mark chandler
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| posted on 9/5/07 at 05:35 PM |
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Handling query
Fiddling about with the suspension on my car at the weekend, hopefully getting it right.
Set ride height, corner weights and other bits and bobs and have managed to dial out oversteer, understeer etc so feeling quite pleased. Small amount
of toe in and negative camber on the rear, same on the front.
So my problem now is I can no-longer get the back out. It tries to slide, then grips and the front washes out at the edge, when it was on
'build' settings if oversteered, handling is now much better.
Until the limit the car is very neutral, feels just right.
The rear end is soft, it feels like the LSD cuts in and then straightens the car, If I get harder springs on the rear what will this do ?
Cheers Mark
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flak monkey
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| posted on 9/5/07 at 05:43 PM |
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Harder springs at the rear will increase the tendancy to oversteer. Harder springs at front will increase tendancy to understeer.
David
PS theres other ways of changing the characteristics, but I think that answers your initial question 
[Edited on 9/5/07 by flak monkey]
Sera
http://www.motosera.com
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britishtrident
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| posted on 9/5/07 at 06:39 PM |
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yep Soften the front or harden the rear
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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russbost
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| posted on 9/5/07 at 06:56 PM |
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Assuming you have adjustable shox you should be able to "dial in" a bit of oversteer by just reducing damping on the front by a notch or 2
&/or increasing damping on the rear
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britishtrident
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| posted on 9/5/07 at 07:02 PM |
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Altering the damping won't change the steady state handling only the transient handling characteristicts.
Steady state handling balance is down to roll couple distribution (spring rates, anti-rol bar, roll centre heights) or tyre characteristics and
contact patch area.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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britishtrident
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| posted on 9/5/07 at 07:05 PM |
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Thinking about it ---- it might be an idea to check the bump steer. It could be the toe-in is increasing as the weight transfers when you feed in
the power.
[Edited on 9/5/07 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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mark chandler
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| posted on 9/5/07 at 10:54 PM |
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Hi there,
Thanks for the responces, its not bump steer at fault, I spent a lot of time eliminating this at the chassis build stage. The back just seems very
grippy, like a fixed axle go-cart infact.
By backing off weight transfers to the front and it tucks in, its just very hard to get the rear to kick out.
I,m thinking all the weight is moving towards the rear because it is soft so harder springs will slow this down.
I suppose the winning question is how hard, at present it has 170lb springs with a ratio of 4/5 so effective strength is near 145lb.
Cranking up the damper makes a harsher ride and the end snaps a little sooner but as the car settles down the front starts to wash out. Not so much
understeer as initially it turns in, more the front losing grip.
I,m thinking 220lb springs and maybe an anti roll bar up front to keep the balance.
Regards Mark
[Edited on 9/5/07 by mark chandler]
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