bump steer
Scooby Regular
Joined: Jun 1999
Posts: 1,496
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Perhaps you wouldn't mind asking them a question or two (and posting the replies!) that have been bugging me...
I'm led to believe that the amount of shimming under the steering rack is specific to each car, which is why you can't do this mod at home. Anecdotal evidence suggests that its between 3mm and 25mm.
So why is it so different? Assuming a proper 4-wheel alignment has been done first(and so everything is exactly in the place designed by Subaru), why is the geometry so different from car to car that in one case you can use a thick washer and in another you need a whacking great spacer?
Secondly, if you only need a thick washer why does such a small difference in the position of the steering rack 'transform the handling', as has often been reported
..or is it that the people that need the one inch spacer are the ones that say the handling is transformed and the ones with the thick washer are those that say they couldn't really tell the difference?
Finally, braking in an improved straight line is often quoted. Is this a direct result of the bumpsteer mod, or is this just due to the anazingly accurate 4 wheel alignment that Powerstation can allegedly do?
Or does anyone else know the answers prior to the link's visit?
I'm led to believe that the amount of shimming under the steering rack is specific to each car, which is why you can't do this mod at home. Anecdotal evidence suggests that its between 3mm and 25mm.
So why is it so different? Assuming a proper 4-wheel alignment has been done first(and so everything is exactly in the place designed by Subaru), why is the geometry so different from car to car that in one case you can use a thick washer and in another you need a whacking great spacer?
Secondly, if you only need a thick washer why does such a small difference in the position of the steering rack 'transform the handling', as has often been reported
..or is it that the people that need the one inch spacer are the ones that say the handling is transformed and the ones with the thick washer are those that say they couldn't really tell the difference?
Finally, braking in an improved straight line is often quoted. Is this a direct result of the bumpsteer mod, or is this just due to the anazingly accurate 4 wheel alignment that Powerstation can allegedly do?
Or does anyone else know the answers prior to the link's visit?
Scooby Regular
Joined: Sep 2000
Posts: 7,039
Likes: 0
From: London
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by MartinM:
<B>...Secondly, if you only need a thick washer why does such a small difference in the position of the steering rack 'transform the handling', as has often been reported...[/quote]
Because you only need to make very small changes to make a vast difference when it comes to geometry.
For more details answers and info, do a search in Suspension as there is loads and loads of good info waiting for you...
Matt
<B>...Secondly, if you only need a thick washer why does such a small difference in the position of the steering rack 'transform the handling', as has often been reported...[/quote]
Because you only need to make very small changes to make a vast difference when it comes to geometry.
For more details answers and info, do a search in Suspension as there is loads and loads of good info waiting for you...
Matt
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