats because of personal feelings.

 

less pressure more volume. the more air and fuel you can move in and out of your engine the more hp youre going to make >>>.<<<

 

You will not lose power by removing your cats.

 

That's what I figured. I was actually under the impression that the less restriction I had with the supercharger the less stress would be on the engine. Sure my boost numbers wont be the highest but the power would still be there along with some more tone to my exhaust. Guess I'm going with the other decent shop... they can do custom work instead of the normal O/R pipe so I may have them make me some manual cutouts as well.

 

Caught something at the end of your post....about throwing a code after a while....

High flow cats will always throw a code....I believe it's the differential reading between the upstream and downstream 02....maybe a 420/430 code if I remember correctly. Nothing wrong with the cat.....just switch the Trouble code to "do not report" and all is good.

 

Yes you will lose maybe a pound of boost but it won't lose any power.

 

I have Kooks Headers on my car, it was explained to me from a Kooks rep that anytime you are making more than 12 lbs of boost you will blow the cats out, my cats became clog limiting air flow,robbing the car of hp.

 

Can I do this with a code reader or will it require a tuner? I don't have a handheld tuner myself and the last guy wanted 'a couple hundred bucks' to turn off the rear sensors.

Awesome... exactly what I figured would happen and what I wanted. Actually I want to put down your 630ish rwhp with this P-1SC and no cam swap... so I might toss on a 4" pulley or the 3.85" but hopefully the 4" will get me there.

I'm only hitting 7psi right now so I'm not too worried about blowing them out but I've heard from different people that had lower boost and still blew out the cats. I just never liked a car with cats in it. I want to hear a little of the exhaust noise and if its too loud I can always throw in a resonator like a M80 or Cherry Bomb. Tone it down a little but still not inhibit the flow.

 

The engine will lose boost, but it will be more efficient, so itll still make more power.

Boost is just a measure of restriction, put a banana in the tail pipe, and yea, she will make more boost, but it wont equate to more power.

Louis

 

 

AWESOME