Post 106 "Setting up the coilovers correctly" was abit over a year ago when I removed the coilovers to reset them, and setup the correct way along with a 20kg front spring to replace the current 14kg spring at the time. You can refer to that post for all the details, but I'll mention some of it here for context of what I did today.

TLDR; I made a mistake with my understanding of how to set the ride height with the lower spring seat & spring, then trying to add a helper spring to cater for my mistake (not knowing it was a mistake). I couldn't understand why the front had a wheel gap of 20mm-30mm, so with a few days left before Morgan Park, Grant's quick and cheap suggestion (with the quick minimal info I gave him) was to remove the spring seat lock ring to lower the unit and it worked. I would lose the adjustability of the height, but I was rushing to get it to the track.

I've driven the past year with the front at that height, but with fitting my new 9" 6UL's fronts, I needed to raise the car.

After asking Grant for some assistance, I ran my understanding past him so we could identify where I went wrong, understand, and correct it. With additional guidance, I refitted the spring seat lock ring and went through the process again but with some different steps.

The outcome, the front is now setup correctly to utilise full travel of the shock, taking into considering the droop, bump and ride height, running the numbers to make sure everything is micky mouse with one another, and I now have the ability to adjust the height again. Full droop sees 5mm gap with an uncaptive spring, which is within the ok range, I would like to lower it, so I might work a shorter spring + helper spring into that solution.

Once again, thanks heaps Grant! Make sure to check them out, not just for parts but also for the education material, so you can set up your suspension correctly!

Steps

In short:

1. Set body length for target droop
   • Without spring
2. Check bumpstop engagement point, add spacers if needed
   • Or cut down bumpstops
3. Set ride height

In depth:

1. Remove the spring and dust boot for visibility of the bumpstop, and refit the top hat assembly,
2. Car on jackstands, refit coilover and wheel to the car
3. Set the droop

• Jack up suspension to desired ride height, 295mm for me, measuring from centre of the hub to the edge of the wing (or measure from bottom of the rim as it's easier, and minus half the wheels diameter)
• Then drop the jack to get full droop of suspension, measure the full droop height now
• Subtract the droop from ride height, and this should ideally be >= 50mm
  • IF adjustments are required, turn the lower mount to adjust the body length
  • Note In my case due to the external reservoir would hit the lower mount at 45mm, so I've maxed out at 44mm droop

4. Set full bump

• Now jack up the suspension until the bump stop is pushed up against the top hat, measure the full bump height now
• Subtract the ride height from full bump, and this should ideally be >= 30mm
  • IF adjustments are required, change or cutdown the bumpstop, or add spacers
  • Note In addition to setting this, turn the wheel full lock to full lock, ensuring the wheel doesn't foul on the body. Adjust if required

5. Set ride height

• Remove coilover, refit the spring correctly, refit to car with wheel
• You'll now need to jack the car onto the ground to measure the ride height under load
• To adjust, turn the spring seat lock ring as required to achieve the desired ride height, which means jacking it back up to turn

6. Check uncaptive spring

• Jack up the car to allow full droop and check if the spring becomes uncaptive (loose)
• Depending on coilover design, you ideally don't want no more than 15-20mm gap if you push the spring up and measure from the bottom of it to the spring lock ring seating position.
• IF theres too much, you'll need to either get shorter springs and/or use helper springs.

Confirming the final measurements:

• Take the droop, full bump and ride height, then try the below for the ideal setup
  • Full droop - ride height >= 50mm
  • Ride height - full bump >= 30mm

The procedure (with some photos)

Here is the current state of my setup mentioned to start with. Remove spring and reassemble.

Droop set, this is the external reservoir issue I had

Full bump then set, the first photo is with the bumpstop just touching the top hat, second photo is with the bumpstop compressed as much as possible. With the spring fitted, it's extremely unlikely I'll ever be in such a compressed state where the bumpstop would compress. So I'm fine with the tyre touching wing on bumpstop compression

With ride height set (photos futher down), a quick check on the uncaptive spring. You'll notice the black plastic guard behind it, a nice feature on my BC coilovers to stop the uncaptive spring from moving around too much

Before and after comparison

The final product

How the ride height looks, quite presentable!

Some all round photos

With all that done, usual wheel alignment things, and we're sorted!