?????Please explain BUMPSTEER?????
22 October 2001, 01:42 PM
#3
Scooby Regular
Join Date: Aug 2000
Location: Where age and treachery reins over youthful exuberance
Posts: 5,275
Likes: 0
Received 0 Likes
on
0 Posts
Ian, I coudln't get the link to work.
Scoby, bump-steer is a feature of most cars (apparently). When the front suspension compresses under braking or cornering, bump-steer induces toe-out which promotes understeer, which is a safety feature (easier to control than over-steer). Trouble is, it makes turn-in and steering response worse and bump-steer removal involves adjustment of the front suspension so that compression results in no change to toe, ie wheels stay parallel.
Most say the difference is a transformation, others say it made things a bit better, but I've never heard anyone say bump-steer removal made their car worse. The general conclusion here is that Imprezas leave the factory with generous tolerances in their geometry so obviously some cars will benefit more.
Bump-steer removal is nothing like the Prodrive geometry settings which also improve turn-in, and are easily done by your local dealer. The down side here is that camber is changed which, if you do a lot of motorway driving produces uneven tyre wear accross the tread.
PowerStation have the kit to set up your suspension accurately, and it's nothing like the equipment found at your local tyre fitters. Someone told me it costs £30k. They charge £100 plus VAT (I think) to do the bump-steer trick and set all four up true. It takes about an hour and a half, as I recall, and you then get a printout which tells you what your settings are to within a thousanth of a knat's whisker. Nice guys, too. Well worth it.
Richard.
Scoby, bump-steer is a feature of most cars (apparently). When the front suspension compresses under braking or cornering, bump-steer induces toe-out which promotes understeer, which is a safety feature (easier to control than over-steer). Trouble is, it makes turn-in and steering response worse and bump-steer removal involves adjustment of the front suspension so that compression results in no change to toe, ie wheels stay parallel.
Most say the difference is a transformation, others say it made things a bit better, but I've never heard anyone say bump-steer removal made their car worse. The general conclusion here is that Imprezas leave the factory with generous tolerances in their geometry so obviously some cars will benefit more.
Bump-steer removal is nothing like the Prodrive geometry settings which also improve turn-in, and are easily done by your local dealer. The down side here is that camber is changed which, if you do a lot of motorway driving produces uneven tyre wear accross the tread.
PowerStation have the kit to set up your suspension accurately, and it's nothing like the equipment found at your local tyre fitters. Someone told me it costs £30k. They charge £100 plus VAT (I think) to do the bump-steer trick and set all four up true. It takes about an hour and a half, as I recall, and you then get a printout which tells you what your settings are to within a thousanth of a knat's whisker. Nice guys, too. Well worth it.
Richard.
23 October 2001, 08:10 AM
#5
Scooby Regular
Join Date: Sep 2000
Location: London
Posts: 7,039
Likes: 0
Received 0 Likes
on
0 Posts
Here you go:
http://www.drivingtechniques.co.uk/S...nu=63&PageID=5
Also, if you do a search there are a lot of good threads where this has been discussed.
Matt
http://www.drivingtechniques.co.uk/S...nu=63&PageID=5
Also, if you do a search there are a lot of good threads where this has been discussed.
Matt
Thread
Thread Starter
Forum
Replies
Last Post
ReallyReallyGoodMeat
Non Scooby Related
12
21 September 2015 11:34 AM
alcazar
Non Scooby Related
5
18 September 2015 11:49 PM