Flowmaster Exhaust Restrictive Or Not???

I HEARD THROUGH SOME SOURCES THAT THE FLOWMASTER MUFFLER SOUNDS PRETTY GOOD BUT IS VERY RESTRICTIVE, THE REASON IM ASKING IS THAT I HAVE A FULL 3" EXHAUST FROM THE TURBO BACK AND HAVE ONLY ONE CAMARO STILL DELTA FORCE FLOWMASTER, IT IS NOT LOUD AT ALL I EVEN HAVE A SET OF HEADERS AND STILL SOUNDS PRETTY QUIET, I HAVE HAD THIS SETUP FOR ABOUT THREE YEARS WITH NO PROBLEMS BUT THAT LITTLE COMMENT GOT ME THINKING, IS THERE ANY OTHER MUFFLER THAT WOULD SEEM TO WORK BETTER WITH THIS SETUP OR IS THIS OK :confused:
 
Marred4Life,

The general feeling is the Flowmaster is a restrictive muffler for the GN.

I’m not racer so I personally cannot bash the Flowmaster as I’ve had one on my GN for about three years now. I love the sound and without the CAT the GN has got a real nice deep tone. If your looking for the best flow then a straight through design muffler is the way you want to go.
 
I have the Flowmaster muffler on my 87
I still have the cat,and the car is very quiet.
I like it
 
If you look at the "Cutout" of the FLowmaster, which is on most of their ads, you will see that it contains a series of "V" shaped baffles, this causes a lot of turbulence in the muffler, and those baffles are what causes the resonnant sound that is the signature Flowmaster sound.
Now compare that to the "straight thru" type mufflers where you can look right thru them when looking thru the inlet.....get the picture, then you'll see why Flowmaster are considered restrictive. They are restrictive for the NA setups like on my Trans Am, so they are definitely a restriction for turbo applications, you want the least amount of backpressure as possible after the turbo for maximum spoolup.
You may also be surprised to find out that most hi-flow cats will outflow a Flowmaster muffler.
 
Here is how restrictive it is.....

I have my car tuned for 21 lbs of boost (with alky)

The car has stock exhaust from the cat-back with FlowMasters. Probably the worst setup for a turbo charged car but it was that way when I got it and I have been doing other upgrades.

One day, I figured that I would make a pass, with the cut out. I looked at the boost gauge and it was at 28 psi. Thank God for alky and no knock.

I instantly let off and put the cap back on the dump. Made another pass and it was back to 21 psi.

7 PSI restriction is a pretty big problem in my book. I can't wait to order my new Hooker exhaust w/ straight through mufflers.
 
I'm a big fan of the Dynomax Ultraflow series mufflers. I've used them on my last 2 Camaros and I will get a pair for my GN. They are straight through type mufflers, no baffles, no restrictions.:) Excellent flow, but not too loud....and pretty inexspensive.
 
Jolly460 said:
I'm a big fan of the Dynomax Ultraflow series mufflers. I've used them on my last 2 Camaros and I will get a pair for my GN. They are straight through type mufflers, no baffles, no restrictions.:) Excellent flow, but not too loud....and pretty inexspensive.

I have one 3" pipe, one Ultraflow, and a Pitbull where the cat used to be.
Works for me....

My truck will soon have one on it, they IMO, just flat out work.
 
had a flow crossflow on mine, went to the hooker system and picked up 4/10.....that is a lot on a relatively stock car
 
thanks for a the replies, i have no problem with my exhaust its just i wanted to clearify the comment that someone made to me, know if i were to switch my muffler witch one would be best, i want a straight through flow with a camaro setup (1 inlet, 2 side outlets) im trying to get the most flow possible :biggrin:
 
buzzman,is the Hooker exhaust system you are using a single muffler or dual mufflers? Do you have the part # for the system you're using?

btw,nice ET
I'm hoping to get at least mid to high 13's with mine on street tires.
 
I picked it up from summit for $300 and highly recommend it. sounds real good w/0 cat, comes with a test pipe and all hardware. the only problem is that the pipes do not exit exactly where the stock did, so i had to notch my rear flaps. my car is real low miles and show condition so that bothered me a little. i know not many others are still running their stock flaps but i do for paints sake. i highly recommend this system, very little drone on my car. my car is basically stock, with reds pump, 93 chip, dut neck, pump gas on street tires, i have gone 13.3 at 103 on a cool day. thats with a 2.05 60 ft time.
 
yes, that is the right part number, however mine came with the aerochamber muffs, those in the picture are black, mine were not. the aerochambers flow real well, i would call them and ask
 
I bought a car a while back an it came with 2 1/2 duals carried it to the track an could not get above 18 psi. Had a feeling that it may be the mufflers an so it was 2 chambers.Took them out for straight pipes an instantly got 22 lbs with nothing else touched.. My opinion is a NA engine needs backpressure to make power an a forced induction motor need the least amount possible hence straight thru desing mufflers. I now have a 4" Dynomax Race Magnum an lets just say you could dry your hair standing behind the car.. My current car had the Summit Hooker set-up but it had there top dog muffler Max Flow's.. car sounded well an there are cars in the low 10's with this set up. after my build Ijust wanted something different.
 
i love the sound of my Flowmasters, i have had mine on there for about 6 years.. They aren't to RESTRICTIVE for me.. i went my best time (10.40 et) WITHOUT my test pipe open, with 3 chamber flow's.. That was with only 23psi on my new motor set-up..
 
I dont know about restriction, but I hate when they really shine through with their nickname -Dronemasters-.
 
buzzman said:
I picked it up from summit for $300 and highly recommend it. sounds real good w/0 cat, comes with a test pipe and all hardware. the only problem is that the pipes do not exit exactly where the stock did, so i had to notch my rear flaps. my car is real low miles and show condition so that bothered me a little. i know not many others are still running their stock flaps but i do for paints sake. i highly recommend this system, very little drone on my car. my car is basically stock, with reds pump, 93 chip, dut neck, pump gas on street tires, i have gone 13.3 at 103 on a cool day. thats with a 2.05 60 ft time.

I had the same problems with the exhaust tips not coming out right - one side was close, the other off - I'll have to re-adjust the mufflers and pipes later, but like the sound, cost, and quality... :)
 
drone

The only muffs that don't drone at some point is really quiet turbo muffs.(can't hear it anyway) The straight thru style mufflers sound like a pissed bumble bee at full throttle. And every single shot I have heard is very loud and drone is bad too. High flow cat tones down the drone too. Need boost took the hi flow cat off his car and it got a lot louder,he has a atr 3" dp and atr 2-1/2" cat back with pit bull muffs.
 
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