Paul Foster wrote:
> I'm not sure if you can blame semi-trailing arm suspension. The early
> 911 (til 993??), 914, 924, 928, 944, and 968 all had the same
> suspension design without many tipovers...
Nonsense. I'm not intimately familiar with the 911, 924, 928, 944, or
968, but the 914 did not have semi-trailing arms.
It had true trailing arms. They run parallel to the car, and their
pivot was perpendicular to the car.
The BMW trailing arms (from the 1600's through E30 chassis) had semi-
trailing arms, in that the pivot was at 45 degrees to the axis of the
car.
I also don't know if this is a primary factor in the rollover rate;
after all, 2002's and 320i's don't have a high rollover rate. I think
it had something to do with the roll rate. They built up a lot of
angular momentum in roll, then abruptly hit the bump stops. The 318i,
I think, is worse in this respect than its E30 brethren, suggesting
that suspension settings (spring and roll rates, shock rates, ride
height) may be significant factors.
Still, to answer Peter's original question, I think I'd be afraid to
run any E30 chassis as a combination daily driver/autocrosser, and I
don't think it has much to do with tire choice or anything like that.
I'd certainly be inclined to run ridiculous shock and swaybar rates
in order to minimize roll rate, to minimize the impact on the bump
stops. But I scare easy. :-)
Mark
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