Catback "good" (flowing) up to what horsepower?

**WS6Dream** · 06-03-2012, 10:46 AM

Doing TSP 1 7/8", TSP ORY, Magnaflow Catback, DMH e-cutout, lid, ls6 intake, sfc, p&p TB, 3.73 gears, moser axles VERY SOON.

I am just looking to the future, as to wanting to put parts on the car that I can use in the future when I am making more power. (H/C/I + nitrous or FI)

Also, with the above exhaust setup, CUTOUT CLOSED, should I expect a lot of rasp? CUTOUT OPEN, should I expect a lot of rasp?

Just making sure I have everything in order before I start putting everything on the car. Any input/advice would be great. I dont think I am missing anything.

I know that the car will be louder with the exhaust (what im going for...), but I dont want it to be TOO loud, how do you think the LT/ORY/magnaflow will do in that area?

Cutout = loud, really the only reason I am getting it is to have some fun hehe, but hoping not too much rasp from it.

And original question, what horsepower is a catback generally good "up to", before needing to be changed to true duals or something for better flow?

Thanks guys!

**raynor139** · 06-23-2012, 08:10 AM

Y-pipe setup is pretty much guaranteed rasp to some degree i have the setup as you and it is raspy. No where near as bad as some others ive heard especially loudmouth setups. Im having a cutout installed next month and thinking of having cats put in to help it with the rasp. As for noise the magna setup is very quiet at cruise speeds. Put your foot down and everyone will know your coming. Flow wise I believe its over 500hp a dual system starts to out flow a y-pipe.

**whitdog54** · 06-26-2012, 09:22 AM

Magnaflow sounds great even with ORY. Tame down low too. It'll rasp with cut out open but itll be so loud whoncares haha

**Firebirdjones** · 06-27-2012, 02:59 PM

Originally Posted by WS6Dream

And original question, what horsepower is a catback generally good "up to", before needing to be changed to true duals or something for better flow?

Thanks guys!

There are formulas for this but in my opinion, and what I've seen or done, the 3" single cat back systems are going to be a choker to some extent, even with stock to moderate power. Plenty of 400 rwhp cars with it though, and even some that are higher, but there is some power left on the table though. All the 500 rwhp cars I've seen or dealt with however always ran with either a larger 4" mufflex single catback system, or a true dual system.
Me personally, if I were shooting for big numbers and it's a weekend toy, I'd go for a larger I-pipe and avoid the 3" stuff, or stick a good dual system on it.
If it's a mild car and driven daily, the 3" single catbacks will probably treat you fine. You just have to decide what your ulitmate goal is and what you are willing to accept and not accept.

**Naaman** · 07-02-2012, 12:07 PM

I only have a cat-back, but it's a Magnaflow and I love it. It's very mellow at cruising speeds. And when you stomp on it, it sounds very smooth and healthy. Not stupid loud... which is nice because I don't like to attract a lot of attention when I'm at WOT.

**Firebirdjones** · 07-02-2012, 01:11 PM

Originally Posted by Naaman

I only have a cat-back, but it's a Magnaflow and I love it. It's very mellow at cruising speeds. And when you stomp on it, it sounds very smooth and healthy. Not stupid loud... which is nice because I don't like to attract a lot of attention when I'm at WOT.

You still have stock manifolds and cats?

I agree, I don't like to attract much attention nowadays either.

**Naaman** · 07-03-2012, 07:38 AM

Originally Posted by Firebirdjones

You still have stock manifolds and cats?

I agree, I don't like to attract much attention nowadays either.

That is correct, sir. I've been thinking about headers and y-pipe since I bought it. I just don't have the resources or the expertise to install them.

**SuperSSguy** · 07-03-2012, 03:14 PM

Nice COLOR !!! You have great taste!!

Then again im totally biased tee=hee..I have the same color on my 02 SS...they call it Sunset orange now but back in the day it was a Burnt Orange! I get lots of compliments on the color and ive only seen three around town so its unique. Kool car!!! Naaman

**SuperSSguy** · 07-03-2012, 03:22 PM

Originally Posted by Firebirdjones

You still have stock manifolds and cats?

I agree, I don't like to attract much attention nowadays either.

I also have Magna -flow cat-back..Yeah its a little tame @ idle But at WOT it screams ''here i come" !! Im running Kooks Lt`s & Kooks ORY/ hi flo cats. 3 '' exhaust . Kooks has a true dual set up now for my 02 SS but its expensive!!)I like the Magna too because it doesnt attract the local police or CHP (Calif.Highway Patrol) Because here if they suspect your car is modified they can send you to a smog referee and it can cost you a fine of up to $900.00 + the cost to re-do the exhaust to stock or C.A.R.B. legal!!! IT SUX.I want cut-outs someday too that way i can get noisy when i see a''stang'' and quiet when i see the po-po !