Transition 4: Cayman to Caymonster

Porsche Cayman S

With all the old parts removed, it was time for the new parts to be fitted and the set-up to be completed. The results were impressive, to say the least.

As is always the case when working on something that is not box-fresh, the Cayman had some minor issues that Chris at Centre Gravity had to work through to get the new top mounts and coilovers fitted. The rear disks didn’t want to come off because the handbrake shoes were caught behind a lip on the inside of the disk bell, and whilst fixing that problem the handbrake cable came unhooked from the handbrake mech in-cab so the centre console had to be removed to re-attach it.

None of these issues were major, but they were still an inconvenience. One of the bushings had also started to delaminate from one of the control arms, so while the suspension was apart that got replaced too. It's a common fault on these cars, apparently. Once all the niggles were addressed, and with a few hours under his belt, Chris got the suspension back together and the real work of getting everything dialled in was about to begin.

The black art of chassis tuning

First things first: how much do I weigh… wait, what? Why could you possibly need to know my weight, Chris? That's rather personal! Well yes, but it's also crucial to getting the car perfectly set up. All settings and measurements are made with weights on the driver seat and a full tank of fuel so that the car is as close to road-going spec as possible.

Next up, the ride height and the corner weighting. To be honest, I had no idea what corner weighting was prior to meeting Chris, but basically it means that the weight distribution of the car is symmetrical across the car. This affects the consistency of the car when turning left and right. By adjusting the spring perches on each shock and using corner scales Chris can balance the car from side to side, just like you would a snooker table with adjustable legs.

A car that is not properly weighted will feel different on turn-in one way than it does the other, which is not a nice feeling! The adjustable coilovers were set to combine the correct ride height (we went for a GT3 ride height that was actually a couple of mm over the suggested maximum ride height of the PSS9 kit, but this car is being used on the road!), a slight nose-down stance, and (this is the important part) symmetrical weight distribution across the car.

With the ride height and weighting done, all the other geometry could now be set. Toes, cross-toe, camber, caster, thrust - there are just too many combinations and setting to name! When you take it to the nth degree as Chris does, it gets even more complex since you have to consider things like compound caster that varies with both steering angle and caster angle! It’s no wonder that chassis tuning is considered to be a black art….

However, just throwing a load of settings at a car is not what happens here. The starting point for each car comes from a great understanding of how suspension works and how a car will react to adjustments of each individual parameter. Settings are added on the incredibly accurate Beissbarth machine, which is constantly monitored and calibrated for accuracy. After each set-up, the car is taken out on a circuitous route and each aspect of the car's handling is assessed. After every drive, the car comes back, has the settings checked and any necessary adjustments made.

To give you an idea of the level of accuracy that is trying to be achieved, my particular car had four separate trips to the Beissbarth machine! Initially this is done by Chris alone, in an attempt to imbue the car with the characteristics that the customer had been originally requested by the customer. Only once he's happy with the feel and handling of the car, and is getting repeatable results from the laser alignment machine, is he ready to let the customer drive it. They are invited to drive the same route and asked to offer comments and feedback on the settings that have been selected.

The first post-tuning drive

That first drive left me feeling a little shocked. Shocked that what I had previously thought to be a car with outstanding handling could have been so positively transformed. Sure, there are equal measures of brilliance in the shocks, the top mounts and the overall tuning of the system, but the simple reality was that the car rode better, turned in sharper, had far tighter control over its wheels, had massively more grip both at the front and the rear, and transmitted more of the detail of the road through the car to my seat.

More incredibly, it did this without feeling aloof, without dragging me around the road tramlining and bump-steering into oblivion, and most importantly, without feeling dangerous. It had the same beautiful benign balance that allowed you to take liberties without the car wanting to kill you. It just felt so "right", in every department.

To say I drove away from Centre Gravity a happy man would be an understatement. When I put the Cayman through its paces on the track the following week, in less than ideal conditions, that feeling was only reaffirmed. Without a doubt, the decision to change the suspension and have Chris do the install and set-up of the car was one of the best of my motoring career to date.

Admittedly, it wasn’t a cheap affair, but then having seen the level of detail and precision that goes into every set up at Centre Gravity, I consider it a more than fair price. That the resultant set-up saw the track life of the tyres more than double, even with the far faster laptimes that were now achievable, was an added bonus that make the decision even easier to justify.

But this isn’t the end of the Caymonster story! Oh no! There is yet more to come...