Flowmaster Series 70 muffler and DRONE!!! HELP!! - Ford Truck Enthusiasts Forums

Go Back  Ford Truck Enthusiasts Forums > Performance, Engines & Troubleshooting > Modular V10 (6.8l)
Reload this Page >

Flowmaster Series 70 muffler and DRONE!!! HELP!!

Notices
Modular V10 (6.8l)  
Sponsored by:
Sponsored by:

Flowmaster Series 70 muffler and DRONE!!! HELP!!

Reply

 
 
 
  #1  
Old 03-08-2012, 04:34 PM
Lizard 1
Lizard 1 is offline
New User
Thread Starter
Join Date: Dec 2011
Posts: 9
Lizard 1 is starting off with a positive reputation.
Flowmaster Series 70 muffler and DRONE!!! HELP!!

So, I had the shop remove the old system and replace the new piping (3" - stock) and run it into a Series 70 Flowmaster. Basically the same exact spec in terms of bends, etc but with the Flowmaster...

Sounds great at idle, but when you take off, you get a droney sound. My wife and son were following and he said it sounds like a fart can on a Civic. The biggest issue however, is at freeway speed...

At 55-60 MPH, the drone is so bad that I am seriously worried I made a mistake. It is really bad.

I called Flowmaster and asked them and they stated that V10s do have that sound, but the drone could be from the computer learning everything since I added the muffler. He said to give it a couple of hundred miles and then see how it does.

I have had 7.3s and if you put the muffler on the correct way, it has all the sound exit the tailpipe. If you put it on backwards, you will get a drone in the cabin.

Is it possible they put it on backwards?? I know they had a bright orange decal on the inlet end. Is there a way to check and see if it is correct by an embossed arrow or similar?

Do I need to get a resonator and put it before or after the muffler...
 
Reply With Quote
  #2  
Old 03-08-2012, 04:46 PM
dkf's Avatar
dkf
dkf is offline
Post Fiend
Join Date: Mar 2007
Location: Pa
Posts: 10,095
dkf is a splendid one to beholddkf is a splendid one to beholddkf is a splendid one to beholddkf is a splendid one to beholddkf is a splendid one to beholddkf is a splendid one to beholddkf is a splendid one to beholddkf is a splendid one to behold
I don't forsee the truck "learning" and getting rid of the drone.

Any aftermarket intake, y-pipe, headers and etc? Is the new pipe mandrel bent or typical exhaust shop crushed bends? What rpm is the drone at?

Anyway the Flowmaster 70BB2 is directional so it has to be installed properly. Below is a pic of the inlet and it should be stamped "inlet" on the case end.
 
Reply With Quote
  #3  
Old 03-08-2012, 05:55 PM
saggys
saggys is offline
Senior User
Join Date: Mar 2007
Posts: 169
saggys is starting off with a positive reputation.
Mine was droney to with stock manifolds and a SPD Y pipe. I installed Banks headers and Y pipe and it is MUCH better.
 
Reply With Quote
  #4  
Old 03-08-2012, 08:54 PM
Lizard 1
Lizard 1 is offline
New User
Thread Starter
Join Date: Dec 2011
Posts: 9
Lizard 1 is starting off with a positive reputation.
It might have the cat removed and the tubing is all mandrel bent.

Muffler is in about the same location as the OEM was in terms of distance back from the spot where the three bolts are. They welded everything and the only thing different from stock is they angle cut the tip. The piping is all 3" also...

I am not sure as to the RPMs as it is a van w/o a tach. Again, at 55-60 it is killer loud and from a dead stop, initial acceleration causes it to "braaaaap" and then fades to a nice growl.

I gotta go out and look to see if it is on backwards.
 
Reply With Quote
  #5  
Old 03-08-2012, 09:38 PM
Lizard 1
Lizard 1 is offline
New User
Thread Starter
Join Date: Dec 2011
Posts: 9
Lizard 1 is starting off with a positive reputation.
So, it is on correct. Inlet is facing towards the engine bay! Had to go out tonight and check or I wouldn't have been able to sleep!
 
Reply With Quote
  #6  
Old 03-08-2012, 09:54 PM
kas83
kas83 is offline
Senior User
Join Date: Oct 2008
Location: Plover, WI
Posts: 367
kas83 is starting off with a positive reputation.
I had an Original 40 on mine, was horrible with drone. I know the 70 is supposed to be better, but it's still a chambered muffler. Plus the body of a van is like a big drum.

I put a Dynomax VT on, no drone now.
 
Reply With Quote
  #7  
Old 03-08-2012, 10:37 PM
Lizard 1
Lizard 1 is offline
New User
Thread Starter
Join Date: Dec 2011
Posts: 9
Lizard 1 is starting off with a positive reputation.
Originally Posted by kas83 View Post
I had an Original 40 on mine, was horrible with drone. I know the 70 is supposed to be better, but it's still a chambered muffler. Plus the body of a van is like a big drum.

I put a Dynomax VT on, no drone now.
I know that I'd have to buy another muffler and then it is still a gamble in my mind. I was told the Series 70 was the right one and it drones like mad.

If I buy a VT, that's another $100. Plus labor to cut off and re-install.

Anyone doing a resonator? Just seems to be counter productive, though...
 
Reply With Quote
  #8  
Old 03-08-2012, 10:41 PM
kas83
kas83 is offline
Senior User
Join Date: Oct 2008
Location: Plover, WI
Posts: 367
kas83 is starting off with a positive reputation.
VT n 3 inch piping, with a 3.5 inch tip, thats it. My exhaust shop was nice enough to swap mufflers simply for the difference in cost between the 2, glad I paid the extra $120.
 
Reply With Quote
  #9  
Old 03-09-2012, 09:13 AM
Krewat's Avatar
Krewat
Krewat is offline
Super Moderator
Join Date: Jul 2002
Location: Long Island USA
Posts: 38,661
Krewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputationKrewat has a superb reputation
The problem is the lack of a cat - stuff a live cat in the pipe and it won't drone anymore

But seriously, without the cat, all I've ever heard from people with V10s is that the noise is unsavory.

A completely different setup, but on my '74 highboy that didn't need a cat, I had separate duals with thrush mufflers on it - drone. I added another muffler right after the first one on both sides, and the drone was gone.

I think some sort of resonator where the old cat was would help a lot.
 
Reply With Quote
  #10  
Old 03-12-2012, 10:42 AM
Fosters
Fosters is offline
Posting Guru
Join Date: Aug 2006
Location: Phoenix, AZ
Posts: 1,638
Fosters is gaining momentum as a positive member of FTE.
I've heard on multiple occasions people complain about the noise without a cat... Now, my mustang is loud enough to wake the dead, so loud is going to be relative. I have read about a few who have put a glasspack straight thru muffler in place of the cat; which got rid of the drone. They're not all that pricey and would be worth a shot IMO. They're definitely not gonna flow any worse than that huge cat.
 
Reply With Quote
  #11  
Old 03-12-2012, 05:07 PM
mwsF250
mwsF250 is offline
Postmaster
Join Date: Jun 2008
Location: Wayyy NoCal, USA
Posts: 2,564
mwsF250 has a great reputation on FTE.mwsF250 has a great reputation on FTE.mwsF250 has a great reputation on FTE.mwsF250 has a great reputation on FTE.mwsF250 has a great reputation on FTE.
Originally Posted by Lizard 1 View Post
It might have the cat removed

Then you might have identified the root cause!

Cats actually quiet the engine down quite a bit while eliminating the stink. And if large enough (like stocker), at almost 0 impact to tq, hp, or mpg.
 
Reply With Quote
  #12  
Old 03-12-2012, 08:03 PM
critterf1's Avatar
critterf1
critterf1 is offline
Posting Guru
Join Date: Feb 2010
Location: Newport, N.C.
Posts: 2,057
critterf1 has a good reputation on FTE.critterf1 has a good reputation on FTE.critterf1 has a good reputation on FTE.
Every Flow-Master I've ever dealt with had an annoying drone.
 
Reply With Quote
  #13  
Old 03-13-2012, 11:13 AM
cbzdel
cbzdel is offline
Elder User
Join Date: Oct 2011
Location: Tacoma, WA
Posts: 602
cbzdel is starting off with a positive reputation.
I cant even hear my 50 series SUV in the cab, but its really loud outside...
 
Reply With Quote
  #14  
Old 03-14-2012, 07:42 AM
Lizard 1
Lizard 1 is offline
New User
Thread Starter
Join Date: Dec 2011
Posts: 9
Lizard 1 is starting off with a positive reputation.
Update:

We put on a resonator. Helped a good bit, but there is still a drone... I am pretty pissed that I bought this muffler, had to add a resonator and still have that fart can sound. I should have bought the VT muffler instead it appears. I should have left everything stock and just been done with it.

Maybe it will get better as we go... The shop thought we could run a Cherry Bomb vs the resonator, but felt it would be louder...
 
Reply With Quote
  #15  
Old 03-14-2012, 07:43 AM
Lizard 1
Lizard 1 is offline
New User
Thread Starter
Join Date: Dec 2011
Posts: 9
Lizard 1 is starting off with a positive reputation.
Originally Posted by cbzdel View Post
I cant even hear my 50 series SUV in the cab, but its really loud outside...
I also think the older V10s sound different as i went through a bunch of YouTube vids and everything sounded good. I didn't connect the dots that my old V10 and their newer V10s could sound different...
 
Reply With Quote

Thread Tools
Search this Thread
Quick Reply: Flowmaster Series 70 muffler and DRONE!!! HELP!!


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.