MGB & GT Forum

Finding my GT quite noisy and uncomfortable at highway speeds. Whilst it’s a delight at 50 mph with windows down it’s almost unbearable at higher speeds even in overdrive. Interested to hear from anyone who has gotten the NVH under control and what mods were done…...

Wind noise is a feature of the MGB GT. Many people have tried to reduce it, but the general shape of the body, plus all the sticky-out bits like the rain gutters, quarter windows, wipers, mirrors mean you are probably not going to reduce it much whatever you try. I think (only a guess) that the rain gutters are the worst culprit. There were no wind tunnels available to cheap car makers in the sixties and nobody considered it an important issue as long as the car looked good. I find the radio is a waste of time above 50 mph. On long trips I often wear ear plugs.

This is an extreme measure.
https://www.vord.net/cars/mgb_mods/noise/side_windows.html
Others have partially filled the gutters with a soft rubber tube.

The wind noise in our GT was coming from the vent window seals. I rebuilt those seals and it was significantly better.

With the OD your engine noise shouldn't be that annoying. My wife is really sensitive to noise and she wouldn't put up with the GT if it was doing 65 with a 4 speed. But with the OD she finds it not all that loud and I would agree. So I have to wonder if something else is going on in your case that is causing more noise to come from the engine bay and/or transmission. I can't imagine anyone's ears being more sensitive than hers. Shhhhhh...........she might hear what I'm typing here.......chuckle.

BH

Yes lol I wear ear plugs too at higher speeds lol - I will try a few of the ideas others have suggested and report back here .

. Even though I believe my car has an unleaded conversion head I added valve lubricant fuel additive that seemed to free the engine up a bit and make it a bit quieter - revs smoother to 3000 revs and is quieter at speed

I agree 100% Inevitable noise .

I've read this before about the GT being noisy. Interestingly (to me) I never read Dan Masters complaining which interests me as I'm using his car as a template. Not long ago we were having a discussion about eliminating the front 1/4 lights and sealing the rears. I'm not at that stage (yet).

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Mk1: CKD 11/66 first registered 8/5/67; owned since 3/77. 18GB +40 balanced. Peter Burgess BVFR head. Piper 285. 123. FidanzaFW. 4synch c/r box. Lots more as I did a nut and bolt rebuild; finished 2015. Tartan Red.

GT: December '78. VW Golf guards, flush fit front and rear valances. Torana XU1 vents, frenched indicators & Mk1 rear lights. 'Worked' Rover V8 with Monsoon ECU for EFI. GM4L60E, Lokar tiptronic & Quick4 controller. Vintage Air A/C. FC IFS. CCE 4 link rear. Salisbury with Quaife. Jaguar Storm.

I read somewhere that the Frontline LE50 has modifications to make their GT quieter.

You may want to investigate what was done.

As for my GT I installed Dynamat equivalent sound proofing throughout the interior.

I do get the aforementioned wind noise from the "A" pillar region, but very little road noise.

I lined the inside under the carpets with sticky back Butyl sound deadening mats. I also took the door cards off and stuck them to the door skins and fitted them around the trunk area. The doors now close with a nice "clunk". I also stuck them to the underside of the radio and arm rest consoles. I paid a lot of attention to the gear shift aperture which is open the the underside of the car.

Make sure the underside of the hood is lined and seal the holes in the fire wall with grommets.

I don't think you'll be able to do much about wind noise.

My main gripe is engine vibration. Mine gets bad at 3000 RPM. I can even feel it thru the steering wheel. The wooden Moto Lita wheel doesn't help.

Make sure that standard and not competition engine mounts are fitted. These can cause noise problems.

I suspected for a while that the engine might not have been balanced but last week I discovered that it has a solid crank pulley. These pulleys are supposed to have rubber Harmonic Balancers fitted in them. Mine doesn't so that's my next task.

AJ

Before I sound proofed my GT, I did a little research. You want three things: silence the sources, dampen the sheet metal, and insulate the interior. In that order.

For silencing sources, think get rid of that tourist trophy exhaust, but also replace the rubbers that mount the exhaust to the car. The rubber bushings of the suspension insulate road noise, check those too. Dynamat etc. dampens the panel drum, but does not insulate. That is what felt is for. In order to dampen panel drum you need to stick the dynamat (equivalent) to the panels themselves. When you tap the panel with your fingers you will note the difference. After 40-odd years, the felt has lost its insulation capacity, so you better replace it, but not without replacing the (missing?) dampening material first. Work through every panel on the car methodically.

Have fun :-)

Cheers, Andrys