MG Sports Cars

Hi All,

I'm new to this group. I just acquired a 76 Midget and am in the
process of striping it down. I have a question for those who have
done extensive upgrades to their Midgets; but first some background.

I have fairly extensive experience in building stock cars and have the
capability to build chassis from scratch. We run late model stocks
and have built several street stocks (for others) where we put the
unibody on a tube chassis.

As for the Midget, I want to build a car that looks old but runs like
a modern day sports car. To this end, I'm considering things like
swapping out the engine / trans and rebuilding the suspension.

I'd like to hear opinions on;
- turbo charging vs engine swap;
- trans 5 speed upgrade;
- suspension upgrades such as replacing the front spindles to use
upper and lower A arms, rear 3 or 4 link, and coil overs;
- brake upgrades
- wheel and tire upgrades

Thanks in advance,

John Neblett

Hi John and Welcome!

First, let me say that if your building a chassis, you have the option of doing things that no one else, well most of us cannot do because you are going to only use the outer shell. There are Bugeyes with Hemis (the old Chrysler, not the modern ones) all below the sheetmetal because they were not confined to the inner sheetmetal that most of us decide to leave.

You may want to give a few more specifics on what you want with this car. I am giving some pretty big differences because you didnt really give me enough parameters.

So that said-

- turbo charging vs engine swap;
Engine swap... The 1500 (1493cc) Triumph Spitfire motor in that car is not the most practical to build up It can be done but if your talking about keeping up with say a Miata, which is not a fast car, then the 1.5L that is currently in thre in not good. the 4 speed behind it is dinky and is the wrong item to have with power in front of it anyways.

With unlimited room, a big block, but forget any type of left and right- straight only and then no acceleration because its all front end weight!

go with say a GM 60 degree V6 fr easy size and good amounts of power and upgrades. If I was going a V8 and external dimension did not matter but weight does, LSX series. Say the 5.3L version or the 5.7 but this is going to be a shoe horn and nothing anyone else can drive!

- trans 5 speed upgrade;
not possible with the stock unit although you could find a spitfire 4 speed w/overdrive and fit that.

Going with an LSX is going to leave you with the T56 so it will not blow up with that much power but that leaves you with very little room as the driver and passnger.

Going T5 5 speed leaves you with a number of engine choices and not much room lost internally. Two choices popular on this board are the Ford 302 and the GM 60 degree V6. The 302 really should have every alloy piece possible purchased for it and placed further back for weight distribution but this is from a guy that has only had a few in the shop to examine, not someone who installs them. The 60 degree is more compact and i have all kinds of good things to say about it but i will not on this post.

I like the idea of the LSX if money is no object but again, T56 as well as the overall engine arrangement may require quite a bit of machining to fit but a Midget with an LS1 and fat rear tires, not wouldnt that be fun! (in a straight line only unless $$ was sunk in to it but....)

- suspension upgrades such as replacing the front spindles to use
upper and lower A arms, rear 3 or 4 link, and coil overs;
There are Spridget specialists that have systems like this. Neat stuff but spendy. If your gong to start pulling this stuff off other cars, there are few that would fit and be sized right. Maybe the Miata?


- brake upgrades
With serious power neeeds serious braking. If you start to run back to the 1500, then the stock brakes are good. Want an upgrade from there? Go with the Spitfire rotors and MGB calipers if i remember correctly...? Adapter kits available at Spridget specialists such as sprigitech.

- wheel and tire upgrades
If your going with a more or less stock driveline or a Mazda RX7 driveline (I forgot to mention!!), then wheels and tire upgrades can be found in quite a number of places. If your going to do a serious suspension upgrade and abig driveline, then you need to consider the wheels after everything else is done or you know what you will need for al the sizings.

-BMC.

Before you get too far, I think you need to define "modern day sports car" more specifically, especially in terms of weight.

The Midget is so physically small... It has a shorter wheelbase and much narrower track than, for example, a Honda S2000 or anything Porsche makes. I'm thinking that you could realistically set a weight target of something in the ballpark of 1700 pounds... and doing so might make sense if you're trying to keep appearance basically stock. If you're vigilant about keeping the weight down, then all sorts of four-cylinder or rotary engines make sense.

This Smart "Roadster Coupe" doesn't look like a Midget, except in size... Note the 3-lug wheels! (It weighes 1743 pounds.)


I would certainly want a five speed.

There are lots of racecar parts already available for Midgets... racing suspensions, brakes, etc. - you might want to benchmark them before starting from scratch.

Modern day Bugeye:

Just for fun I'll play Devil's advocate here too. How about an aluminum big block Buick? We just got the weight figures for the new block and I was going to wait to get some comparison numbers before posting, but the bare block minus sleeves and main caps is 110 pounds. With a tube frame it might be possible to fit it in and the total weight of the engine could be within 20-30 lbs of a V6.

Jim

FYI

From the 12/04/08 Poughkeepsie Journal: Poughkeepsie, NY

MG 1977 Midget - Almost new: tires, gas tank & convertible
top. 46K mi. $2800. 845-489-2840

I have no financial interest nor any further info about this car.

John, in deference to our groups power hungry guy, Jim, I'd say no to any V8 just because of the width of the engine in the Midget chassis. You really have to get into the foot wells for a 90 degree V engine and also reloacate the steering shaft etc which is a real pain when so many other good options are available. There are so many questions which need to be answered before I'd even venture a suggestion, such as what type of performance you desire, great light quick responsive handling with loads of high rpm power or just good old torque for good street and highway running.
I kept my chassis pretty much stock with my conversion, but on the second time around I am considering some homebuilt front suspension and an IRS rear. If you build a seperate frame then these become even more desirable as it would almost be easier to scratch build a front than to adapt the Spridget design to a new chassis. Wheel and tire upgrades are going to be a real concern. The Spridget wheel wells are fairly small, but decent tire selection in both 13 and 14 inch sizes and to some extent 15's are starting to get limited. Of course wheel size will have a lot to do with the brake selection, if you keep the 13" wheels then you're pretty limited on the front to about a 9.5" disc. If you go up to a 15" rim then the disc size is much better but in some people's view you start to loose the "old car" look as the thin section 35 or 45 series tires look out of place.
Transmission choice is wide open, but take care with shifter placement as you can easily get a car that is uncomfortable to drive if the shifter is either too far forward or rearward. The Camaro style T5 fits pretty well and has a good shifter location if the bellhousing face is kept about even with the front edge of the heater support. You probably wouldn't want to move it much further rearward anyway as the tunnel narrows a lot in that area and you'd have to be cutting into the footwells for bellhousing clearance.
If the budget will allow probably the best overall engine I've seen so far in a Spridget is that Honda 2000 shown above, good low end torque for the street and then great high rpm power when you want. A GM V6 will give loads of torque and great power, but lack some of the rpm range as the twin cam fours. There my "ideal" choice would be a 3.4 based on the aluminum GM block with iron heads (about the same overall weight as the original engine) and the T5. That should be able to turn out around 200+ hoursepower at reasonable tuning levels which would make a Spridget a rocket with loads of torque from idle all the way up.