alignment.....WOW!
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Joined: Oct 2000
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From: Rochester, NY
Originally posted by Mrsideways
I got Bill gendrons alighnment right now and it was a bit of a Oversteering nightmare. It was quick but a bit tricky to control.
I got Bill gendrons alighnment right now and it was a bit of a Oversteering nightmare. It was quick but a bit tricky to control.
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Joined: Oct 2000
Posts: 167
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Rear toe in the S.
Here's my theory. I have not taken a bump-steer gauge to the S, but I am assuming that the rear suspension toes-out as it compresses. If that assumption is acceptable then, you should look at toe in relation to body roll. In a turn one side compresses and the other side droops. Another way of looking at it, one side toe-out and other toes-in. More body roll, more toe changes. What do you have? Essentially the rear wheels steering out of the turn, passive 4-wheel steering. Sounds really nice but introduce a mid-corner bump or an abrupt mid-corner correction and you're toast. This is called roll-steer. Its usually a big NO-NO.
In order to keep the car predictable and stable you need to control roll, especially the rear. Not too much, Not to little, just right. That's the problem, its too picky. Honda's been playing with the spring/bar combo trying to find a decent compromise. That's why we have a huge rear bar that tends to pickup the inside rear. However, picking up one tire is better than both rear tires steering you into the gravel.
I believe that is the one of the reasons the use of a big @$$ wing is very effective. Not only does it negate the lift, it also keeps the roll to a minimum. In fact, if you use a big wing, you can employ a softer rear bar, so that in slow corners you can take advantage of the rear suspension's "steering" abilities.
Progressive springs are effective too, as it allows the initial compression of the suspension, however doesn't let it go too far. Lowering the rear helps too, as long as you've got enough suspension travel to allow for massive front-rear weight transfers and have some headroom for those unavoidable mid corner bumps.
Until Ultimate Lurker, comes up with his 11,000 RPM, 350HP F20C, I'm going to keep her fairly stock. 240 ain't enough. Besides I have better uses for my car.
Here's my theory. I have not taken a bump-steer gauge to the S, but I am assuming that the rear suspension toes-out as it compresses. If that assumption is acceptable then, you should look at toe in relation to body roll. In a turn one side compresses and the other side droops. Another way of looking at it, one side toe-out and other toes-in. More body roll, more toe changes. What do you have? Essentially the rear wheels steering out of the turn, passive 4-wheel steering. Sounds really nice but introduce a mid-corner bump or an abrupt mid-corner correction and you're toast. This is called roll-steer. Its usually a big NO-NO.
In order to keep the car predictable and stable you need to control roll, especially the rear. Not too much, Not to little, just right. That's the problem, its too picky. Honda's been playing with the spring/bar combo trying to find a decent compromise. That's why we have a huge rear bar that tends to pickup the inside rear. However, picking up one tire is better than both rear tires steering you into the gravel.
I believe that is the one of the reasons the use of a big @$$ wing is very effective. Not only does it negate the lift, it also keeps the roll to a minimum. In fact, if you use a big wing, you can employ a softer rear bar, so that in slow corners you can take advantage of the rear suspension's "steering" abilities.
Progressive springs are effective too, as it allows the initial compression of the suspension, however doesn't let it go too far. Lowering the rear helps too, as long as you've got enough suspension travel to allow for massive front-rear weight transfers and have some headroom for those unavoidable mid corner bumps.
Until Ultimate Lurker, comes up with his 11,000 RPM, 350HP F20C, I'm going to keep her fairly stock. 240 ain't enough. Besides I have better uses for my car.
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Joined: Dec 2000
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From: San Diego
No, no, no...
You want to keep the big rear bar when going with a wing. Without it, the car will push like a pig in the slow corners. Keeping the big bar allows the car to be a little loose and rotate well for the tight low-speed stuff, then as speeds pick up the rear wing gives extra grip to provide stability and balance things towards understeer. The big bar also keeps the rear from rolling too much and minimizes whatever toe change is present in the suspension design. The S2000's rear suspension, while not perfect, is pretty darn good in this regard. When you're pushing at 10/10ths you just can't do things like "abrupt mid-corner corrections" and expect some sort of magical suspension design to save you.
A wing does nothing to affect body roll - if anything, it makes the car roll more. The extra available grip leads to faster cornering and greater lateral weight transfer - resulting in more body roll.
No real racecar uses progressive rate springs. Rising rate geometry, maybe, but the springs will be linear. The extra variable causes unpredictability as the suspension moves through its range of motion. Fine for a street car though.
With only 240hp, S2000 owners needn't worry about any "massive front-rear weight transfers"...
[QUOTE]Originally posted by BBSpoon
[B]Rear toe in the S.
Here's my theory. I have not taken a bump-steer gauge to the S, but I am assuming that the rear suspension toes-out as it compresses. If that assumption is acceptable then, you should look at toe in relation to body roll. In a turn one side compresses and the other side droops. Another way of looking at it, one side toe-out and other toes-in. More body roll, more toe changes. What do you have? Essentially the rear wheels steering out of the turn, passive 4-wheel steering. Sounds really nice but introduce a mid-corner bump or an abrupt mid-corner correction and you're toast. This is called roll-steer. Its usually a big NO-NO.
You want to keep the big rear bar when going with a wing. Without it, the car will push like a pig in the slow corners. Keeping the big bar allows the car to be a little loose and rotate well for the tight low-speed stuff, then as speeds pick up the rear wing gives extra grip to provide stability and balance things towards understeer. The big bar also keeps the rear from rolling too much and minimizes whatever toe change is present in the suspension design. The S2000's rear suspension, while not perfect, is pretty darn good in this regard. When you're pushing at 10/10ths you just can't do things like "abrupt mid-corner corrections" and expect some sort of magical suspension design to save you.
A wing does nothing to affect body roll - if anything, it makes the car roll more. The extra available grip leads to faster cornering and greater lateral weight transfer - resulting in more body roll.
No real racecar uses progressive rate springs. Rising rate geometry, maybe, but the springs will be linear. The extra variable causes unpredictability as the suspension moves through its range of motion. Fine for a street car though.
With only 240hp, S2000 owners needn't worry about any "massive front-rear weight transfers"...
[QUOTE]Originally posted by BBSpoon
[B]Rear toe in the S.
Here's my theory. I have not taken a bump-steer gauge to the S, but I am assuming that the rear suspension toes-out as it compresses. If that assumption is acceptable then, you should look at toe in relation to body roll. In a turn one side compresses and the other side droops. Another way of looking at it, one side toe-out and other toes-in. More body roll, more toe changes. What do you have? Essentially the rear wheels steering out of the turn, passive 4-wheel steering. Sounds really nice but introduce a mid-corner bump or an abrupt mid-corner correction and you're toast. This is called roll-steer. Its usually a big NO-NO.
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