how to get rid of the droning ? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Rhett · 06-02-2005, 06:14

XY wagon, 302W, C4, twin 2 inch system coming off cast factory manifolds.

I have a terrible droning sound from the exhaust below 75 kph. It gives me a real headache, and since I do almost 120 km a day, I really want to get it sorted out.

I've had a "H" cross-over pipe installed, but it made no difference. Each side has a single turbo style muffler towards the end of the tail shaft, just in front of the diff.

I'm considering placing a small hotdog each side at the end just in front of the chrome tips.

I've previously had a 302W XY sedan with a dual 2" system and manifolds and didn't have this problem and it sounded real sweet, but that was many years ago and I can't remember what type of system it was.

Any suggestions?

ebxr8240 · 06-02-2005, 06:18

Two resonators and maybe slightly smaller tailpipe, make sure they exit out back of car.Not underneath...

Rhett · 06-02-2005, 06:23

Where do the resonators go?

It's only a 2" system and the chrome tips are 3" and extend to the rear edge of the bumper.

ebxr8240 · 06-02-2005, 06:27

Yea its a pita but I guess where ever you can fit them ..Or better mufflers maybe cheaper in long run? Check that exhaust is not tight on any mount etc where noise can be transmitted through body...Strange but thick carpet in boot quietens things down somewhat...

Ghia5L · 06-02-2005, 19:09

I didn't know that droning could occur on a twin system? I thought a twin setup would cancel out droning due to the pulse phasing of the firing orders on the LH and RH banks...

Or as EBXR8240 suggests, could it be a vibration/contact issue rather than a sound (drone) issue, mistakenly observed as a drone?

-Dave-

reece1 · 06-03-2005, 05:32

Quote:

Originally Posted by Rhett

XY wagon, 302W, C4, twin 2 inch system coming off cast factory manifolds.

I have a terrible droning sound from the exhaust below 75 kph. It gives me a real headache, and since I do almost 120 km a day, I really want to get it sorted out.

I've had a "H" cross-over pipe installed, but it made no difference. Each side has a single turbo style muffler towards the end of the tail shaft, just in front of the diff.

I'm considering placing a small hotdog each side at the end just in front of the chrome tips.

I've previously had a 302W XY sedan with a dual 2" system and manifolds and didn't have this problem and it sounded real sweet, but that was many years ago and I can't remember what type of system it was.

Any suggestions?

i knew of three cars with this problem corrected by running another pipe parralel to original each side about 3 foot long with a dead end before the mufflers

the cam timing is not retarded is it.

macx · 06-09-2005, 16:06

I put on a 2-1/2" catback from Mustang on my
890 Lincoln Mark VII, just had to lengthen the pipes
a little in front of the mufflers, then had to reroute
around the bigger gas tank. I, too, have the drone,
mostly from 1500 to 2000 rpm.

It's caused by the pipes and the mufflers being the
same size, length, and the mufflers being in the same
position fore & aft on the pipes.

My stock exhaust had 2 diff length mufflers, and the
tail pipes were 1/8" diff size.

I put some of the new sound deadening material under
the back seat and under the rear carpet, and put
shields up over hte top of the mufflers. I made mine
out of sheet metal and fastened them on with long
U bolts to the pipes, but they are available commercially
check Summit, Jegs, etc.

It really helped, though I can still hear it a little.
I also changed rear gears to one deeper to get the
rpm up out of the drone zone for hiway driving.

Rhett · 06-10-2005, 04:36

You guys who have a 302W and twin system with stock cast iron manifolds and dont have any droning, can you please tell me which mufflers you are using and the configuration? Thanks

van59 · 06-12-2005, 02:13

Quote:

Originally Posted by Rhett

XY wagon, 302W, C4, twin 2 inch system coming off cast factory manifolds.

I have a terrible droning sound from the exhaust below 75 kph. It gives me a real headache, and since I do almost 120 km a day, I really want to get it sorted out.

I've had a "H" cross-over pipe installed, but it made no difference. Each side has a single turbo style muffler towards the end of the tail shaft, just in front of the diff.

I'm considering placing a small hotdog each side at the end just in front of the chrome tips.

I've previously had a 302W XY sedan with a dual 2" system and manifolds and didn't have this problem and it sounded real sweet, but that was many years ago and I can't remember what type of system it was.

Any suggestions?

An old trick I used was putting two 12 inch hot dogs one on each bank mounted between the end of the engine pipe and the start of the system, Plus I used berklee mufflers . This had a very deep note and fooled a alot of people who swore it was a 351c .

Young Angus · 06-12-2005, 17:15

Ive got the same drone on my 289W and ive got a single 2.5" system, but the exhaust guy said its not a very good system so i might upgrade soon. But someone said to me that the droning could be caused by loose mount points with the body, rather than them being too tight as previously mentioned. Whichever one of these (looser or tighter) is better, it'd be worth while checking them out.