Vehicle Ride height

[Tango]

Before I dropped my Lexus IS250 the clearances between the top of the tyre and wheel arch front and rear were approximately the same, possibly slightly more clearance at the front than the rear. This changed after fitting the American specification Eibach springs as they lowered the car 0.5" more at the front.

 

Before lowering:

 

After:

 

 

I didn't notice any problem with the handling, but as the springs and wheels (plus the WIM geo) also improved it considerably I find it difficult to say the lower front end changed anything at all.

 

No doubt peeps are wondering why I've raised the point, well I've noticed that the IS-F has an even more pronounced bias in that the front has a lot more clearance between the tyre and arch at the front than the rear.

 

 

So, are there valid reasons why a car should be set up with more clearance/raised ride height at the front than the rear or vice versa? I understand that setting the front to be 0.25" or 0.50" higher than the rear (-ve rake angle) gives better traction out of a corner, is this down to weight transfer?

[Tony]

Good question.......

 

Many reasons for the rake bias, namely weight transfer under braking, diagonal transfer during yaw while on a lock and as you say maintaining the contact patch during suspension bump.

[Kozy]

Good question.......

 

Many reasons for the rake bias, namely weight transfer under braking, diagonal transfer during yaw while on a lock and as you say maintaining the contact patch during suspension bump.

 

Strange, I always thought cars were best off with a positive (nose down) rake angle, certainly for aero at least. But then I am used to FWD shopping cars so that may sway things a tad...