<VV> Ackerman

[Mike Kost]

Padgett wrote:

> <SNIP> In Real Racing the ackerman is not that important since the 
> inside tire in a turn will have very little weight on it and tire wear 
> is usually not important. Besides the steering angles at high speeds 
> are small.
>
> In a low speed autocross where much wheel flailing may occur at low 
> speeds, the ackerman needs to be correct because scrub will increase 
> understeer and both front tires are having an effect, something you 
> really do not need. Repeat after me: "Upsetting the front end geometry 
> causes understeer". <SNIP>

I've been running IECO quick arms for about 25+ years and find that for 
most autocross courses the ackerman change makes little difference when 
I run 13" tires. If I run my street 14" tires (which likely have a 
little too much offset) the push is much more apparent. Just like was 
mentioned in road racing there are many cases in autocrossing when 
ackerman makes no difference since only the outside tire is in contact 
with the ground (many pictures to prove it). When set up properly the LM 
corvair (never dealt with an early) can be very neutral with 
controllable power on understeer and power off oversteer. Having said 
all of this I would love to have the ~3 turns steering I have now and 
not have the ackerman problem so that it would turn better in parking 
lots. I have noticed that a lot of newer vehicles (specifically our `99 
GMC Savana) have front end geometries that result in similar tire 
scrubbing on the outside tire in tight (parking lot) turns.

Mike Kost



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