[Tom Wells]

Salt,

Don't know the answer directly, but I can dance around it a little ;-)

I use four Aldan PAS 654 rear shocks on my XJS rear axle, using 3.8S length swing arms and axles (longer than XKE but way shorter than XJ6.) I do think they're good shocks. They've needed rebuilding twice in 40K+ miles.

They work well for my E-M which is perhaps fairly similar to your Contemporary. Kinda depends partly on your rear axle/swingarm specs too.

When I first put the car on the track at Summit Point the builder used a shock that was too short; the interesting symptom was that when I was coming into the front straight at decent speed and cornering fairly hard, the car skipped sideways. Unsettling for me and for the car. The rear of the car literally bounced toward the outside of the corner.

The short answer is that longer shocks with a bit more travel eliminated the skipping.

My analysis was that when the car rolled a little the inside wheel unloaded and came clear of the road. As the outside tire slid the inside tire would try to bite again. Whether that's correct or not the newer shocks (same as the Aldans you noted above) seemed to eliminate the skipping. Many more track miles on many more tracks - no skipping - so I think the problem was solved.

The shorter stroke shocks may give you a similar result - or not! It depends on whether they are acting to lift the inside wheel in a turn as they get to the end of their extend stroke while the car is rolling, and on other factors such as roll bars, tires, weight distribution etc etc.

As you can tell, I'd choose the longer stroke shocks. Brand may not matter as much: QA1, Koni, Aldan and others may all give you an OK result.

Hope this helps and doesn't confuse,

Tom