[QUOTEThis may seem ignorant but (and maybe i should have read the whole thread) whats the idea of this mod? my car is lowered 30mm, std bushs/ shox (for now) running 15" compo mo's...
i have nothing fouling suspension-wise at the front and virtually no under steer (rear does the work)
wot gives
][/quote]
What about bump steer?
Look at the angles on your upper & lower A arms.
With the lower arm angled up you have lost the benefit of the unequal length A arm design, and as well, lost wheel travel.
The proper position for the lower arm is parallel to the track/road surface.
By lowering the car using dropped spindles there are at least three benefits.
One, simply is no loss of wheel travel & compliancy.
Another ,key benefit, is a longer(taller) spindle carrier(upright). (remember the knuckle risers on early 101 & 105 racecars?)
This length (added to the bottom under the spindle) increases the angle of the upper "A" arms when the lower arm is still level, which results in more camber change per degree of wheel movement.
In rebound (bump or upward movement) which on track is caused simply by body roll entering and through turns, there is a significant increase in negative camber. Enough, that rather than then having "positive camber" and loss of the contact patch between the tire & pavement as with the stock design, You actually have enough negative camber gain, to not just offset the body roll`s resulting movement towards "positive camber" but have a slight increase in "negative camber" to give the tire a better footprint on the pavement.
As well, on the other side of the car, rather than the suspension leaving the inside tire at negative camber, the droop (downward movement) of the suspension results in the upper arms moving the top of the upright farther out, moving the tire into a "positive camber" position increasing that tire`s bite as well.
When a car is incorrectly dropped so that both upper AND lower arms are angled upward every movement of the suspension moves the tire in or out severly causing major bump steer. Under braking or bump, you get "toe out", exactly what you do not want. Under droop, you get "toe in" . On the track all this results in a car with unstable conditions under braking, and unresponsive turn in.
With dropped & longer spindles , with the steering arms returned to the correct position relative to the steering rack, and with some increase in the Ackernan angles (which I do when modifying the spindles & arms), you can set up the car with less overall negative camber, with "0" toe in or out, resulting in less drag, less tire wear, and still result with correct camber footprints under cornering on both sides of the front. As well, the Ackerman changes I make result in increased "toe out" when the wheel is turned off center giving better "turn in" response, when cornering.
Please contact me off thread about having these modifications made & I will be happy to respond.
By the way,I tried to make this simple enough for JJ & BS (who`s avatar gives us a clue), but it probably won`t be enough. Useless postings
guys!
