Mk5 Golf Rear Shock/Spring Proper Adjustment

[sebas_thefish]

Recently switched to R5 Racing coilovers which have a height adjustable spring in the rear but also an adjustable length damper (Same design as BC Racing). Had a shop install them and they just set the shock length to the same as stock and set the ride height via the spring. Now the ride in the rear seems unusually firm even with the dampening set on it's softest, it just bangs and crashes like it's rock hard!


Is there a proper way of setting the rear shock length in relation to the rear spring height that they didn't do? The spring is also slightly loose when the car is jacked up with the rear wheel off the ground which doesn't seem right either.


I'm comfortable making the adjustments myself just need advice on if they've installed it wrong and how I can set it properly.


Pic of my setup:

[ProfessorExperimental]

Enquired with R5 yet?*

Without knowing anything about this particular product it's categorically Not Good to have the spring loose at full droop. Either wind the spring perch up or shorten the damper so you can't easily move the spring around by hand. To level the car you'll always need to measure the dampers, or a point on the axle carrier to a point on the body (though even that can be inconsistent side to side).

It also looks like you might have an adjustable swaybar: if so preload there can affect how the car sits when loaded (one corner higher etc.) so the shop might have unintentionally compensated for this with your spring length. Also No Bueno.

When setting damper/spring free lengths on systems like this make sure the damper has less free length than the spring has coil spaces, if your coil binds before your damper stops it that will Suck Hard, though at least with non-strut setups you won't jackhammer the top nut off your damper shaft.

Finally: check your pillow ball(s) are actually free to move, if they're stiff your damper will be getting extra friction damping and feel like it has no oil.

*Any suspension designer who says "dampener" instead of "damper" makes me suspicious unless there's considerable ESL-tolerance involved.

[sebas_thefish]

Enquired with R5 yet?*

Without knowing anything about this particular product it's categorically Not Good to have the spring loose at full droop. Either wind the spring perch up or shorten the damper so you can't easily move the spring around by hand. To level the car you'll always need to measure the dampers, or a point on the axle carrier to a point on the body (though even that can be inconsistent side to side).

It also looks like you might have an adjustable swaybar: if so preload there can affect how the car sits when loaded (one corner higher etc.) so the shop might have unintentionally compensated for this with your spring length. Also No Bueno.

When setting damper/spring free lengths on systems like this make sure the damper has less free length than the spring has coil spaces, if your coil binds before your damper stops it that will Suck Hard, though at least with non-strut setups you won't jackhammer the top nut off your damper shaft.

Finally: check your pillow ball(s) are actually free to move, if they're stiff your damper will be getting extra friction damping and feel like it has no oil.

*Any suspension designer who says "dampener" instead of "damper" makes me suspicious unless there's considerable ESL-tolerance involved.

Got it sorted[emoji106] l. Shop did install the rear wrong i.e. they didn't set the preload. Sorted it out myself easily and the ride is 100x better, feels normal now.

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