S14 rear subframe bush kit KCA349

[260DET]

The fitting instructions with the kit indicate that tilting the subframe will change certain drive characteristics. Tilting the subframe forward (front lower) will improve traction, tilting it back (rear lower) is for drift.

Could someone explain the reasoning behind this? I'm particularly interested in how tilting the subframe forward will improve traction and what negatives this may introduce in circuit racing. And I guess others would be interested in the drift thing :)

[Jim]

Hi Richard,

Our Nissan tech is back on Monday and will respond in more detail but its about relative "anti" and "pro" squat geometry and how it can be modified to promote or reduce weight transfer.

Be back shortly.

Cheers
Jim

Whiteline

[Whiteline]

Anti-Dive and Anti-Lift

Anti-dive and Anti-lift are tricks that can be applied to a car’s front or rear suspension geometry to control brake dive and acceleration lift.

Lift and dive can be mitigated by carefully locating suspension pivot points to take advantage of the “force reaction” on the chassis created by acceleration or deceleration. By changing the angle of the suspension links, the amount of anti-Lift/Anti squat is being manipulated. The Whiteline kit is designed to take advantage of the dynamic suspension change under lift and squat by allowing slight movement through it's bushes

Cars like the Nissan R32 Skyline GT-R, Z32 300ZX and S13 240SX have a great deal of anti-squat in their rear suspension geometry. This makes them transition. To on-throttle oversteer very rapidly because anti-squat, like anti-dive, significantly increases the wheel rate. so by fitting the spacers This in turn multiplies the effect.This is why the S13 works so well for drifting.

Most racecar suspensions have much less anti-dive and anti-lift than street car suspensions. On racecars, the stiff suspension is used to control body motion instead of redirecting braking or acceleration forces.our kits available are designed to alter anti-dive and anti-lift work to reduce these factors.

There are many in depth discussion papers available on the net which go into in depth disscusions on how the percentage rates of Anti-lift/anti-dive are achieved here are some we have listed

www.whiteline.com.au/articles/WL_Solid_Axle_Antisquat.pdf
www.whiteline.com.au/docs/instructs/203a_KCA349.pdf


Regards,Dave

[260DET]

Thanks for that Dave, I now understand how the Whiteline kits works. Just to clarify one point, when you say that with the Nissans you've listed anti squat can significantly increase 'wheel rate', does that refer to the effective spring rate at the wheel?

[Whiteline]

Hi Richard,

Wheel rate is the effective spring rate when measured at the wheel. This is as opposed to simply measuring the spring rate alone.

Wheel rate is usually equal to or considerably less than the spring rate.

Cheers, Dave