verbs

I'm trying to convince someone that flowmaster catbacks are the worst ones out there for Fbodies. Does anyone have dyno numbers or first hand experience to support how bad they suck? If you did have positive results please post them too. Thx!

Phlip00WS6

iTrader: (7)

Flowmaster 360rwhp magnaflow 381rwhp

NHRAMAN

iTrader: (1)

DYNO PROVEN ?? WHERE..?? THAT is 21 HP.!!

99ccz28

iTrader: (6)

i went from a flowmaster muffler to a magnaflow muffler, i have 2 3/4 pipe, and now i spin my nittos drs from a slow roll pretty bad, i didnt do that with the flowmaster. so i figure that it must have made a pretty big difference

Phlip00WS6

iTrader: (7)

Yes, dyno proven. The flow master is with 2.75" catback and magnaflow was 3". Thats the only difference. Oh yea.. it was an 80 series "crossflow" muffler.

Fire-formula 93

iTrader: (1)

I hate trying to convince people that flowmaster sucks. Usually the arguement is similar.

"What! Flowmaster is the best! My buddy has flowmasters on his Mustang..." That is when I start walking away.

STRIPSTAR

iTrader: (4)

Shouldn't be so hard on Flowmaster. They have great products and ar ea cool company. Sure their ls1 catback sucks but for mustangs and muscle car etc they are great. There are quite a few people on here with true duals with 1 chamber flowmasters that are happy.

Zick

iTrader: (18)

Sorry not a dyno but how about a flow rating.


http://www.performancetrucks.net/for...7&postcount=36
That was pulled from this thread;
http://www.performancetrucks.net/for...ght=flowmaster

Wicked_Hugger99

iTrader: (1)

no dyno tests but when i bought my old 95 Z it had a flowmaster on it. I changed it to a 3in SLP LM with a moroso sprialflo muffler in place of the LM's resonator piece. and it picked up a 1/2 a second and 1.1mph in the quarter in nearly the same weather conditions as when it was run w/ the flowmaster a week earlier. Both setups ran a 2.5in ory. Thats my only experience w/ the flowmaster vs. whatever arguement.

RealQuick

iTrader: (14)

That tells me that the catback probably only gained you .1 sec. and 10rwhp based on the 1.1mph gain. The other .4 sec is driving (shifting, 60'). Normally, to pickup .5 seconds from power gains, you'll see ~5mph gain as well.

2000TransAmWS6

iTrader: (12)

336 rwhp with flowmaster and jethot removable cats
375 rwhp with tsp rumbler and cats removed.

before it just felt like the car was dying at high rpms, the car was litterly getting choaked.

FlashLCD33

iTrader: (8)

Not a valid comparison because you are comparing cats vs no cats, and cats obviously rob some power. However, that is a large jump Also, you're comparing true duals to a Y'd catback.

I like the sound of flowmaster super 40s on a stock !cat Z71, but they don't flow for ****

86 IROC

iTrader: (14)

I'll have to point my friend Mark to this thread. His old LT1 car picked up like 14-15 RWHP. That's through the Flowmasetr 3" cat back vs. open cut out on the dyno, same day.

I forget all of the details, but I know it had BBK shorties, !cats, hot cam kit, BBK 52mm TB, UD pullies, 3.73 gears.

I'll let him post up the exact details.

99ccz28

iTrader: (6)

maybe he means the 3in tsp rumbler catback not the true duals

BLK02WS6

iTrader: (2)

I have seen at least 3 cars that I tuned on our dyno that gained between 20 and 25 rwhp by ditching the flowmaster with either a cutout or a Magnaflow.

transAm-98

iTrader: (1)

mine isn't exaclty fair, but on my old tune i made 386/383 throug a flow master, and when i popped the cut-outs open i dynoed 415/411. the car also drives a lot smoother with the cut-outs open

HartAttack

iTrader: (8)

Here ya go

Chadder

iTrader: (2)

^

wicked_95z

iTrader: (8)

I ran a 1/2 second quicker after unbolting my flowmaster cat-back when I was still a bolt on car. Went from 13.7 to 13.2

pewter 01 SS

iTrader: (5)

not really true comparison but something that shows that it is really restricting.. i dynod 470/444 with flowmaster and with cut out open 517/487.. since then changed then i changed to magnaflow and dynoed with it on 500/480 with cut outs closed..