MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MG Y Type - Sound Proofing

In an attempt to bring a touch of luxury into Y type motoring it would be nice to fit sound deadening materials to reduce engine and transmission noise. Where to fit it and what material to use is the question. I wondered if anyone has dealt with this problem
Bryan

Bryan

Most of the noise you are enjoying, comes from having floorboards rather than a nice snug monocoque cabin. There are also many avenues for noise ingress - the poor gearbox cover, the handbrake/tranny tunnel etc.

Of course the original Y had a bit of sounddeadening material - under the rear seat (for what it was worth), and under the dash. If your car is missing either of these then you will be getting more than normal noise. If these are fitted though and you want to eliminate hearing the tack-tack of the XPAG, the whine of the gearbox, and the droning hum of the rear diff, you could always ask a teenager with his baseball cap on backwards to fit a ghetto-blaster sound rig to the car with a 1000 watt amp and a sub-bass woofer (and I dont mean the canine variety) instead of the back seat!!

Other than that, I think you will just have to enjoy the sweet music from the Musical Trio (XPAG, 3 synchro box and a whinging rear axle) - when the music stops, you have either arrived where you were going ... or something has fallen off!! And if that is the case, you will know soon enough (as you wont have been going that fast) to be able to walk back and pick it up!

All of the above in jest though - have fun!

Paul :-)
Paul Barrow

I have also thought about this item. The case is as follows, there is noise and you can hear it. There are two ways to solve the problem, or you take away the noise or you make it not audible.
The first way won't go, there is to much noise from many different sources.
The second way is the easiest one, and I put this into practice. I use a pair of earplugs. When you choose one with the right damping, you can still hear the car but it is no longer annoying.
I was totaly surprised how nice the Y ran at once.
Bert Keuren

Taking off my MG owner's hat and getting out a very old and dusty acoustic engineer's hat; the first fact you need to know is that a 10% (by area) hole in a sound-deadening, sound-proofing, structure renders the whole thing useless.

I have not measured, but I am sure the gaps and holes in my Y are well over 10%.

Secondly, sound is stopped by mass and absorbed by light fluffy stuff so you need a mass-fluff-mass barrier for really effective sound insulation. Since the power to weight ratio is already on the wrong side of acceptable the suggestion of adding significant extra mass for the poor little engine to drag up hills is not an enticing prospect.

However, if you are determined, there are products that look like foam rubber but are backed with a very heavy backing called mass loaded vinyl. e.g. http://www.soundprooffoam.com/ultra-barrier.html
At 2 lb/sq ft the weight will add up but without the weight you are wasting money, foam wedges or other 'fluff' will not work by itself.

Contact me if you want to take this further.
Murray
MG

Thanks Murray

I have noticed that sound does seem to pass through quite small cracks or holes, thanks for pointing this out. The transmission tunnel and floor is covered by carpet underlay and the floor is mounted on felt strips which may help, but the main cocophony seems to come via the scuttle. I wondered if half inch expanded polystyrene panels may be effective glued to the interior of the scuttle.
Perhaps when the car was new there would have been much less noise from the drive train.
As for real pain in the ear my T type TF with the hood up at 4000 revs on the motorway takes the biscuit and is a real danger to ones hearing.
Bryan

Bryan

The polystyrene seems a poor idea. If you are looking for something to stoke up a good blaze, this is the stuff.
I know a fire is unlikely, but polystyrene will ensure it burns well.

Michael
Michael Nicholson

And polystyrene has negligble mass so will do nothing to stop sound energy. Only mass and separation work, it is the way the laws of physics work. Since separation, via physical decoupling, is going to be very hard to achieve, mass is the only option left open.

You could always hang some thick velvet drapes to absorb some of the sound energy that does enter the passenger compartment, thus reducing the reverberation. (Or even a few pairs of fluffy dice!)
MG

Velvet drapes? Fluffy dice, - Murray you will be suggesting a garfield stuck on the rear window next!

Paul
Paul Barrow

I have fluffy dice already and a BRY and ETH sticker across the wind screen on the TF but it hasn't made a scrap of difference, however the acceleration away from the traffic lights has improved.
Bryan

Having spent some time under the YT today, I noted that there is a layer of carpet underlay (felt) on the gearbox side of the gearbox cover.

It is certainly a close fit in places to the gearbox & propshaft, but it appears to be well glued to the cover. I might consider removing it from near the propshaft though - the consequences of it getting caught up at highway speeds is too risky for me.

This is in addition to the underfelt on the topside beneath the carpet.

I will climb under the car and take a photo for those interested.
Tony Slattery

Following my earlier story, I have tested various earbuds. The best result gave the caps of 3M no EN252-2. These are specially designed for mechanical metal sounds. You can buy them in the hobbyshop for around 7 GBP or 10 Euro. The caps can be divided into three steps in the ear for small, medium or large damping. But always you have any sound of the car heard. This method saves a lot of trouble trying to isolate the Y. It is a matter of thinking. When the weather is cold you put on a jacket, when the sun shines you put on sunglasses and if you do hear to much noise you use earbuds.
Bert Keuren

This thread was discussed between 21/05/2008 and 25/05/2008

MG MG Y Type index

This thread is from the archives. Join the live MG MG Y Type BBS now