The semi trailing arm rear suspension is not all that bad if you
play with the pick up points. Toe change in bump can be used to help
turn in. The TR IRS has about 3" of good control of bump steer and
camber gain. The semi trailing arm worked well for BMW and Porsche. As
for switching to double a arm type of rear suspension, it won't pass the
SCCA Production Car Spec because if you add a suspension stabilizer
(control arm) you must be able to remove it and not have the suspension
collapse. That is the test we use to determine if the type of suspension
has been changed - ie - strut, double a arm, swing arm, semi trailing
etc. I have looked at the PCS for years and discussed it with other
scrutineers and I can't find a creative interpretation yet to allow the
double a arm rear. The PCS is pretty liberal these days and you can
generally drive a truck through the loopholes but this one is pretty
well written.
Greg Lund
|