Discussion
Can anyone explain the 'why?' of zero droop for me, please?
I'm studying suspension, and receive the lesson to adjust (an FF in our workshop) for zero droop, front and 20-30mm droop back. I can't understand why, in corners, and the explanation is something like - it lets you go faster - which isn't an explanation.
I think I can understand this in a straight line start; as the car accelerates, weight transfers to the rear and the front lifts. If the suspension will not droop, then the weight transfer is limited, until the rear tyre reaction is so great as to lift the whole front end of the car. The tyres remain on the road as far as possible and steering is maintained.
But cornering? Weight transfers to the outer wheel, and that side of the suspension compresses, while the inner side would move into droop as the car rolls. But it can't, because it's already in zero-droop.
To me, and because the side forces are not lifting the whole car's front but only one corner, this would cause the typical Mini cornering stance, with the inner front wheel in the air, with no traction/grip at all.
Understeer is inevitable, but I am assured that this will keep the inner wheel on the ground, with little weight on it, to be sure, but enough to help prevent understeer.
As for rear droop at such a small figure - Gok!
I'll be grateful for some discussion.
John
I'm studying suspension, and receive the lesson to adjust (an FF in our workshop) for zero droop, front and 20-30mm droop back. I can't understand why, in corners, and the explanation is something like - it lets you go faster - which isn't an explanation.
I think I can understand this in a straight line start; as the car accelerates, weight transfers to the rear and the front lifts. If the suspension will not droop, then the weight transfer is limited, until the rear tyre reaction is so great as to lift the whole front end of the car. The tyres remain on the road as far as possible and steering is maintained.
But cornering? Weight transfers to the outer wheel, and that side of the suspension compresses, while the inner side would move into droop as the car rolls. But it can't, because it's already in zero-droop.
To me, and because the side forces are not lifting the whole car's front but only one corner, this would cause the typical Mini cornering stance, with the inner front wheel in the air, with no traction/grip at all.
Understeer is inevitable, but I am assured that this will keep the inner wheel on the ground, with little weight on it, to be sure, but enough to help prevent understeer.
As for rear droop at such a small figure - Gok!
I'll be grateful for some discussion.
John
It's for traction. If you have zero droop on the front any acceleration will make the front will ride on the droop stops. On corner exit when accelerating it stops the inside front taking any weight off the inside rear which needs it more in a rear drive single seater during this phase. This is because with the roll and pitch at this phase of the corner the inside front will not press down on the track as there is no droop leaving the inside rear to carry the weight of the inside of the car.
When de-accelerating the front suspension works normally as it will be compressed away from the zero droop position. Contrarily the rear droop stops work in this phase by stopping the rear from overshooting the normal ride height the rear would run at under braking. It also means there may b more weight transfer at the rear during the braking and turning in as the inside rear may be at full extension. It's a bit like having stiff rebound dampers on the rear but more s
t. You're better having more rebound damping than rear anti-droop I reckon anyway. During acceleration the rear droop stops do nothing as the rear suspension is compressed.
There is a slight disadvantage to anti-droop on the front when it's bumpy as you can lock the front wheels up more easily.
When de-accelerating the front suspension works normally as it will be compressed away from the zero droop position. Contrarily the rear droop stops work in this phase by stopping the rear from overshooting the normal ride height the rear would run at under braking. It also means there may b more weight transfer at the rear during the braking and turning in as the inside rear may be at full extension. It's a bit like having stiff rebound dampers on the rear but more s
t. You're better having more rebound damping than rear anti-droop I reckon anyway. During acceleration the rear droop stops do nothing as the rear suspension is compressed.There is a slight disadvantage to anti-droop on the front when it's bumpy as you can lock the front wheels up more easily.
Running our FF1600 we would run up to 3 turns of the spring platform above zero droop. Could never get a sensible explanation of how it worked other than the car went faster. It won the 2014 National Championship for Kent FF1600 and finished on the podium at the FF Festival 3 years on the trot, so clearly worked....
Springs,.. a very black art.
Springs,.. a very black art.
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