Bumpsteer !!!!!!!!!!!!!!!!!!!????????????????
23 December 2002, 05:33 PM
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Hi there, is there somebody that can explain me what bumpsteer is, I already have an ALift Kit and Swaybar Connectors from Whiteline, a very good geometry setup but I read a lot about bumpsteer and Here In Belgium there no one who knows...
23 December 2002, 10:51 PM
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Find a bend (constant radius to make it easy) with a bump/lump in the middle.
Drive round said bend at a reasonable speed.
Note how you have to correct the steering wheel slightly as you go over the bump in the middle of the corner..........
Drive round said bend at a reasonable speed.
Note how you have to correct the steering wheel slightly as you go over the bump in the middle of the corner..........
24 December 2002, 08:27 AM
#3
Hmmmmmmmmmmm....... i always thought that bump steer had something to do with the front wheels splaying (spelling?) out when the suspension was loaded up causing lots of nice understeer.
So what do you call it when i hit a dead cat in the middle of this 'constant radius' bend..... is that the infamous catsteer
. Sorry just taking the **** 
.I would be interested to know how you could get rid of your bumpsteer tho..... even after having powerstation's bumpsteer mod done when the car hits a bump the bloody steering wheel still moves. I must take it back and get it done properly .
Tony.
So what do you call it when i hit a dead cat in the middle of this 'constant radius' bend..... is that the infamous catsteer
. Sorry just taking the **** .I would be interested to know how you could get rid of your bumpsteer tho..... even after having powerstation's bumpsteer mod done when the car hits a bump the bloody steering wheel still moves. I must take it back and get it done properly .Tony.
24 December 2002, 09:59 AM
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So what do you call it when i hit a dead cat in the middle of this 'constant radius' bend..... is that the infamous catsteer
I got carrierbagsteer the other day
26 December 2002, 04:50 PM
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Correctly, Bumpsteer occurs when, due to sudden compression of the suspension, there is a rapid transition from a toe-in to to toe-out (or vice versa) this is too rapid for comfort and can lead to a 'jittery' moment.
If you are unfortunate you may take the car to the Bumpstops, this is the jounce point when in motion and the car can behave very unpredictably.
This may help prevent your problem.
This is my Problem and Cure sheet.
Understeer on entry to a bend - Increase the 'rebound rate' of rear shocks. Decrease the 'bump rate' of front shocks. Increase the rear brake bias or just brake earlier!
Oversteer on entry to a bend - Decrease the 'rebound rate' of rear shocks. Increase the 'bump rate' of front shocks. Decrease the rear brake bias, or brake later!
Mid-bend Understeer (constant 'wash-out') - Stiffen rear spring and/or anti-roll bar. Soften the front springs and/or anti-roll bar.
Mid-bend Oversteer (constant 'tightening' without driver input) - Stiffen front spring and/or anti-roll bar. Soften the rear springs and/or anti-roll bar.
Exit Understeer - Increase rebound of front shocks. Decrease bump of rear shocks. Stiffen rear springs/anti-roll bar. Soften front springs/anti-roll bar.
Exit Oversteer - Decrease rebound of front shocks. Increase bump of rear shocks. Soften rear springs/anti-roll bar. Stiffen front springs/anti-roll bar.
Car is slow to respond to driver's input - Stiffen the car by (in this order) springs then anti-rollbars then shocks. Increase tyre pressure check heat spread.
Car hops over the bump - reverse of the above.
If you are unfortunate you may take the car to the Bumpstops, this is the jounce point when in motion and the car can behave very unpredictably.
This may help prevent your problem.
This is my Problem and Cure sheet.
Understeer on entry to a bend - Increase the 'rebound rate' of rear shocks. Decrease the 'bump rate' of front shocks. Increase the rear brake bias or just brake earlier!
Oversteer on entry to a bend - Decrease the 'rebound rate' of rear shocks. Increase the 'bump rate' of front shocks. Decrease the rear brake bias, or brake later!
Mid-bend Understeer (constant 'wash-out') - Stiffen rear spring and/or anti-roll bar. Soften the front springs and/or anti-roll bar.
Mid-bend Oversteer (constant 'tightening' without driver input) - Stiffen front spring and/or anti-roll bar. Soften the rear springs and/or anti-roll bar.
Exit Understeer - Increase rebound of front shocks. Decrease bump of rear shocks. Stiffen rear springs/anti-roll bar. Soften front springs/anti-roll bar.
Exit Oversteer - Decrease rebound of front shocks. Increase bump of rear shocks. Soften rear springs/anti-roll bar. Stiffen front springs/anti-roll bar.
Car is slow to respond to driver's input - Stiffen the car by (in this order) springs then anti-rollbars then shocks. Increase tyre pressure check heat spread.
Car hops over the bump - reverse of the above.
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