JWGchevy

Is it a myth that high flow cats are worth it or are they just a waste of money. Wanted to get y'all's opinion.

Darkman

iTrader: (2)

It probably depends on the car, since different years start with different factory cats. On my 2005 CTS-V (LS6) I picked up 25 HP with 2 modifications one being high flow (Random Tech Cats) and the other being a lightweight flywheel. I believe at least 15HP can be attributed to the high flow cats. (Since I did not dyno with each of the two changes however, I cannot prove it.)

DANOZ28

iTrader: (1)

darkman you must have had some really restricted cats WOW! on our ls1's i would guess removing the cats would save you upto 8 rwhp & switching to high flow should get you halfway there. so maybe 4 rwhp. just my one cent opinion.

Darkman

iTrader: (2)

Another factor may be the difference in catback systems. The CTS-V has a high-flow cat back consisting of a resonator that is actually an X-pipe and low restriction mufflers connected with a true-dual 2.5 inch stainless steel system. So, on the CTS-V, once the factory cats are gone you are accessing a pretty good catback. I don't know how restrictive the LS1 cat backs are.

MikeWS6

They are too expensive and dont last long. Run no cats.

WS6ICK2k

+1 Doesn't flow better than running without them.

Justhereforinfo

iTrader: (2)

But it sounds like ****. Id rather sacrifice the 4whp personally than listen to that raspy crap

Rise of the Phoenix

iTrader: (27)

I don't think the cats are what takes away the raspy sound. I've got true duals without cats and it's not raspy at all.

joecar

Cats are for appeasing The Authorities... high flow cats can't get an EQ#... so The Authorities disapprove... so high flow cats do not help you, leave them off, you're no more illegal than with them on.

(not to mention your budget)

Rise of the Phoenix

iTrader: (27)

If you're needing them for inspection reasons, just hollow them out. Visually, they will be there, but nothing more than an open pipe.

LPE 403

iTrader: (6)

OP - not sure what you're you dealing with cube or power wise, but I gained a few gutting mine. Kooks duals....

Goosecaddy05

it depends on your mufflers... some will sound absolutely terrible when you remove the cats... i hate raspy tingy mufflers also... they make your car sound like a cheap barn door pos.... i recently removed the cats from my system and it just got a little louder... still has the same deep thunderous tone as before ... cant beat b&B exhaust for sound quality