Flowmaster deltaflow 50


Well-known member
I have a Flowmaster Deltaflow 40 series on my 22 coupe 200 with a 2" exhaust. The interior noise level is higher than I would like
Flowmaster advertises the Deltaflow 50 series as having reduced interior noise. Do any of you have any experience with the 50 series muffler?
Yep. On the (bad) advice of my muffler man, I have one on my Mustang with single 2 1/4" exhaust and it sucks. At 1500 rpm's it will drive you crazy with the droning. Sounds like someone blowing across the top of a big jug. I added a glass packed resonator tip; no change.

At idle it sounds good and at highe revs and at WOT it's got a nice sound, but just cruising is very bad. Never again. No more Flowmasters.

As soon as I get a chance, it comes off and some Dynomax turbos go back on with 2" V8 duals.
1500 is 30mph in third and 45 in 4th. Yep I drive it at those speeds a lot. :D

6000 rpm is (theoretically) 157mph in 5th! :shock:
All kidding aside...a lot of people complain about the droning sound in Flows, but to me this is the only muffler that really gives a hi-po sound to a 200 six. I've tried a lot of mufflers (friend owns a muffler shop) Borla, Dynomax,Thrush, glasspacks, turbos. The only I haven't tried yet are Manaflows and Edelbrocks because they're not available here. As Jack
pointed out the sound at idle and low revs is very deep and powerful. At full throttle is even better...doesn't sound like a six. Me, I like the Flowmaster sound at any RPM, but then again I think thats just me. ;)

Iam running dual turbo glasspacks from JC Whitney and everyone thinks I am running a V-8. It has a nice rumble to it and it is not too loud cruising, I have no problem talking or listening to the radio while cruising along. I do have the exhaust exiting out the back under the bumper and extending about 3" beyond the bumper.
I have a Flowmaster 50 series on my 4.0 Jeep.... At certain RPM ranges it does make the droning sound, but all other rpms it sounds great.... I think it sounds pretty damn good for a 6 cyl. The 50 series is quiter, though I'd suggest the 70 or maybe a Mangaflow.
I am running 2" duals , both run side by side down the passenger side, until they get to the rear axle and then I sent one over to the drivers side just before the axle, bends up over the axle and exit out the back.
On an NVH (Noise,Vibration and Harshness) article in a mag some years back, someone discussed fixes for awfull drones. Jack, have you considered clamping an extra exhast support plus clamp a 5 pound mass around the part of the exhast system that does the droning? I've seen it done with gearboxes on some cars which amplifiy secondary vibrations from engines. The extra mass may raise the harmonics to a point where you're never going to run into it.

The other thing is, are you sure its not the sump vibrating? They can make a yukky racket on a 4.1. A 250 is much noiser than any 200 engine I've ever driven.
GM has that as a bulletin for some half ton trucks.... There are complaints of vibrations at certain rpms.... They put a counter weight on the exhaust near the tailpipe...

But it's more of a noise than a vibration.... I think its how the muffler is designed... Instead of having glass matting it has all these V shaped channels, directing air every which way.... The noise the six produces doesn't completely agree with that design, making a sound like blowing over an open glass bottle out your tailpipe at certain RPMs. Personally, it doesn't bother me a whole lot.
HillbillyHellcat":31p1v6jf said:
But it's more of a noise than a vibration.

Noise is vibration. Everything you hear is something vibrating at a high enough frequency to fall within the fairly narrow range of human hearing.
Xecute, it's definitely the exhaust system. If I take a rubber freeze plug and block half the dual outlet tip, I can induce enough backpressure that the sound is nice, but the power is way off. I feel I shouldn't have to resort to crutches like additional resonators, dampers and such to force the muffler to do its job.

I had duals on the car when I had the old 250 in it. When I installed the x-flow my muffler man convinced me to leave the headers as is (6-2-1) and run a singleexhaust. Bad mistake. The car only sounds good when you romp on it, but daily driving is painful. There's a big difference between Sound and NOISE.

I was pulled up next to a redneck Camaro today with two Flows hanging from under the car. It sounded lousy too. IMO, Flows are more hype than substance.

$64 bucks at Karparts :)

If flowmaster is a 10 on sound, the Dynomax is a 4, Db wise. Not installed in mine yet, but some friends have em. I have mine still sittin in box waiting for engine swap to be finished this week, then custom pipe and that gettin put on.
Anyone tried MAC flowpaths? They sound really nice on my 2001.

I just always heard stay away from Flows on our inlines. That's why I got my generic turbos. That and they were cheap and should do the job nicely.
I got my headers in and plan on getting my exhaust work done next week. Couple of questions:

1) Flowmaster 40 series vs 50 series? Which one sounds better and which one performs better?

2) My local exhaust shops are pretty pricey. Where is the best place to buy the mufflers? Anything else I should order when I get the mufflers? I currently have a no-name single exhaust and plan on pulling it out. I'd like to bring the new parts to the exhaust shop and have them put it together.

3) 1.75", 2", 2.5". What is the difference? What would be best for my setup? (see website link below for future buildup.)

4) I have a Port divider but plan on installing it this summer when I rebuild my engine. Will the use of headers without the port divider cause any problems?