Whiteline Handling Pack

The scanned article

Typed Version, reproduced from Hot 4's Magazine No. 39, April '98 by Mark Tanner

The current Astina has been avery long-running model (four years now), but it's shape was so modern when released it reallly hasn't dated a bit. The original Astina in SP trim was a potent pocket rocket that established a small but loyal following among enthusiasts. The new series has continued that tradition offering very good performance value, adding the option of a V6 engine for even better performance.

The basic set-up of the Astina's suspension is very good, but suffers from prodigious understeer when pushed hard, due to the 'Wally factor'. What's the hell is that you ask? Wally factor is a nickname for the way manufacturers set cars up to take really bad drivers into account. Basically the brief for a front-wheel-drive car is that it must nevver oversteer. Even if the Wally driver lifts off the throttle suddenly in the middle of a corner in the rain, the car must must continue to understeer.

This is due simply because bad drivers have no idea what to do when a car oversteers. Undsersteer is considered the safest thing because if you drive into a corner too hard and start understeering, the car will tend to wash off speed until until it can make it around the corner.

Whitline's alterations are really aimed at restoring the car to it's true potential with the Wally factor removed. This means instead of understeering like crazy, it turns in welland feel balanced. Even with their mods you would have to be a complete Wally to get into trouble with the car because on a dry track I couldn't find a way to get the tail out.

Another concern with the Astina is that they look excessively high with large guard clearences and highly curved sill areas making them apear even higher than they really are. So how do you get one to handle really well but with a low enough stance to look good?

1a. Front Wheel Alignment

As with all front wheel drive cars, the first step to getting an astina to handle lies in increasing the front contact patch of the tyres when cornering, a larger rear swaybar helps but is not the complete answer.

Whiteline camber adjusters (TEC2380) allow 2.5 degrees. On the car we tested, the caster was at the factory specification of 2.5 degrees positive and the camber was set at 1.5 degrees negative, this resulted in a car that rapidly turned into corners in response to steering input. Even more caster would be desirable, especially as the Astina has power-steering anyway, but the design of the control arm makes it very hard to modify caster. If demand proves high enough Whiteline will produce a kit for this however.

1b. Rear Wheel Alignment

This is the real sleeper in tracks for getting your Astina to handle. On the test car the rear camber was set at 1.0 degree negative utilising the Whiteline TEC2380 camber adjuster. The toe out was set at 2.5mm oin each side, which is achievable with the standard Mazda adjustment system. The camber is neccesary to compensate for the roll, and the toe out is used to unsettle the back of the car on initial turn in to improve response. After initial turn in, the Astina then holds it's line superbly through the corner. Without sufficient camber on the rear wheels, a heavy rear stabiliser bar would result in excessive throttle-off oversteer, making the car difficult to drive on the limit (especially for Wally).

2. Rear Stabiliser Bar

As is the case with most front wheel drive cars, Astinas require a substantial upgrade to the rear stabiliser bar. Whiteline increase the rate of the rear bar by 70% with a diameter of 20mm. This results in greatly improved turn in as the weight transfer off the front wheels is dramatically reduced and therefore the front traction is improved. As the 'g' forces increase, the rearbar helps to keep the car upright and both front wheels are working to steer rather than just one. The rear bar controls the body roll and therefore the outside front wheel has a greater contact patch and hence more traction.

3. Front Stabiliser Bar

On the Astina, the standard front stabiliser bar is more than adequate in size. Whiteline simply fit their polyurethane bushes to the standard bar to ensure taht it operates at the same rate as the rear which is also fitted with polyurethane bushes.

4. Shock Absorbers

One of the most important factors in superior suspension setup is correctly matching the rate of dampening of the shock absorbers to the rate of the spring. You can buy good shock absorbers almost anywhere, but will they be able to control the spring and stabiliser bar, particular sports rated springs and stabiliser bars with in excess of 70% increases in their rates? Whiteline offer a tailor matched set of revalved shock absorbers to suit their spring and bar rates. These are made to Whitelines specifications by a variety of reputable manufacturers to guarantee an optimum result.

5. Springs

The Whiteline Select springs endow the Astina with a ride height of 345mm at the front and 345mm at thje rear with both measurements taken from the centre of the wheel to the guard. That is a substantial 55mm lower than the standard which is neccesary for looks only, a 40mm reduction in ride height would yeild almost identical handling quality. It is not possible to lowwer Astinas more, a fter many tests, Whiteline have found that further lowering does not allow sufficient travel for the bumps to be soaked up, causes shock absorber and drive shaft damage and adversly affects the handling.

The springs used in this article are developed and manufactured by Whioteline Automotive under their Select brand name and feature progressive rates where required, they are designed to work satifactorliy on their own as the only modification, but a complete package of all components working together is essential for the best results.

Part numbers can be found at the Whiteline web site www.whiteline.com.au