Whiteline Jim

Many of you would have seen while watching any telecast of the V8 Supercars in recent years, cockpit footage of drivers pulling on what looks to be a lever before cornering. It’s quite obvious that they are not down shifting gears, so what is it they are actually modifying while racing? It makes me very pleased to advise that from the drivers seat, they are dynamically adjusting the stiffness of the sway bar. Why? Because every split second counts on the track and by adjusting the sway bar rate to push or pull a car through selected corners can be the difference between setting a lap record, pole position or even a podium finish. It just shows the level that motorsports go to for that winning advantage and also shows how influential the right sway bar can be for performance.

For more on sway bars head to the Whiteline website @ www.whiteline.com.au

CASTER – WHAT IS IT?
Caster is the backward or forward tilt of the steering axis. Vehicle manufacturers are aware of the advantages of caster and as each new model is released the amount of caster specified increases.
Why, because the disadvantages of high levels of castor are being overcome. Rack and pinion steering means less play, lower Ackerman levels, smaller scrub radius (zero is now very common), better and lower profile radial tyres means less sidewall deflection and higher tolerance to greater slip angles. But the greatest obstacle, that of heavy steering effort, has all but disappeared with the universal acceptance of power steering.
High levels of positive caster equate to dynamic negative camber on turn when you need it most. Whiteline continues to put heavy emphasis on additional positive caster when designing new suspension packages.

Whiteline Jim Alignment Q&A
Q: Should I try adjusting caster or camber first to improve handling?
A: Caster, and here’s why:
1. Camber doesn’t improve turn-in, positive caster does.
2. Camber is not good for tyre wear.
3. Camber doesn’t improve directional stability.
4. Camber adversely effects braking and acceleration.

The latest installment of the world famous Grudge Match, sees a 2009 Subaru WRX take on its new equivalent, the 2008 Mitsubishi Ralliart Lancer. Off the factory floor, both platforms have had their critics, calling them uninspiring, but these cars are different and this shoot out sees both cars modified with Whiteline handling and MRT power packages. That’s right, these cars are definitely not standard, however the modifications that have been performed on these cars suit the budget of most enthusiasts, so they are very affordable, but most of all deliver bang for your buck performance.

Watch the videos:
Grudge Match I – EVO 9 Vs 2007 STi
http://www.youtube.com/watch?v=plJ6MzWcQGc
Grudge Match II – 2008 STi (Power) Vs 2008 STi (Handling)
http://www.youtube.com/watch?v=YqG2bNknOo0

Regards,

Whiteline Jim

jim@whiteline.com.au

www.whiteline.com.au

Introduction to Anti-Dive and Anti-Lift
“Anti” features in suspension systems are a characteristic that can be used to influence the stiffness of the front or rear suspension under traction forces (under braking or accelerating).
The individual terms are relatively straightforward and self-explanatory with the “anti” reducing or totally restricting the characteristic (lifting or diving). In the front suspension there may be levels of anti-dive during braking and anti-lift during accelerating (assuming traction to the front wheels is present), similarly in the rear there could be anti lift during braking and anti-squat during acceleration.
It should also be noted that these characteristic can also be reversed into a “pro” characteristic (as in pro-lift at the front under braking). Anti features can only be implemented under the influence of the braking or accelerating forces at the wheels, for example a rear wheel drive vehicle cannot have an anti-lift characteristic in the front (as there is no drive to the front wheels).
These characteristics do not change the steady state load transfer (during braking or accelerating) at the tire contact patch. The load transfer during steady state acceleration or braking is a function of the wheelbase, CG height, and the braking force.
100% of anti-dive or anti-lift would give no deflections of the suspension (from the static ride height) during braking and accelerating. It does this by passing the extra load during accelerations through the suspension components instead of the spring. Similarly 0% anti-dive would pass the entire load through the spring giving maximum deflections. Anti-dive and anti-lift are calculated by the position of the side view instant center; this imaginary point in space is generated by the geometry of the suspension system.

To read on, click here http://www.whiteline.com.au/articles/Effect%20of%20WL%20ALK_b.pdf

Regards,
Whiteline Jim
jim@whiteline.com.au
www.whiteline.com.au

The fitting of larger swaybars (rear and in general) has two main effects, vehicle balance in terms of understeer and oversteer, and increased roll resistance. Both of these can provide increased overall grip levels that can be achieved by the vehicle.
As most factory vehicles are biased towards understeer, fitting of the larger rear swaybar will help in providing a more neutral characteristic in the handling at the limit. This is due to the increase in roll stiffness at the rear, which loads the rear wheels more unevenly and provides slightly less grip at the rear than previous.
At first this may sound sacrificial, however, as the rear end is resisting more of the roll, the front end resists less in proportion, leaving the front wheels more evenly loaded, therefore more available front end grip. In the end an increase in overall grip can be achieved by balancing the vehicle. A WRX or other front torque biased all wheel drive vehicle will benefit even more due to combined front end steering/traction demand.
Another effect of introducing larger rear bars is that the roll stiffness is increased, and chassis roll is reduced, this also reduces the effects of “roll camber”. Roll camber is the variation in the wheel/tyre camber setting due to chassis roll, and during cornering usually results in the outside wheels gaining positive camber.
By increasing the roll stiffness and reducing roll camber effect, the wheel/tyre stays closer to its wheel alignment setting or optimal setting. This can increase the overall cornering grip available, as the wheel/tyre does not lose as much negative camber at the limit.
The balance (and grip increase) of the car could also be achieved by reducing the front swaybar stiffness, however its roll stiffness would be reduced and roll camber would suffer. This would lead to large amounts of positive camber being gained on the outside wheels/tyres when cornering. This would result in a wheel/tyre that would not be at its optimal camber setting at the limit of handling.
This could be remedied with large amounts of static camber to counter act the positive camber gain, however the resulting tyre where, and straight-line handling effects would suffer.
To maximise wet weather grip, a softer overall setting would be required from dry settings. The reason for this is that a wet track cannot give the same friction values as a dry track and therefore overall grip will never be as high as in the dry (hence the amount of chassis roll will be lower as well). The suspension can therefore be soften slightly until the camber setting start to be compromised due to camber roll.
So to conclude a larger rear bar in the wet should leave the car balanced however it would be slightly disadvantaged due to the high stiffness.

The fitting of larger sway bars (rear and in general) has two main effects, vehicle balance in terms of understeer and oversteer, and increased roll resistance. Both of these can provide increased overall grip levels that can be achieved by the vehicle.

As most factory vehicles are biased towards understeer, fitting of the larger rear sway bar will help in providing a more neutral characteristic in the handling at the limit. This is due to the increase in roll stiffness at the rear, which loads the rear wheels more unevenly and provides slightly less grip at the rear than previous.

At first this may sound sacrificial, however, as the rear end is resisting more of the roll, the front end resists less in proportion, leaving the front wheels more evenly loaded, therefore more available front end grip. In the end an increase in overall grip can be achieved by balancing the vehicle. A WRX or other front torque biased all wheel drive vehicle will benefit even more due to combined front end steering/traction demand.

Another effect of introducing larger rear bars is that the roll stiffness is increased, and chassis roll is reduced, this also reduces the effects of “roll camber”. Roll camber is the variation in the wheel/tyre camber setting due to chassis roll, and during cornering usually results in the outside wheels gaining positive camber.

By increasing the roll stiffness and reducing roll camber effect, the wheel/tyre stays closer to its wheel alignment setting or optimal setting. This can increase the overall cornering grip available, as the wheel/tyre does not lose as much negative camber at the limit.

The balance (and grip increase) of the car could also be achieved by reducing the front sway bar stiffness, however its roll stiffness would be reduced and roll camber would suffer. This would lead to large amounts of positive camber being gained on the outside wheels/tyres when cornering. This would result in a wheel/tyre that would not be at its optimal camber setting at the limit of handling.

This could be remedied with large amounts of static camber to counter act the positive camber gain, however the resulting tyre where, and straight-line handling effects would suffer.

To maximise wet weather grip, a softer overall setting would be required from dry settings. The reason for this is that a wet track cannot give the same friction values as a dry track and therefore overall grip will never be as high as in the dry (hence the amount of chassis roll will be lower as well). The suspension can therefore be soften slightly until the camber setting start to be compromised due to camber roll.

So without reducing comfort, a Whiteline Sway bar will make your suspension system and tyres perform better, making the car more responsive while delivering more grip. Fitting a Whiteline Swaybar offers all round improvements in handling, tyre wear, comfort, safety and even load carrying. Its the best dollar for dollar handling improvement you can make! Whiteline Sway bars use the finest grade spring steel, are powder coated and supplied with high performance polyurethane mounting bushes in a DIY kit form, ready to simply bolt on.

Search for Whiteline sway bars http://www.whiteline.com.au/vehicle_swaybars.php

Flat Out,
Whiteline Jim
jim@whiteline.com.au

Whiteline Jim fast fact - “Bars on Cars… the biggest bang for your buck”

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