luke2152
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| posted on 18/12/16 at 02:19 PM |
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Measuring bump steer
Does anyone have any practical ideas for measuring/reducing bump steer in a diy manner. I'm thinking in terms of jacking the car up, removing
my front springs/dampers and measuring toe in at standard ride height, then lowering it on the jack and measuring again. Using straight edges or
string to project a line forward along each front wheel etc. And then moving the steering rack about to try and eliminate it. Not done anything like
that before so I'm not sure if there is a simpler/better way.
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gremlin1234
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| posted on 18/12/16 at 02:48 PM |
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project binky covered this is quite a lot of detail recently
edit to add:
it was episode 11, a year ago
http://www.badobsessionmotorsport.co.uk/project-binky-episode-11/
quote:
In episode 11 of Project Binky, we grapple with bumpsteer and Ackermann angles, we wrestle with the gear-shift mechanism, sort out the
passenger seat and fit the handbrake. And we drink tea of course.
edit 2:
se also part 10
http://www.badobsessionmotorsport.co.uk/project-binky-episode-10
quote:
In episode 10 of Project Binky, we mainly concentrate on getting the controls sorted. There’s pedal box and steering action along with a fight with
some major bump steer.
[Edited on 18/12/16 by gremlin1234]
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SJ
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| posted on 18/12/16 at 02:51 PM |
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I did mine DIY and it was quite easy. As you probably know what you are trying to achieve is a setting where the wheels don't
'steer' left or right when the suspension goes up and down.
I parked the car about 2 feet from a wall, jacked up and put the chassis on blocks at roughly normal ride height and removed the spring & damper.
I then fixed a cheap laser pointer onto the brake disk and drew a vertical line on the wall. By lifting the suspension I could see how much the laser
pointer deviated from the line.
It was then a matter of putting washers under the rack mounts until I minimised the deviation from the vertical line as much as poss on both sides, be
repeating one each side until I was happy.
It took a bit of time but was worth the effort as it transformed the car.
You could do it quicker with 2 laser pointers and some board fixed vertically each side of the car.
Stu
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mark chandler
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| posted on 18/12/16 at 03:30 PM |
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Remove shock and wheel, lock the steering wheel straight ahead, tie a lazer to the disc and point at a board then lift and drop the axle through full
movement and watch the lazer dot move left to right, use trig to work out how bad.
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froggy
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| posted on 19/12/16 at 02:08 PM |
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A little more work and you could have an easier to read set up .
My supertracker has flags which sit on the centre line of the rear wheels with marks every 10mm
Front gauge marks are every 5mm with the laser 400mm from the centre line of the front wheel .
Two lasers pointing at each other at the front and the other two facing backwards you can set the toe equally as the rear flags will read the same
when each side is equal and no need to work anything out with some marks on the front to show toe change
[IMG]http://i144.photobucket.com/albums/r187/froggy_0[IMG]
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