Supercharging an MG TD – a follow up

It is about 9 years since I installed a supercharger on my 1953 TD and once fitted I wrote an article for TT Type 2 (August 2011} and the Octagon Bulletin (October and November 2011}. Nothing technical but just a record of my experiences and thoughts.

The supercharger and fittings were supplied by Steve Baker and we fitted it together. I say “we” but in reality, he did 80% of the work and I acted as apprentice mechanic and second pair of hands.

Subsequently I met Steve and his son Luke at the Stoneleigh MG event about 4 years ago when my car was on the MG Octagon Car Club stand. We had a good chat, during which time I promised to write a follow up article. This is it, albeit a bit later than intended! Rather than repeat what was written previously I thought that answers to the questions I get asked most frequently might be of more interest.

Why did you fit one?

As a kid I read all of Ian Flemings’ James Bond novels and the books mentioned the whine of the supercharger on Bond’s old Bentley. It sounded very exotic to me and that sparked the wish to one day own a car with one fitted.

What preparation was necessary?

The engine had not done too many miles since a rebuild so the compression was checked. As all cylinders were pretty much the same the only additional work was to replace the core plugs after thoroughly flushing the engine and radiator. I added a second fuel pump to mirror the TD MarkII layout, but in hindsight this was not necessary as a single pump would have coped. The gear box was rebuilt at the same time as this had been playing up.

Did you upgrade the brakes?

No, the twin leading shoe system on the car has been quite adequate for road use.

What maintenance does it require?

The unit fitted is an Eaton 45 and does not require any particular maintenance. As a precaution I do check the drive belt and all the pulleys and fittings regularly.

Why did you choose this supercharger?

I set out to get a period Shorrocks but couldn’t find one. This was available and as a complete kit, which is well engineered. Also, it looks very similar to a Shorrocks and coupled with the fact the maintenance regime is negligible, made the choice a simple one.

Has it impacted fuel consumption?

The simple answer is yes. Driving sensibly the car will return a little over 30 mpg. However, that doesn’t happen very often as it is far too much fun not to drive enthusiastically.

What is it like driving the car with a supercharger?

Not surprisingly, the acceleration is much improved and so is the torque, making the driving easier, perhaps requiring fewer gear changes. The normal engine running temperature has dropped from around 85 degrees to 78-80. It rarely gets above 85 even on a hot day or after a fast run. Starting in winter requires full choke but only for a very short while and in the summer very little, if any. Otherwise the TD gives the same pleasurable drive as always. The supercharger does whine, but quietly and only at higher revs.

Have you fitted a 5-speed gearbox or altered the differential to reduce the rev’s at higher speeds?

Not yet. I have been contemplating fitting a 5-speed gearbox for a while but haven’t found the time (nor the cash) to carry out the work. That job may have to wait until retirement.

Would you ever revert to the standard carburettor set up?

Not if can help it!

Colin Hooper August 2019

Colin’s TD pictured at a show soon after the supercharger was fitted.

Steve Baker’s website is:

Details of the Eaton supercharger are as follows:

Eaton M45 XPAG Supercharger Kit. £3,650.00 inclusive of VAT. The kit is supplied with fitting instructions and includes all necessary parts for installation, including a 1.5 rebuilt SU carburetor. The kit is set up for 6lbs boost suitable for fast road use.

Steve asks that you contact him in the first instance before ordering online.