Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

Sound Proofing Exhaust Drone

Calais57

Donating Member
Joined
Jan 29, 2009
Messages
196
Reaction score
3
Points
18
Location
Blue Mountains, NSW
Members Ride
VE Calais V 6.0
Hi guys
has anyone tried using "Dynamat Extreme" (see ebay) or any other specialist sound deadening materials on the boot floor and sides in a 6.0 VE to reduce exhaust drone?

The boot floor seems to be made of a very heavy plastic which I reckon must vibrate, cause a "drum" effect and contibute in a big way to the "drone".

What do you reckon?

Thanks
Calais57
 

monaro327

New Member
Joined
Jun 4, 2004
Messages
794
Reaction score
4
Points
0
Age
35
Members Ride
VZ Skaife Senator & VY SS UTE
i've thought about doing this but the stuff is so expensive.
 

gregg654

New Member
Joined
Feb 14, 2009
Messages
1
Reaction score
0
Points
0
Members Ride
vess
Ok here is an easy and effective way to reduce that drone noise.
Take out the spare wheel and jack place a thick blanket in boot well and make sure it covers the sides too. Replace jack and spare tyre.

Got this tip from an authorised Walkinshaw outlet.
 

Not_An_Abba_Fan

Exhaust Guru
Joined
Aug 18, 2006
Messages
14,298
Reaction score
825
Points
113
Location
Bunbury, WA
Members Ride
Strange Rover
You have removed the rear mufflers haven't you.....
 

Boonz

Donating Member
Joined
Jul 27, 2005
Messages
4,042
Reaction score
46
Points
0
Age
32
Location
berri, south australia
Members Ride
green 355 VG ute
nah the rear mufflers make a drone at about 1800-2000 rpm... while under light load, it is quite annoying

clark rubber have some sound deadening thats half the price of dynamat and does the same job, you just need to find an adhesive to affix it to the spare tyre well
 

Calais57

Donating Member
Joined
Jan 29, 2009
Messages
196
Reaction score
3
Points
18
Location
Blue Mountains, NSW
Members Ride
VE Calais V 6.0
Ha ha, funny Dannyboy!!

As a matter of fact I removed the 2 xforce rear mufflers and replaced them with bigger diameter Walkinshaw items (just bolted on). These are noticably quieter than xforce. The impact on drone was that it has moved away from the 1800-2000 revs range down to about 1700-1800revs. This is good because we do heaps of motorway driving at abot 1900 or so revs.

However, I still reckon my theory about the "wheely bin" plastic used for the boot floor and spare wheel well is correct.

This seems to be backed up by the post from Greg 654. Thanks mate - I appreciate it.

I will go ahead with the sound deadening and keep you all informed.

It surprises me that out of the 5 exhaust centres I have asked for advice, only one (the smallest one) seemed to have any really useful advice. For such a common problem this is a disappointment.

Wish me luck!!

Calais57
 

Not_An_Abba_Fan

Exhaust Guru
Joined
Aug 18, 2006
Messages
14,298
Reaction score
825
Points
113
Location
Bunbury, WA
Members Ride
Strange Rover
What you will do is limit the amount of drone you actually hear, you won't make it go away as it is the exhaust that is the problem. X-force is a cheap exhaust. IMO.
 

Calais57

Donating Member
Joined
Jan 29, 2009
Messages
196
Reaction score
3
Points
18
Location
Blue Mountains, NSW
Members Ride
VE Calais V 6.0
Ok "non Abba lover" - It may be true that that my attempts will just "limit the drone that can be heard", but drone is actually caused by a combination of the "sound" and low frequency waves that cause vibration in other parts of the car.

I also recognise that the xForce cat back system I have is not the most expensive one available. It was on the car when I got it and is a mild steel version, not even a new Stainless steel system.

Having said all that......... some comments:
- DannyBoyDS (aka Not an abba fan), time to come clean and stop keeping secrets - can you recommend a few brands that do not drone at all? I haven't heard of any after reading lots and lots posts on this and other forums. In fact the problem seems to be commmon across many makes of cars and lots of brands of exhaust systems.
- If the low freqency sound waves are causing resonance and vibration in the boot area, then multi layered accoustic material should 1. block the sound, 2. absorb the vibration in the plastic boot floor
- Fitting the 2 Walkinshaw rear mufflers has changed the drone so that it occurs at about 80kph (very low revs in 5th or 6th gear. Something like 1200 - 1500rpm). Amazing change!
- I tried Gregg654's trick of using thick blankets to line the boot and spare wheel well while we did a 900km drive over the weekend. Definitely helped quite noticeably, but drone still evident.
- planning to buy "dynamat" this week and fit over Easter. Think I will line the whole boot floor, the wheel well, the back of the backseat bulkhead and also under the back seat.

I'll let you know how it goes in a couple of weeks.

Cheers.
 

greenfoam

New Member
Joined
Jan 13, 2005
Messages
7,902
Reaction score
125
Points
0
Age
99
Members Ride
VP Executive R-spec
I think your ears adapt to be immune to hearing exhaust drone. My brothers VS 5 litre used to drone shocking bad when he got it, but I can't hear at all now and the car hasn't changed
 
Top