Midget Modifications

Fewer cars offer a higher fun/money ratio than Spridgets, although I believe it’s largely an illusion due to the car’s size and inherent steering responsiveness. When the driver’s rear end is located mere inches above the pavement and one looks eyeball-to-eyeball with an adjacent semi’s lugnuts, it doesn’t take extraordinary performance to make one of these cars feel like a street-legal go-kart. I’m fond of explaining it this way: you don’t drive a Midget so much as you wear a Midget. Although few drivers would rate the cockpit as luxurious, the overall experience of driving a well-sorted Midget is hard to beat despite the spartan appointments. It’s really all about enjoying the above-mentioned fun quotient above all else.

Featured in Classic Motorsports

Midget Modifications (as featured in Classic Motorsports) 1 Many people also find ownership of these cars enjoyable because of the simple technology that nearly anyone can understand and work on themselves. Being so basic, these cars are easy to modify and some projects can result in dramatic improvements from the original performance specifications. Unfortunately, some well-intentioned “improvements” can lead to problematic results. Here are a few examples from an exceedingly long list of common mistakes that might help you avoid making a Spridget mechanical blunder:

– Don’t change the car from steel to wire wheels without changing the entire rear axle housing. The wire wheel axles are nearly an inch shorter and, although they will move the car if installed in a steel wheel axle housing, the amount of axle spline engaging the differential side gear will be next to nothing. We have encountered this problem several times when repairing cars in the shop.

– Don’t use axles from a 948 or 1098 engined car if you have any performance ambitions whatsoever. They are made from material that is quite inferior to that used for 1275 or 1500 powered cars. Guaranteed to let you down when you least need or expect it.

– Don’t spin the rear wheels of the car when driving the car from an unpaved area onto a hard road. The shock generated by the abrupt change of traction is almost guaranteed to snap the right rear axle shaft effortlessly. Again, severe disappointment may ensue.

– Don’t change the front brakes of a drum brake car to disc brakes without finishing the job. Make sure you change the rear brakes and the master cylinder to those from a disc brake car as well. The front to rear brake bias will be changed to be far less than ideal if only the front brakes are changed.

– Don’t plan to put a 1098cc engine onto a smooth-case transmission that was behind a 948. The 1098 clutch won’t fit inside the bellhousing without very extensive modifications.

– Don’t try to solve a clutch release problem by lengthening the slave cylinder pushrod. The release bearing fork will hit the back of the opening of the bellhousing and bend it easily due to the force generated by the hydraulic pressure within the system. Instead of making the problem worse, fix the original problem, which is usually a worn out release bearing or master cylinder pushrod.

– Don’t fill the radiator in a cross-flow car through the pressure cap on the surge tank. That will only partially fill the coolant system and hot running will quickly result.

– Don’t choose the wrong alloy wheel to upgrade. Wheels have two measurements – their diameter and the width of the rim. While it’s easy to choose a wheel with the correct diameter, it is much more difficult to select an alloy wheel with the correct rim width. A wheel with an incorrect rim width will change how the wheel sits within the wheel well. A wheel with too much positive offset will cause the tire to foul the rear wheel arch; too much negative offset will foul the leaf springs. Your choices are limited.

– Don’t buy a generic fuel pump just because it’s cheap. Most will produce far too much fuel pressure which will result in the carb float needles being overwhelmed and then initiate serious driveability problems. Attempting to resolve this with a pressure regulator frequently produces further problems of leaking or inaccurate settings. Just ante up for the real SU pump and be done with it.

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