Here are the 40 series on my car...

 

The mufflers these guys like are basically glasspacks, and saying that flowmaster rob power is just hard for me to believe

 

andy,
what mufflers do you run?

 

Got them on my car. I love the sound, at the expense of what, 5 hp? If your scrounging that much, why have mufflers at all? Why not just tuned headers and save weight? The honest beef about FM to me, is corrosion. I'm not gonna pop for a $300 pair of stainless mufflers anytime soon.

 

Ive read an article on about a 425 hp small block, and Flowmasters robbed very little horsepower, maybe 3-5 hp to the best. IMO, if you like the sound, use em.

 

Fm super 44s 3 inch dumped at the rear axle, but a strait through muffler that has a perferated, or slotted or whatever tube with packing for sound deadener is a glass pack, and I know I'm gonna get flamed for it but I don't care!

Don't let these guys build your car for you,its not their car ,its your car use the parts YOU want to use

 

No, and don't believe the anti-hype.

 

I dig the sound of flows...always have & always will! I just wanted to try a set of packed muffs so went with borla xr-1's this go-round & I really like em, ALOT...still might add a flange in the rear so I can run a set of flows from time to time with sn easy swap! As far as flows being power robbers...maybe so, but prolly nothing you'll feel on the street...especially when your tires are always spinning! For a track car, I'd prolly go with a straight through muff or no muff at all...but a street car...go with what u think sounds the best regardless what anyone tells ya!

 

Idk if they rob power but I do know that EVERYONE HAS THEM!!! Everytime I turn around I hear flows. You know they are flows because they just have "that sound" where I live you cant get away from them.

Yes they sound great but tons of ppl have them dare to be different lol.

Ill be getting the moroso spiral flows from my car rignt now Im open headers lol I cant afford mufflers just yet.

As I write this 10 cars drove by with flows. And I live on a quiet street with little travle lol.

flows are nice yes but again EVERYONE HAS THEM!!!!

 

i got a set of flowmaster 30 series, love these things. They have a very unique sound that always draws attention. Sets off all the import car alarms too

 

i have them on my junk.
had them for years, love the sound.
they have an aggressive tone that really growls when i hit the loud pedal...

 

I ran a single in/dual out FM 40, with a FM Y-pipe on my last truck, a '92 Chev 1500 w/ headers, no cats and 2.25" tails. Got more compliments on how that truck sounded than anything else I've ever owned, and it was just a stone stock TBI 350 with some bolt on mods. The FM sounded great. Like everyone above has said, if you like the sound, get 'em!

 

i would like to hear some technical info on this ive searched many times... has anyone done any flow testing comparing them to other mufflers of course?
i mean i dont like mufflers like flowmaster and other of those style mufflers because i dont think there is any way that 3 plates and all of the other obstructions >>> like this can do anything but kill exhaust flow. jmo

 

Jim - A lot of people love our mufflers. The 90% you're associating with disliking Flowmasters are just the small percentage, but they are more vocal about their opinions.


If a Flowmaster muffler robbed power, then you are trying to put the wrong muffler for the application...especially in racing applications. We make nearly a dozen different street mufflers and just as many race mufflers for racing applications.







Ben - The muffler you've posted is a cutaway image of our 3-chamber muffler with a sound reduction chamber which cancels out higher tones, leaving only the deeper tones. Our 2-chamber mufflers don't have this chamber, hence the 2-chamber being louder than the 3-chamber Flowmasters. The 90-degree baffles actually work with the exhaust pulses coming from your exhaust valves opening and closing. The pulses passing the baffles actually create a low-pressure wave on the backside of each baffle that actually pulls gases through the muffler. This increases velocity of the gasses for better flow, which equates to power. There's a lot of science behind our mufflers.

 

had the Flowmaster crossflow kit on my Nova with an X pipe in front of it.. that car sounded wicked.
one of my friends had a Flowmaster cat back kit on his 95 Z28- sounded badass.
had a set of 40 series Delta Flows on my pretty much stock 74 Monte and even that thing sounded mean..
do they give up some power compared to a straight thru design? probably.. but how often will 5hp matter on a street car?

 

but how often will 5hp matter on a street car?

When it's an Import only making 95hp........and they need all they can getl

 

Some fm rob hp some do not..
I liked the sound of my old FM40´s.

 

When we swapped in the 540", new headers exited in a different place, fab'd x-pipe didn't fit without major rework, so connected the 18" case RacePro's as true duals. Was obnoxious loud. Replaced the RacePro's with FM 70 Series (5 x 10 x 22" case). Can't tell you on performance as there are too many other details to iron out, so no way to tell how much power is being given up. Sound quality is excellent, both in and out of the car.

 

Super 40's with FM American Thunder system and manifolds,no headers........YET.

 

Surprised nobody mentioned the drone at certain rpm with the flow masters. Mine sounded great but the drone at cruising speed drove me nuts. I switched to Ultra flows and love them.

 

I have witnessed flowmaster dual chambered mufflers kill ET by as much as .1 in the 1/8th. That is more like 30 HP on paper, but more than likely more atttibuted to the loss of torque which is where 1/8th mile ET is made or lost. This was on 2 different cars and with weather factored in for corrections. The flowmasters were swapped out for Dynomax bullets. I know, I know you aren't going to run bullets on the street, but it still proves the flowmaster chambered design does kill power. There are other mufflers out there that sound better and perform better. I have even seen flow data that show flowmasters chambered mufflers are the worst flowing out there. Not something you are going to notice seat of the pants on a street car, so if you like the sound then go for it.

 

If you are going to drag race a car it might as well be tuned for open headers. No restriction there. Unless there is decibal limit at the track why bother with mufflers? Flowmasters would be an improvement over a stock muffler any day. I think the sound is what people buy "performance" mufflers for anyway. I don't believe Flowmasters were intended for a competition application. Did you change jetting to correspond with the muffler swap? I'm not trying to be a wise acre, just curious. I agree though that you can't argue physics and that a flow through will be less restrictive than a chambered given same pipe diameters etc., but I would think that engine combo would play a role in how it responds to certain mufflers as well. On a side note, I like the Flowmaster sound. My father has Magnaflows and I think it is too blatty sounding. I put and AP Excelerator flow through on my truck and it is a little too quiet for my liking.

 

I have FM Kit # 17119 (Super 40 Series Muffs) 2.5" Mandral bent pipes attached to Hooker Headers # 2455- 1HKR Ceramic coated,
did not need to go to a muffler shop to have them installed, and the price was reasonable . :yes:
I get compliments all the time on the systems sound . They are not too loud, until I step on it.
Also I donnot think they effect my perf, see below for how my car runs at the track in street dress . :hurray:
I know I can run better as soon as I start working on the front suspension, spinning the first 60' .

 

My buddy has a 63 Chevy with a 406 SBC with 2-1/2" pipes and Flowmaster 40's. I don't like the sound. I think they are too loud and have too much resonance. I have a 70 Chevelle with a 454 with 3" pipes and Flowmaster Delta 50's. I love the sound and do all my buddys.

 

Chad, not sure if you caught my thread on the first outing with the 540". Combo is set up to be very mild, not to ET well. Car went 11.65/117.7 w/ 1.73 60' times. Don't know what different muffs would do, wheelspin is a huge problem as it is, even with the very low stall converter (rated 2700-2900, cant get much above 2500 before tires are getting fried). If the FM 70 Series are giving up 50 hp, from a race standpoint it's a big deal. From a cruiser viewpoint, doesnt make one bit differnce. The original Flowmasters were supposed to be a lot more restrictive than the current Delta Flow design ( as I understand). Power loss? If someone wants to ante up a set of 22" Magnaflows and some dyno time, Id be glad to volunteer my 540 powered '69 for some back to back testing and put the debate to rest.

 

Power loss? If someone wants to ante up a set of 22" Magnaflows and some dyno time, Id be glad to volunteer my 540 powered '69 for some back to back testing and put the debate to rest.

Will save you the trouble:

The absolute BEST mufflers are the Magnflow. I have been doing ALL my dyno testing with them ever since the Engine Master first contest.
The other day, on a 985 HP BB Chevy, when I took the 4 inch magnaflow mufflers off, it only picked 5 HP- that is unbelieveable. I have twice seen the mufflers make MORE HP than the open headers. You cant beat it. THey are prrtty quiet too.

JOE SHERMAN RACING ENGINES

 

My 70 SS454 has a pair of Flowmasters that have been on the car since 1991-1992...goes 108 MPH in the 1/4 with 3.31 gear..always wondered if a straight thru design like the Pypes or Ultraflows are worth a little more MPH

 

Have two sets. One a full Amercan Thunder exhaust with 50's, and some Super 40's dumped on the hot rod.

The full system has the best sound of anything I have ever heard, love it. Inside and out.

The Super 40's sound much nicer than the turbos before them, and seemed to help performance.

Two votes for them. I would venture that testing gas flow through exhausts is subject to lots and lots of variation....

 

flowmasters have a wide range... i am sure they have something for all budgets and uses....i have some cheapos from the local muffler shop....6 yrs later they still good.... i would prefer glass packs but i did not know better at the time.... the welds are a bit corroded but no probs with the mufflers themselves and sounds good,,,