914 Suspension motion ratios, Comparing notes Options

[groot]

I measured my front and rear motion ratios yesterday and wanted to compare notes with any that have done the same.

For the rear suspension I took ~20 data points and did a best fit analysis to come up with 1.00 to 1.00 damper travel to wheel travel with strong statistical correlation.

My front geometry is a bit different than a standard 914, so the motion ratio should be different, too. I measure ~10 points and found 0.83 damper travel to wheel travel, again with strong statistical correlation.

I'm about to order my rear shocks and this is one of the bits of data they need to build the shocks.

[slivel]

Additionally this may change the roll center but doesn't this now cause the arc of the wheel to be other than vertical under suspension travel?

Steve

The wheel travel is never strictly vertical because the lower control arm pivots about a point. The shorter the control arm, the more track change you get during the suspension travel.

Yea, that makes sense. In my case using stock arms I am probably better off not mucking with trying to change the roll center without changing the pickup points.

From the pics in the earlier thread - you certainly did make some "minor modifications". I don't think that I can go that radical with the rules in the clubs that I run. I am a fairly experienced club racer (10 years) but only recently have started to seriously think about chassis and suspension tweaks. Thank you for your informative posts.

Steve