After not being completely satisfied with the previous suspension setup, this customer brought their R35 GTR in to see if we could make it a little bit more track friendly without losing the OEM damper adjustability that the car comes with from factory.
Whilst a lot of people who drive a track oriented street car would grin and bear the ride of stiff coil-overs, when a car comes from factory with three electronically adjustable damper settings all accessible from a switch in the cabin, you can see why that’s something you would like to retain.
Keeping all that in mind, the decision was made to fully rebuild the factory Nissan Bilstein suspension into fully adjustable coil-overs, keeping the variable damper control from inside the cabin whilst achieving the track capability of a fully adjustable coil-over.
Because Heasmans is a registered Bilstein service centre, we have the ability to pull the factory Nissan shocks apart to adjust the internals. Here we can see the shock being filled with Bilstein specified oil above the dividing piston. It’s then bled before it is sealed to make sure there are no air bubbles.
It may not look like much but this is the heart of the Bilstein Damp Tronic dampening system. Since we are able to disassemble these shocks, we can change the valving inside them to give different results for the settings the customer has at the push of a button inside the car.
Funny how a bunch of tiny little bits and pieces can drastically affect the performance of a vehicle to the point where it will completely make or break how it handles. Shims and pistons laid out ready for any changes to be made to alter the shocks performance once it all goes back together!
The Bilstein test unit in this photo is used to simulate the ECU on the vehicle through each of the three settings, while on-road conditions are simulated on the Shock Dyno to see how the shock behaves in each setting before it’s even installed on the vehicle.
When such an extensive job is carried out, it’s nice to be able to do any follow up services with a little more ease. Another small but important modification was swapping the crimped ends on the shocks to some in house machined units to make them a serviceable once again.
Weigh in time, each corner of the car sits on top of a separate scale in order to record the weights independently.
Finally the weights from each scale are transferred to the computer so they can be adjusted if necessary, this is essential as it’s where the balance of the car is altered to ensure that it handles at it’s best.
After a full suspension overhaul, the final product is a shock that retains the three settings for the variable dampers. The performance however, is totally different. Now being a fully adjustable coil-over, they will be just as happy at the track as they will be on the ride home, with the switch between comfort, sport and race mode still at the push of a button. As it turns out, although the original suspension was first removed to make way for a set of aftermarket coil-overs. The answer all along was to keep the factory suspension and just hand it over to Heasmans for a bit of track ready treatment.