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Arragonis 04-28-2010 09:09 AM

Just for Fun - Aeromod MGB GT

I have a 1972 MGB GT lurking unloved in my garage needing to be recomissioned. I'm kind of wondering about some ecomodding and aeromodding for fun as it will never be 'concours' again, until I can afford to reshell it.

The GT is the hardtop, coupe version. My unscientific examination (which consists of standing at the side of it, tea in hand and nodding like I know what I am doing) suggests the roofline is reasonable as is the trailing angle of the tailgate.

Profile image (this isn't mine, unfortunately)

Some spoilers (air dams) are shown here

Its pretty much a blank canvas at the moment though - no trim fitted and in pieces. I should consider a re-engine as well but its likely that the 87k miles B-series will stay with its twin SUs. It does have overdrive which is a bonus and it will get an electric coolling fan at some point.

Thoughts ?

gone-ot 04-28-2010 09:35 AM

...if "bricks" can fly, anything is possible, just to a lesser degree of perfection.

jime57 04-28-2010 01:57 PM

Had one of those myself - long, long ago.

The rear roof line looks fairly good. I think I would perhaps try a front spoiler with a soft bottom edge so you could get it nice and low. A grill block would help some, particularly in the winter. You might look at a good undertray both front and back. As I remember, the midsection of underbelly is fairly smooth. If you wanted to get radical, you might consider rear fender covers. If you have the disc wheels, vice wire, you might benefit from moon wheel covers. That might be hard on wires, though a j-bolts around some spokes would possibly work.

You could probably improve the engine efficiency a bit by installing a single carb for the pair of SU's currently on the car, though that is a guess. The "non-performance" versions of most British cars had that combo. Let us know if you try anything - and by all means, do some testing.

If you mereley meet he challenge of keeping the muffler from falling off, you will have accomplished a near unique result (tongue in cheek).

Arragonis 04-28-2010 02:54 PM


Thanks for the advice. I am serious about doing it but it is for fun rather than science. But it will be an interesting project I think.

Lowering is an option, however its already quite low (chrome bumper, not rubber) and it already risks grounding on speed humps. IMHO speed humps are badly named as they don't make me go any faster. :D

Made a rough plan - starting at the front. First step will be no bumpers and Sebring style valance - quite smooth and rounded. Oh, by chance I already have one. Also clear, flush covers for the headlights. Not sure about a grill block as coolling in a B is marginal in warm weather anyway - when it did last run I had to wait in the local supermarket for 30 mins whilst it coolled down to restart on a warm day. It may be worth part-blocking it or looking into something else here. I may look at a spoiler though if stability is an issue, the OC one is soft plastic. Otherwise I will leave it off.

Moving back the wipers are only needed for the MOT so they can come off after that. Mirrors can be 60s racing stylee - I only need a drivers (right hand) one anyway for the MOT. The rear I will leave bumperless and I may try smoothing the bits underneath the rear lights to the bumper area to smooth flow.

I can't see an easy way of removing the guttering (raid drip tray) around the roof - I can see that being the biggest drag.

Wheels are Rostyles (yeah :thumbup:) which are getting rare here so may be sold for funds. I have some older steelies too so I may go for flat covers and/or rear spats.

The underside is aero dirty until the B pillar where the floor starts. After that it is smooth except for the cross members. The area fore of this is quite dirty but I may look at smoothing it between the front valance, the engine cross member and the floor, and boxing in the floor itself. The rear is reasonably smooth with the tank fitted.

Some lightening has been done by the cheapskate use of fibreglass wings (have you seen how much a new GT wing is these days :eek:) and no trim, carpet etc. inside.

Single carb conversion may be a runner though. The Austin 1800 had the same engine with a single carb so there will be a manifold / carb combo somewhere for it. The only possible fly in the ointment is that the 1800 was FWD (also designed by the chap in the pic on the left) - think big mini with gears in the sump - so it may not fit under the low bonnet (hood). The engine does not have a lot of power anyway and needs overhauling really. Apart from this the mechanics are OK-ish - the overdrive works (or worked) as did the clutch and the axle was quiet. Front suspension needs an overhaul (I have polybushes to fit) but the rear has new springs and bushes in. The steering is OK. The dampers (lever arm - urgh) need overhauling but I will try emptying, flushing, new oil, pumping a lot, flushing again etc. until the oil is cleaner.

Initial idea will be to get it back on the road in basic form (bumperless though) and do some coasting tests in standard form and start the mods later.

Of course a lot of this allows me some 'bodging room' on the bodywork as my skills are mostly lacking in getting it to good classic condition. But the rat-look with some mods sounds interesting.



COcyclist 04-28-2010 05:47 PM

These ideas look good. IMHO the transition to the back glass looks too severe and the angle of the back glass looks too steep for attached flow. I'm betting a Kammback like AndrewJ's or TomO's would lower drag at the back of the vehicle.

Silveredwings 04-28-2010 10:04 PM

Before tossing the dual SUs you may be able to just re-jet them for the same effect.

Silveredwings 04-28-2010 10:08 PM

You might also benefit from an engine block heater (as opposed to thinner oil in that engine).

eco86 04-29-2010 11:11 PM

I think a front undertray would be fairly easy to form if you bolted it to the front crossmember and maybe attached it to the front valence somehow. I think they still make a "Special Tuning" front valence for the MG that works to divert air from the area directly under the engine, which I think is the most aerodynamically dirty area. It might help to invest in a heavy duty oil cooler, which might help to reduce the temperatures in the engine bay, although in my experience, getting the radiator cleaned out helps drop the temperature pretty well (and radiator shops do it pretty cheap). Flat disk wheel covers would look awesome on the MG, and also help with the aerodynamics a bit.

jamesqf 04-30-2010 12:53 AM

Can I offer a really easy two-step ecomodding program?

1) Sell MGB-GT to collector.
2) Use money to buy original Honda Insight.

kingsway 03-07-2012 12:57 PM

I also have an MGB-GT mouldering away and going to waste.... It was built in South Africa, so has never had any major rust. I probably should just put it on Ebay, but the thought of making it a bit more modern and economic to run is tempting (heresy to a collector no-doubt, but it is only a rubber-bumper version)

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