Which flowmaster's best for Proformanceunlimited's 400HP FE?

[robroy]

Good evening,

I spoke with Steve today at Proformanceunlimited and asked him about exhaust. He recommended flowmaster 40 series mufflers.

I went to http://www.flowmastermufflers.com/ and looked at their different models, and naturally it's not exactly that simple.

I'm interested in a strong sound, but nothing that will set off car alarms in parking lots or give me a headache after an hour on the freeway. My truck came with rotten glasspacks installed that accomplished both of those things!

Does anybody have opinions or suggestions on how I can evaluate the choices?

Thanks very much!
-Robroy

[Wes]

I put 2 of these on a 66 Chevelle with 400ish hp sbc nice and quit inside throaty when ya jump on it. http://www.flowmastermufflers.com/50_delta.html
for duals 2.25" and single 3".

I have a series 70 3" on a suburban single, it sets off car alarms, but not bad in cab.

[BobbyFord]

FWIW, a guy on an engine forum did a dyno test using the same engine with different exhaust and found that Flowmasters actually hurt performance, considerably. The winner of the test were MagnaFlow and DynoMax.
I think the MagnaFlow's sound better than the SlowMaster's anyway...

[BobbyFord]

FWIW, a guy (engine builder) on an engine forum did a dyno test using the same engine with different exhaust combinations and found that Flowmasters actually hurt performance, considerably. The winner of the test were MagnaFlow and DynoMax.
I think the MagnaFlow's sound better than the SlowMaster's anyway...

...oops meant to change a few words and quoted by accident

[sideoilerfe]

I think I'm gonna get rid of my flowmaster. It's too noisy for me. I'm digging the Dynomax on my '68 better.

[averagef250]

The 40's are too loud for more than 10 minutes of driving.

I ran the 2.5" 50 series three chamber deltaflows for lots of miles behind a healthy 390 and they were great. They had a real nice truck rumble at idle, I could just hear a nice tone cruising down the freeway, but step on it and they sounded great.

I've also heard 2 chamber or larger flows aren't the best for all out HP, but they're still pretty good and some do sound pretty good.

[green70]

the 40's will set off alarms left and right,i swaped mine out for some 6"round magnaflows and im very happy with them,not as loud and feels like theres more power,its strange that there straight through mufflers yet there less noisy than the flowmasters

[robroy]

'Afternoon Dustin, Green70, Sideoilerfe, BobbyFord, and Wes,

Thanks for all the great replies. I'm glad I didn't order the 40's then!

It sounds like I should investigate either the Flowmaster 50 series, MagnaFlows, or a Dynomax.

Does anybody else have any comments?

Thanks very much folks,
-Robroy

[robroy]

I think I'm gonna get rid of my flowmaster. It's too noisy for me.

Sideoilerfe,

Which Flowmaster model are you running?

Thanks!
-Robroy

[Redcap]

Magnaflows for the win. I really hate the sound of Flowmaster 40s.

[robroy]

Aaron, thanks for your post!

Does anybody have a video clip of their truck that illustrates the sound of a particular exhaust type?

-Robroy

[sideoilerfe]

I think I'm gonna get rid of my flowmaster. It's too noisy for me.

Sideoilerfe,

Which Flowmaster model are you running?

Thanks!
-Robroy

On my '70 hi boy, i've got 2.5 from the manifolds into the Flowmaster "Y" and then the 3" "Big Block" Flowmaster. I believe it's the 50 series. It was designed for RV/trucks in mind. It's not too bad but I'm kind of liking the quieter mufflers now days. It has a rumble at about 2000 RPM and when you really work it like towing a heavy load up hill, it sounds cool but like I said earlier, I might just change it for something quieter.

[flatblack]

cherry bombs

[DuckRyder]

The best flowmasters are the ones that are still on the parts store shelf...

Go with DynoMax Ultra Flows.

Seriously, when I was young (very) and had a 1800 watt stereo I thought flowmasters were cool. Yes I set off car alarms. I had a set of "delta" flowmasters on a Mustang SSP and they still droned something awful and you could hear them miles away.

We had some movie files with sound clips, you should listen to some of those if you can't find actual vehicles to listen to...

[robroy]

Good morning Robert, Sideoilerfe, and Flatblack,

It seems pretty clear to me now that Flowmasters tend to be louder than others, and since "loud" isn't something I'm looking for, I'll look at the DynoMax and Magnaflow mufflers.

I've been looking on Google videos and typing in the names of various mufflers. Of course a lot of the hits are these mufflers installed on Honda Civics. But there's the occasional vehicle that's comparable to our trucks.

Robert, when you mention that you had some movie files, does that mean they're stored somewhere on Fordification? I would certainly be curious to hear these.

Sideoilerfe, the two Flowmasters with "Big Block" in their names are some of their quietest mufflers! So if these still seem loud, and other mufflers don't, does this mean that Magnaflows and DynoMax mufflers are even quieter? Quieter than the quietest Flowmaster?

Thanks very much for all the great advice folks!
-Robroy