Cat back crap attack.

**specialized.1** · 04-17-2007, 07:35 AM

I have a bad problem with my cat back. It is a Dynomax that was on the car when I bought it. It is only 2 and 3/4 inch. My QTP off road y is 3 inch. I know I can get it hooked up, but thought it would be 3 inch. A new cat back is expensive, but I might lose alot of flow if I use it as is. Shit I should have gone with duals for the price of the ORY and a new cat back. What should I do. What would you do? Sell this shit or? I don't mind losing 4.685 Hp, but I don't want to lose 14.689 Hp. Thanks.

**ss~zoso~ss** · 04-17-2007, 08:29 AM

no problem, you'll have to bring it to an exhaust shop and they can widen the end of the pipe, or cut a pice off of the cat back and weld it back up in with one end widened

**senicalj4579** · 04-18-2007, 08:40 AM

just get a pipe expander for 50.00 or rent one. all you gotta do is expand it to fit over your y pipe.

**9t8z28** · 04-19-2007, 07:50 AM

You will not lose much flow with the 2-3/4 mid-pipe

**JEB** · 04-23-2007, 07:23 PM

Suggestion!!! Do away with the cat-back and install true duals. You will like the sound. The added power isn't bad either.

**specialized.1** · 04-24-2007, 06:23 AM

Well I finally got the job done. Left the two and three quarter. I feel it is actually too loud. Might get used to it but I may go to a true dual later. I just know it must be down at least ten horse. Going from four inch Y to two and three quarter Yikes three would have even been bad enough. Should have got under the car after the salesman told me ya all catbacks are three inch. Oh and to top it off the borla is eleven hundred bucks.

**BlackLT1Z28** · 04-24-2007, 07:02 AM

Some of you guys are so paranoid with pipe size and flow. Depending on engine setup, a 4" pipe setup can be overkill.

**senicalj4579** · 04-24-2007, 07:42 AM

Originally Posted by BlackLT1Z28

Some of you guys are so paranoid with pipe size and flow. Depending on engine setup, a 4" pipe setup can be overkill.

3" starts loosing its efficiency after around 370 hp
3.5 starts loosing eff. around 500 hp
i'll have to dig up the math to find out what 4" is but i think i remember its like 650-700 or something. Yeah, 4" may be overkill on some cars but its better to have an efficient system