Bumpsteer mod
 

Has anyone got any before and after photos or photos of what they do???

Hello anyone out there :Suspiciou

They shim the steering rack to eliminate the changes in (castor ??? ) wheel steering angle when the wheel to chassis distance changes, like going over a sudden bump, i.e. bumpsteer and then reset the alignment.

No piccies, sorry

It isn't really something you can photograph, the shims are only a few millimetres at the rack end of things. No external signs.

Main benefit is that understeer is reduced because the geometry in a turn doesn't change for the worse when the outside wheel is compressed and the inside wheel is uncompressed. I had it done on my MY98 a few years ago and the effect is particularly impressive.

So how do they know how much to shim it??

They put the car on an alignment ramp, strap lasers to the wheels and measure the change in toe as the car moves from full bump to droop (they jack the car up then hang 2 technicians from the car). The actual change is minimised by sticking a piece of metal under the steering rack (it goes between the rack and the body) to adjust the height of the rack.

They have done so many they can roughly guess straight away how big the shim needs to be

HTH

Are powerstation the only guys that do this or can it be done somewhere nearer to myself? (Aberdeen)

Thanks lads for the info, I'll still like to see some pics though :)

bum steer mod? pmsl, the most expensive bit of garabage know.

whole point is they remove some of the pressure on the sterring rack and alow it to move slightly, normally done with a pair of 4mm washers!!!!

my question is this, y the hell would you want to remove some of the feel of the steering?

o and by the way if you uprate evrything else, anti roll bars, drop links, anti lift kit etc it has same effect (although admitedly more expensive) and makes car handle better not just slightly feel better.

Hopefully someone from powerstation will reply :)

just out of interest how much is said mod?

I don't know

hope it aint much more than £20. still don't think its worth it even for that

i did mine myself for free ;)

lol, no comment mickey!!!! pmsl

you don't quite have a grasp on what It does TBH :lol:

my understanding is this


your rack is not the same height as your wheels

therefore when you hit a bump your toe in/toe out changes which affects handling, standard car is set for numptys ;)

adjustment of bumpsteer can help change the handling while the suspension moves up and down

i've been told, cos i asked the very question, the extra washers remove the presure on the steering rack alowing it to move if impacted aka bumped.

dont think anything to do with the handeling is left standard on mine :):):):):):):) lol

:confused:


who told you this answer?


the washers are only part of the "mod" the rack still needs shimmed down by the same amount as the washers, other wise your just driving around with a slack steering rack???????

thats why i thought that it would be loose dude, mate of mine took it off the car he bought and had whiteline stuff all round added instead.

so your mate bought a car and he gave you the expert info on what the bumpsteer mod was?

yeah kinda, heard it from a couple of other people as well though, when they were explain about what they'd had done. so dunno mate, can only go on what i've been told it is and what does

Note: Not had it done.

Ummm who did you ask and was it Impreza specific?

My understanding is that it is an adjustment of the steering rack height to minimise understeer on bump or particularly, cornering. I haven't got it done but if it does what it says on Powerstation's tin, it means slightly less arm twirling to take corners and less adjustment to get the car through. Also means if you lose the back end there may be less arm un-twirling and re-twirling required to recover the situation.

J.

So StickyMicky, would you like to post how you did yours with some pics then ;)

:D

im not taking mine apart to take pics :eek:


my explanation above tells you what to do anyway??


i cant remember how much i shimmed mine now, i done it about 2 years ago

It should really be done as part of the alignment, then they can check if it is working properly, whilst swinging like apes from the front of the car. Powerstation is the place to go.

Why, we've got wheel alignment equipment at work :)

LOL at this thread. I think Tidgy's mate needs to go learn something.
He took out the washers :lol: hope he took out the shims too then (cos you can't see them)
It doesn't loosen the rack allowing it to move :lol: PMSL
Standard cars are set up to understeer for Mr average and therfore for safety in the event of the driver running out of talent.
Bumpsteer removes this tendancy so the front wheels actually point where you want to go instead of pointing towards the hedge. :D

You can't just shove washers in it has to be measured on an alignment rig and if you don't know what you're looking for then you are pissing in the wind.

Yes it re-positions the rack to a lower position so that the track rod arms follow the travel of the lower suspension arms, that way when the suspension is compressed or extended the toe part of the alignment stays the same throughout it's travel.
nothing to do with castor vulnax ;)

And no I aint showing you how to do it. :p
Oh yea and price is around £70 quid for the alignment and another £70 for the bumpsteer.
You can have an alignment without the bumpsteer
but you cant have the bumpsteer without an alignment. :D


Andy

It's okay Andy, I've now got enough info to have a play at the weekend :thumb:

:D

mwaaahhhaaaaaa

that means i was correct :D

i measured mine with some lazer equipment :D :D