how bad really is flowmaster???

**Raoul-Duke** · 06-09-2008, 09:51 AM

ok heres the deal. i just picked up a 01 6speed z28 w 53k on the clock.

mods:
lid
pacesetter lt's w 3 inch ory no cat
flowmaster catback

i was goin to get rid of the flowmaster because i know how they are pretty restrictive. i wwwwas gonna go w a x-pipe true dual setup and dump before the axle..bbbut not gettin the dual setup would save me 600 bucks...

SOOO how much power would i really gain with a true dual setup like i just said vs. what i have right now??? is it worth it?....also im not planning on camming this car...

**Mr. Luos** · 06-09-2008, 10:19 AM

It isn't noticeable. 3-4RWHP is only noticeable on the dyno or at the track. And that is all the Flowmaster would restrict over another better flowing catback.

Although with a good true dual set-up, you would pick up 15 (or so) RWHP over any catback.

**Raoul-Duke** · 06-09-2008, 10:23 AM

Originally Posted by Mr. Luos

It isn't noticeable. 3-4RWHP is only noticeable on the dyno or at the track. And that is all the Flowmaster would restrict over another better flowing catback.

Although with a good true dual set-up, you would pick up 15 (or so) RWHP over any catback.

wow 15rwhp huh?? i also imagine it really benefit with a good pcm tune too huh?? maybe i will go w the true duals

**OnEbAdReDSS** · 06-09-2008, 11:10 AM

hey luos it also depends on what flowmaster it is (series)

**Mr. Luos** · 06-09-2008, 12:30 PM

Originally Posted by OnEbAdReDSS

hey luos it also depends on what flowmaster it is (series)

True.

Good or bad though, they are still all within a few HP of each other. At least on a mostly stock car.

**OnEbAdReDSS** · 06-09-2008, 12:51 PM

ya i know i got more with my 40 series than the flowmaster but then again if you go look up the design of the 40's series its like having a cut out but with a little sound deading

**N20LT4** · 06-09-2008, 01:00 PM

My car showed 12-14 rwhp difference from closed exhaust vs. open (cut-out) on the nitrous when I had the Flowmaster Force II 3" inlet/dual 3" outlet system (not sure what series that is, I think '80'). I made 3 runs a piece in both configurations. The car felt VERY restrictive and averaged roughly .2 slower times in the quarter-mile with the cut-out closed. I've then switched to a B&B Tri-Flo and haven't dyno'd it yet, but can tell you there is not nearly as much of a difference between open & closed as it was before. This is an LT1 car, so LS1 results would probably be different.

**Speed Psychosis** · 06-09-2008, 05:06 PM

since you have headers, there should be a great difference. i'd guess 15 at least with a good tune. also, texas speed has the cheapest dual exhaust im aware of. its about $450 and is dual 3" dumped. might want to look into that.

**nhraformula** · 06-09-2008, 08:10 PM

hmm, 12 h.p = 2 tenths.
above does not sound right

**0rion** · 06-09-2008, 08:15 PM

I've ran a flowmaster catback on mine for years and years and have an e-cutout on it too. I don't sweat a few HP here and there. I like the sound of it. If I want it less restrictive I just crack the cutout open a little bit.