Quote:
Originally Posted by stonenewt
On the smooth surface sections the Twin was really good, felt absolutely planted & was very adjustable. Very close to the Cayman in terms of grip & handling ability, I think the Cayman was on PSS not PS2! However on the sections of the track with rough or uneven surfaces I was left with the GT86 skipping off the top of lumps & bumps. On those surfaces the Cayman absolutely destroyed the GT86 due to its composure, the Porsche was also a lot more comfortable in the cabin.
This tells me that fundamentally the Twins are 90% there in terms of a Cayman equivalent chassis but the suspension is lacking in the spring/damping balance compared to a PASM chassis. From what I’ve read the problem lays in the damping being too strong & not letting the wheel move fast enough. So the first order of business with the car is to sort the damping/ spring synergy out which means you do one of two things
1) Get slower/weaker dampers to allow for faster wheel movement.
2) Get stronger springs to allow for faster rebound reaction.
While it maybe cheaper to ‘fix’ the spring weight to get the better movement I think a PASM Cayman will ace a stiffer Twin on UK back roads. So you’re looking at the more expensive route of sorting the damping. Normally I’d head for Bilstein B4 dampers, but it doesn’t seem they exist for the Twins so maybe the B6 dampers.
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1) Correction... it needs weaker/less/looser compression damping force under fast speed damping (bumps, rumble strips, quick jars, etc.), but still strong/more/stiff damping force under slow speed damping (turns, braking, accel, straights)
2) Correction... it needs more rebound damping under fast speed damping to compensate for post bumps and to recover after a bump and set the tire back into the road for traction.
Correct me if I'm wrong though.