Coilover setup (spring perch height adjustment)
Posted: Mon Apr 21, 2014 8:25 pm
Well spent a few days setting up the BC ER Coilovers by first setting the optimum length then adjusting height by the spring perch.
First the FL coilover was removed because this one was where the rubbing on the inner guard happens. Note the BC ER's cannot be removed like normal when using the long bolt method because of the external canisters. The top hat has to be removed then it can be taken out from the bottom. Apart from that the long bolt method worked. Also found out that my tool kit did not have a 21mm spanner, sockets yes...
Then the spring was removed and the coilover set to full soft and reinstalled sans spring, bumpstop.
Without the wheel on, the suspension was jacked up to see when all the shock length was used. For my BC's this happened with 25mm not used. This was to be the target with the wheel on.
The wheel was then put on and jacked up again to see how much of the 25mm was used/not used. The base of the coilover was then adjusted as required. All up my coilover was 20 mm too short, hence the rubbing on the inner guard!
However I could only get 35mm remaining with the wheel hardover due to lack of adjustment to the length of the BC ER's. Not sure if this is typical of all BC's.
Prior coilover length was 415 mm. Adjusted final length 435mm and 127mm of travel. An extra 20mm, the previous setup was wrong!
The FR coilover was then adjusted to the same length. Based on the result I then adjusted the rears to their max length (lazy I know). One day I will do this properly...
The front coilovers were reassembled, however the 8kg springs were replaced with 9kg's.
Height and corner weights were done. This time it took 9 attempts to get it right, normally only takes 2 attempts. My other half got a little agitated being asked to help because of her weight. The car had ballast for the dif between her and my weight.
Start at the pinch welds (drivers weight, half tank fuel)
FL 138, FR 145, RL 124, RR 129, splitter 130, cross weight 49%
Final heights.
FL 126, FR 127, RL 129, RR 133, splitter 99, cross weight 49.5%
However, the front at full droop has the springs uncaptive by about 30mm so helper springs are needed. The rear, no problems.
I drove 400km today with a co worker who lead the way on his motorbike and the car felt awsome. The car had oversteer, but it was power too early type oversteer. There was no rubbing on FL. Not sure what it was, but the car was less harsh on the bumps but tight when pushing through corners and at speed. I'm very happy with the results and well worth the effort to do it this way!
The drive was from Blackwater to Sapphire, Clermont then back to Blackwater by Emerald. Note the availability of 98 is very limited! To should have topped up at Emerald on the way to Sapphire, I had to put 10 ltrs of 95 in at Clermont just for peace of mind. Between Sapphire and Clermont the road was twisty, fast, slow, tight corners, corners that tighten up, long sweeping corners, unfenced cattle areas, cattle grids mid corner, blind crests...
I will do a separate post of the fun part of the drive. However all up very happy with the way the car handled. Now just need to replace rotors/pads and re wire the guages and ready for time attack round 2.
If people have the time to set up their coilovers this way they will be rewarded.
A final note lowering ride height at a corner will decrease the weight at that corner and the diagonal opposite (this will explain why it required 9 adjustments all up). Also 2 turns of the spring perch is 3mm in height and 5 kg.
Photos to follow....
First the FL coilover was removed because this one was where the rubbing on the inner guard happens. Note the BC ER's cannot be removed like normal when using the long bolt method because of the external canisters. The top hat has to be removed then it can be taken out from the bottom. Apart from that the long bolt method worked. Also found out that my tool kit did not have a 21mm spanner, sockets yes...
Then the spring was removed and the coilover set to full soft and reinstalled sans spring, bumpstop.
Without the wheel on, the suspension was jacked up to see when all the shock length was used. For my BC's this happened with 25mm not used. This was to be the target with the wheel on.
The wheel was then put on and jacked up again to see how much of the 25mm was used/not used. The base of the coilover was then adjusted as required. All up my coilover was 20 mm too short, hence the rubbing on the inner guard!
However I could only get 35mm remaining with the wheel hardover due to lack of adjustment to the length of the BC ER's. Not sure if this is typical of all BC's.
Prior coilover length was 415 mm. Adjusted final length 435mm and 127mm of travel. An extra 20mm, the previous setup was wrong!
The FR coilover was then adjusted to the same length. Based on the result I then adjusted the rears to their max length (lazy I know). One day I will do this properly...
The front coilovers were reassembled, however the 8kg springs were replaced with 9kg's.
Height and corner weights were done. This time it took 9 attempts to get it right, normally only takes 2 attempts. My other half got a little agitated being asked to help because of her weight. The car had ballast for the dif between her and my weight.
Start at the pinch welds (drivers weight, half tank fuel)
FL 138, FR 145, RL 124, RR 129, splitter 130, cross weight 49%
Final heights.
FL 126, FR 127, RL 129, RR 133, splitter 99, cross weight 49.5%
However, the front at full droop has the springs uncaptive by about 30mm so helper springs are needed. The rear, no problems.
I drove 400km today with a co worker who lead the way on his motorbike and the car felt awsome. The car had oversteer, but it was power too early type oversteer. There was no rubbing on FL. Not sure what it was, but the car was less harsh on the bumps but tight when pushing through corners and at speed. I'm very happy with the results and well worth the effort to do it this way!
The drive was from Blackwater to Sapphire, Clermont then back to Blackwater by Emerald. Note the availability of 98 is very limited! To should have topped up at Emerald on the way to Sapphire, I had to put 10 ltrs of 95 in at Clermont just for peace of mind. Between Sapphire and Clermont the road was twisty, fast, slow, tight corners, corners that tighten up, long sweeping corners, unfenced cattle areas, cattle grids mid corner, blind crests...
I will do a separate post of the fun part of the drive. However all up very happy with the way the car handled. Now just need to replace rotors/pads and re wire the guages and ready for time attack round 2.
If people have the time to set up their coilovers this way they will be rewarded.
A final note lowering ride height at a corner will decrease the weight at that corner and the diagonal opposite (this will explain why it required 9 adjustments all up). Also 2 turns of the spring perch is 3mm in height and 5 kg.
Photos to follow....
. The external canisters are not important, rather the separate rebound setting is.
