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[Continuing from here: http://www.reallymeansounds.com/for...princess-update-post-99-outdoor-carcoon.html] ]
After we lost Ian Bishop, it has got hard to get a proper set-up. Those who are able to are either too busy, or in the sticks, or both.
So I decided to have a go myself. After all, how hard could it be
If anyone has done this before, please have a look through this description and tell me what I missed or got wrong
As a first step I have spent half of Friday, and all Saturday, adjusting ride height. Needed to get the back lower, and it was a good time to get the whole thing balanced up again as well.
It involves a lot of raise car, wheel off, twiddle height, wheel on, lower car, measure, repeat. Proper workout!
1. Load up driver's seat with a turnip simulator
Technically it should have been done at half tank, but
it happened to be full. Tank is pretty much in the centre,
so the extra weight matters more for toe than ride height/
corner weights.
2. Calculate the nominal distribution:
Weight: 755kg
Distribution: 40/60 front/rear
Driver weight: 90kg
Hence:
Total weight: 845kg
Front left: (755/2)*0.4=151 => 45% right/left
Front right: (755/2 + 90)*0.4 = 187 => 55% right/left
Rear left: (755/2)*0.6=226.5 => 45% right/left
Rear right: (755/2 +90)*0.6 = 280.5 => 55% right/left
3. Measure current:
Ride height:
Front right: 105mm
Front left: 110mm
Rear right: 130mm
Rear left: 125 mm
4. Goal:
Front: 105-110, rear: 115/120 (front+10)
5. Adjust ride heights, and get roughly even side to side
6. Measure corner weights, and fine tune ride height to
get to nominal distribution front/back and side/side
7. Final readings:
Ride height:
Front: 109mm
Rear: 118 mm
Would have liked it a little bit lower, but that would
have left the springs loose at the rear at full droop
(about 1/2" at 110-115 rear height). Lotus wisdom seems to
suggest this would still be ok in practice, but technically
an MOT failure. Though I have never seen the wheels off
the ground at an MOT.
Anyway, left the rear ride height where the springs are still held
at full droop for now. Checking with Nitron if helper springs are
needed to go lower.
Final distribution:
43/57 front/rear
46/54 left/right
7. Have a strong cup of tea and a lie-down, phew
Next: Toe and Camber...
The turnip simulator - a few bags of sand. About the same IQ
Corner weight gauge. Theory is you take a reading when you can just slip a card under the wheel. Reading in this one happens to be PSI/Bar, but unit does not matter as one is adjusting against relative percentages, not the absolute readings.
Absolutely invaluable tool! Found it by pure chance the other day. No chance in hell of fitting a c-spanner in here
Oddly, there is no lockring on the Nitrons. Apparently as it should be. In fairness, they have never moved in the two years they have been on the car now.
Measuring front ride height off the front edge of the side chassis rail, inside the front wheel arch.
Measuring rear ride height. Bleedin' undertrays have to come off as ever to get at the rear edge of the side chassis rail.
After we lost Ian Bishop, it has got hard to get a proper set-up. Those who are able to are either too busy, or in the sticks, or both.
So I decided to have a go myself. After all, how hard could it be
If anyone has done this before, please have a look through this description and tell me what I missed or got wrong
As a first step I have spent half of Friday, and all Saturday, adjusting ride height. Needed to get the back lower, and it was a good time to get the whole thing balanced up again as well.
It involves a lot of raise car, wheel off, twiddle height, wheel on, lower car, measure, repeat. Proper workout!
1. Load up driver's seat with a turnip simulator
Technically it should have been done at half tank, but
it happened to be full. Tank is pretty much in the centre,
so the extra weight matters more for toe than ride height/
corner weights.
2. Calculate the nominal distribution:
Weight: 755kg
Distribution: 40/60 front/rear
Driver weight: 90kg
Hence:
Total weight: 845kg
Front left: (755/2)*0.4=151 => 45% right/left
Front right: (755/2 + 90)*0.4 = 187 => 55% right/left
Rear left: (755/2)*0.6=226.5 => 45% right/left
Rear right: (755/2 +90)*0.6 = 280.5 => 55% right/left
3. Measure current:
Ride height:
Front right: 105mm
Front left: 110mm
Rear right: 130mm
Rear left: 125 mm
4. Goal:
Front: 105-110, rear: 115/120 (front+10)
5. Adjust ride heights, and get roughly even side to side
6. Measure corner weights, and fine tune ride height to
get to nominal distribution front/back and side/side
7. Final readings:
Ride height:
Front: 109mm
Rear: 118 mm
Would have liked it a little bit lower, but that would
have left the springs loose at the rear at full droop
(about 1/2" at 110-115 rear height). Lotus wisdom seems to
suggest this would still be ok in practice, but technically
an MOT failure. Though I have never seen the wheels off
the ground at an MOT.
Anyway, left the rear ride height where the springs are still held
at full droop for now. Checking with Nitron if helper springs are
needed to go lower.
Final distribution:
43/57 front/rear
46/54 left/right
7. Have a strong cup of tea and a lie-down, phew
Next: Toe and Camber...
The turnip simulator - a few bags of sand. About the same IQ
Corner weight gauge. Theory is you take a reading when you can just slip a card under the wheel. Reading in this one happens to be PSI/Bar, but unit does not matter as one is adjusting against relative percentages, not the absolute readings.
Absolutely invaluable tool! Found it by pure chance the other day. No chance in hell of fitting a c-spanner in here
Oddly, there is no lockring on the Nitrons. Apparently as it should be. In fairness, they have never moved in the two years they have been on the car now.
Measuring front ride height off the front edge of the side chassis rail, inside the front wheel arch.
Measuring rear ride height. Bleedin' undertrays have to come off as ever to get at the rear edge of the side chassis rail.
