Who’s tried 3 1/2” exhaust? On the street? With Flowmasters?
#2546722
09/06/18 03:19 PM
09/06/18 03:19 PM
|
Joined: Jul 2007
Posts: 1,686 Philadelphia
radar
OP
top fuel
|
OP
top fuel
Joined: Jul 2007
Posts: 1,686
Philadelphia
|
Howdy
I’m building a 400/512 for the street to go in a 54 dodge pickup on a heavily modified 2wd dakota chassis. I’m shooting for low buck and fun so part of the fun is scrounging and road tripping for cheap or cool parts.
A little back story and info:
I decided to go with headers not manifolds- got some crusty NOS no name long tubes 1 7/8” I think with short 3” collectors. Unported stealths, .507/.510 cam 240°/246° @ .050, rpm intake, 750 holley, mild built 727, 2500 stall, 3.21 gear.
I was always kind of against flowmasters because not only do they never score well in dyno tests I’ve seen but every jerk in a stock f-150 around me has that sound. I always get caught looking thinking a fast car is coming then it’s just a loud truck. I know sound is super subjective but for this build I actually want that deep hollow burbling idle and a loud wot too. I don’t care too much about giving up some power or off idle torque since the second half of my gas pedal will probably feel like driving on wet leaves anyway with 500+ tq in a 3000lb front heavy pickup.
So I got a complete 3.5” used but clean welded exhaust system with a 3” H pipe and flowmasters. I think they’re 40 series? The headers have short 3” collectors I am planning to neck up to 3.5 right after them then just put downspouts in front of the axle after the muffs.
I’m thinking it should be on the loud side but hopefully a little tamer than open headers or purple hornies or something. A little drone is ok it’s not a commuter car. I’m wondering if the huge system on the mild big motor will negate the famous power robbing reputation of the flowmasters? Luckily packaging isn’t a problem in a full frame pickup truck with running boards.
Does anybody have stories to tell about the flowmaster 3.5” mufflers? 3.5” exhaust in general? Am I going to kill a ton of torque? Wake the dead? I know I won’t have the over 600hp that would call for this exhaust and bigger headers too but it was $80 delivered and cartoonishly large I couldn’t help myself!
Radar
Last edited by radar; 09/06/18 03:21 PM. Reason: Typo
|
|
|
Re: Who’s tried 3 1/2” exhaust? On the street? With Flowmasters?
[Re: radar]
#2546735
09/06/18 03:32 PM
09/06/18 03:32 PM
|
Joined: Jan 2003
Posts: 13,416 Marion, South Carolina [><]
an8sec70cuda
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 13,416
Marion, South Carolina [><]
|
It will sound good in my opinion...I'm in the minority here that like Flowmasters. Contrary to what you see on the internet, you'll likely not lose any power w/ them considering how mild your build is. If they are 40 series, that's a 2 chamber. It'll definitely be noticeable, but not crazy loud. Here's my hemi w/ 4" single chamber Flowmasters. It's definitely a lot louder than yours will be. https://www.youtube.com/watch?v=FmOtBb4oaY8FWIW...my old combo of a 509/292 cam, ported iron heads, 440 that ran 11.40s at 117 mph in my cuda was with 3" exhaust and 40 series flowmasters. It ran the same with or w/o the exhaust on it.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
|
|
|
Re: Who’s tried 3 1/2” exhaust? On the street? With Flowmasters?
[Re: radar]
#2546762
09/06/18 04:22 PM
09/06/18 04:22 PM
|
Joined: Jan 2003
Posts: 17,926 S.E. Michigan
ZIPPY
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 17,926
S.E. Michigan
|
I used to have 3" H pipe exhaust, off of 3" collectors. At the time the car ran the same mph with or without the exhaust. Mufflers at the time were Hooker Aero Chamber.
Now I have 3.5" X pipe exhaust, coming off 3.5" collectors. Mufflers are Dynomax. Haven't bothered to test with/without.
Maybe both are overkill for my current power level...
I may never find out as I don't get too many chances to run with open headers.
Rich H.
Esse Quam Videri
|
|
|
Re: Who’s tried 3 1/2” exhaust? On the street? With Flowmasters?
[Re: angleiron2]
#2546804
09/06/18 05:40 PM
09/06/18 05:40 PM
|
Joined: Dec 2013
Posts: 4,715 Wichita
GY3
master
|
master
Joined: Dec 2013
Posts: 4,715
Wichita
|
I run 3" to the rear axle with Dynomax Ultraflows.
Pretty quiet inside the car. I do have carpet but no insulation.
I haven't tried with/without testing at the track, but I can't imagine it being very restrictive.
'63 Dodge 330 11.19 @ 121 mph Pump gas, n/a, through the mufflers on street tires with 3.54's. 3,600 lbs. 10.01 @ 133mph with a 250 shot of nitrous an a splash of race gas. 1.36 60 ft. 3,700 lbs.
|
|
|
Re: Who’s tried 3 1/2” exhaust? On the street? With Flowmasters?
[Re: radar]
#2546809
09/06/18 06:03 PM
09/06/18 06:03 PM
|
Joined: Oct 2007
Posts: 4,213 New York
polyspheric
master
|
master
Joined: Oct 2007
Posts: 4,213
New York
|
Are Flowmasters too loud? WHAT???
Boffin Emeritus
|
|
|
Re: Who’s tried 3 1/2” exhaust? On the street? With Flowmasters?
[Re: polyspheric]
#2546839
09/06/18 07:06 PM
09/06/18 07:06 PM
|
Joined: Jul 2007
Posts: 1,686 Philadelphia
radar
OP
top fuel
|
OP
top fuel
Joined: Jul 2007
Posts: 1,686
Philadelphia
|
Are Flowmasters too loud? WHAT??? Well flowmasters are not exactly loud- more like prone to have a nasty drone on cruise. It’s the 3.5” part that would make it loud. The whole system is like half again as big as regular 2.5” stuff
|
|
|
Re: Who’s tried 3 1/2” exhaust? On the street? With Flowmasters?
[Re: radar]
#2546911
09/06/18 09:16 PM
09/06/18 09:16 PM
|
Joined: Jan 2003
Posts: 12,327 Benton, IL.
DaveRS23
Special needs idiot
|
Special needs idiot
Joined: Jan 2003
Posts: 12,327
Benton, IL.
|
Go with a set of electric cut-outs and the rest of the questions are irrelevant. Make as much (or as little) noise as you want. And as much horsepower.
Master, again and still
|
|
|
Re: Who’s tried 3 1/2” exhaust? On the street? With Flowmasters?
[Re: radar]
#2547061
09/07/18 04:21 AM
09/07/18 04:21 AM
|
Joined: Jan 2003
Posts: 27,421 Balt. Md
383man
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 27,421
Balt. Md
|
On my sons Dart he runs the Flow Masters and when all capped up it slows the car almost 2 tenths. Just space the header collectors with a few washers and it picked up the almost 2 tenths. Its a little loud but who cares as its a hotrod. I run the Dyno Max Ultra Flows with the full 3" exh out to the rear of the car and I really like it. Its not to loud unless you step on it pretty good. I have never uncapped my car to see if my exh slows it down any. Ron
Last edited by 383man; 09/07/18 04:21 AM.
|
|
|
Re: Who’s tried 3 1/2” exhaust? On the street? With Flowmasters?
[Re: 383man]
#2547229
09/07/18 03:19 PM
09/07/18 03:19 PM
|
Joined: Aug 2003
Posts: 43,352 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,352
Bend,OR USA
|
My old pump gas Duster(518 C.I. 400 stroker motor) had a three inch system with 14x7x3.0 inch Magnaflow muffs with a side inlet and centered outlet mounted at the rear bumper. I ran it with the system on the car and ran it later with it removed, it ran 7.01 at 95.6 MPH in the 1/8 mile with it on the car and ran 6.99 at 95.8 MPH with it removed. I swapped the heads, intake and carb.later that year and it ran a best of 9.993 in the 1/4 mile at 134.+ MPH corked up with the air cleaner on using Oregon 91 octane pump swill
Last edited by Cab_Burge; 09/07/18 07:13 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Who’s tried 3 1/2” exhaust? On the street? With Flowmasters?
[Re: radar]
#2547264
09/07/18 04:54 PM
09/07/18 04:54 PM
|
Joined: Jan 2004
Posts: 4,590 Motor City
6PKRTSE
master
|
master
Joined: Jan 2004
Posts: 4,590
Motor City
|
I still have the 3-1/2" under my Charger with a X Pipe to 40 series 2 Chamber Flowmaster Mufflers reduced to 3" up over the axle out thru the stock tips. It has always been loud but not obnoxious & I always get a ton of compliments on how stock the car looks but idles & sounds so good. I did add some 3" cheery bombs on either side of the gas tank before the tips recently and it did quiet it down some & get rid of the drown it had around 45 MPH.
1963 Belvedere 440 Max Wedge Tribute 1970 Charger R/T S.E. 440 Six Pack 1970 Challenger R/T, 528 Hemi 1970 Charger 500 S.E. 440 4 BBL 1970 Plymouth Road Runner 383 1974 Chrysler New Yorker 440 1996 2500 RAM 488 V-10 4X4 2004 3500 Dually Cummins 4x4 2012 Challenger R/T Classic.
|
|
|
|
|