Update by Tim Suddard to the
Austin-Healey Sprite project car
Sep 14, 2021
We had decided early on that while we did not want to build a race car, we did want to build a nasty, little Super Sprite that was indecently quick and would handle like a go-kart.
To that end, we talked at length with both Speedwell’s Tom Colby and Jeff Porada at the Winner’s Circle. We also spoke to longtime Sprite builder William Perry II at Rivergate Restorations.
They all helped us develop a plan for the suspension. Starting at the front, we’d need new spindles. Every expert advised us that the stock ones wouldn’t hold up to autocross use, especially with the wider tires and wheels we were planning to use: 6-inch-wide VTO wheels wrapped with 185/60R13 Federal tires.
[What size wheels and tires for our Bugeye Sprite? | Austin-Healey Bugeye Sprite Project]
While the original Sprites had drum brakes all around, front disc brakes from a later Sprite were a no-brainer. We'll grab the needed hardware from our MG Midget parts car.
We are using Porterfield R4-S high-performance street brake pads. We have used them on several projects cars, and they provide a great compromise between civility and braking performance.
Moss Motors sells Goodridge braided steel brake hoses, so we snapped a set of those up as well.
All our experts suggested a front spring lowering kit. This simple kit includes four spacers that lower the spring perches about a quarter inch. That should then drop the front end about half an inch.
Negative camber is the hooligan’s friend, and offset upper upright bushings will provide about 1 degree of negative camber. That should be good for our needs. If we need more, the lever shock can be shimmed. We’ll see if we need to take that more drastic step.
In the interest of ride quality, we will start with our stock front springs. Apple Hydraulics rebuilt our front and rear shock absorbers with heavy-duty valving.
The Sprite didn’t come with a front anti-roll bar, but we’re going to run a ¾-inch piece.
Now the rear suspension.
The experts didn’t agree on the need for a Panhard bar, but we decided to pick up a kit from The Winner’s Circle.
We’re going to grab the tougher axles from our Midget parts car. The entire brake system as well will come from that car, so we’ll install new wheel cylinders from Moss Motors.
An early Sprite most likely came with a 4.22:1 final drive. Will Perry II lives in the mountains of Tennessee and likes this ratio, even with his five-speed conversion.
As we are here in the flatlands of Florida and have a modified and supercharged 1275cc engine as well as a Datsun 1200 five-speed conversion, we are going to go with the 3.90:1 final drive that we found in our 1973 Midget parts car. (Measuring the gears is quite simple: We counted 10 teeth on the pinion gear and 39 on the ring gear. That equates to a 3.90:1 final drive.)
A quick note here: Our experts tell us that you can put any Sprite differential into any housing, but some clearancing might be necessary.
We then sent our differential out to our buddy Steve Eckerich who built a limited-slip for it.
All our experts agreed that a Sprite doesn’t need a rear anti-roll bar. However, our experts didn’t agree on how to prep the quarter elliptic rear springs. Tom Colby suggests removing the second, fourth and sixth leaves, replacing them with spacers.
Jeff at The Winner’s Circle suggested leaving all the leaves alone; then use tapered shims, found at shops that service truck springs, to mount the springs at an upward angle in order to lower the car a bit.
A Sprite is a tiny car, and the weight of the driver and passenger will make a difference as they sit over the rear axle. We are going to test out the full springs fitted with tapered shims idea as our driver is, shall we say, less than petite.
We are going to use a dual master brake pedal assembly from The Winner’s Circle to add in a bit of safety as the original setup relied upon a single master cylinder.
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