Hope you don’t mind us popping in but someone told us there was a tech question re the anti-dive kit and suggested we might be able to help.
The KCA305 ADK is designed to perform 2 separate functions but both related to front handling performance outcomes. The most unconventional is the anti-dive or anti-lift kit (really the same thing) that works to remove the stock anti-geometry that the engineers built in for a more benign and less responsive front end.
It’s a function of weight distribution and throttle steer and by changing the location of the control arm pickup point via a revised mount bracket we allow the front suspension to respond more directly to changes in driver throttle input. This leads to less understeer and more direct steering response under braking and acceleration and makes it more responsive overall. The use of a low compliance engineered poly bush helps to reduce the difference between dynamic and static alignment behaviour which in plain English means trying to make sure that the changes we build in don’t get moved around when things get serious on the track or street.
Which leads to the next part as dynamic behaviour is particularly important for caster loss.... or lack of. You see, it’s not so much the absolute positive caster you get that matters as how much you’ve got left when you need it. The benefits of higher positive caster are pretty obvious now but the value starts to evaporate as you brake coming into the corner.... just when you need that extra caster for better turn-in and corner bite. Hence why the +1.0 degree extra caster built in to the kit when on the wheel aligner actually delivers close to an extra +2.0 on the road as the bush and revised mount hold it closer to the designed amount.
Well all that is well and good and low compliance means less comfort. Yes and no and that’s where we work really hard to try to minimise the difference. In fact, we think we’re pretty good at by now as we’ve been doing this sort of part for over 10 years now and we like to think that the compromises aren’t too bad.
Anyway, hope that helps explain some of the stranger stuff about this part and what it actually does. Very happy to answer any more question about this but in the meantime you might like to have a look at the this thread on www.racedotcom.com
to read a little more about “anti” geometry in general and how it can be used to help performance handling http://www.racedotcom.com/showthread.php?t=27437