Thursday, August 10, 2017

Damper set up

Andy at GD will set up your new GD suspension at no additional cost. My car is a Euro so should only need the dampers setting, as the rest is set as part of the rolling chassis build. The car drives well now, but does 'float' a little over crests in the road and also feels a little unstable particularly at speed on the motorway, which does not instil total confidence when pushing on. The dampers (or shockers) control oscillation of the springs and keep the tyres in contact with the road. So this is what I needed to sort out to address the minor handling issues.

I didn't really want to take the car to the factory, as it is a 2.5 hour drive each way and I have no weather gear to combat the vaguaries of the British summer. A quick call to Andy and he explained the way to adjust the dampers and that it should correct the issues above. The dampers are set using just one knob for both the compression and rebound. If I made a pigs ear out of it, there is no real harm done as it can be corrected!

Andy knows the feel of the cars and the changes needed to correct the symptoms. It also depend on the weight of the driver, passenger and junk/tools etc carried in the boot (if a lot of weight in the boot you may need more clicks at the rear). He suggested that damper settings of around 4-6 clicks clockwise are likely to be about right, but that I may need to amend this to my preference. No change is required to the spring rates or toe. However, for the track more clicks may be required e.g 12/13!

The first job is to set the ride height. Mine is set to clear local speed bumps (see a previous post).

Collar for ride adjustment can be seen here
This is achieved by adjusting the collars up (using a C spanner) at the bottom of the springs.
The lower the car the less it will roll in corners (lowers the centre of gravity) and the better it will handle, but the car is more likely to come into contact with speed humps (legal limit for a speed bump on a public road is 4" I think) or raised road surfaces/metalwork - so you have been warned!

Next I needed to back off all four dampers fully (they were set to 5 clicks at the factory) - turning the knurled knob fully anti-clockwise, so that the knob will not turn any further (don't force it). You should be able to do this with the wheels on. The knobs are at the bottom of the dampers - on the inside at the front and on the leading edge at the rear.
Front nearside damper knurled knob (faces away from wheel)

Rear nearside damper knob (faces front of car)
Then turn the knob, say 6 clicks clockwise (which is one full rotation of the knob). For road use/touring you do not want the car to be too stiff or it will be uncomfortable and thump over every road imperfection. I set mine to 6 clicks. With 7 clicks it handled well but was a tad too hard. If you have a roll bar fitted the setting is likely to vary

Now the good bit. Once adjusted, test the car on your favourite road 😆. If it is not quite right, further adjustments can be made. Extra clicks will firm up the dampers, backing it off will reduce the damping effect. Note, this is not the spring rate, but the speed at which the dampers move and allow the car to roll in corners, control the car over undulations and dive (or not) under braking.

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