Can anyone technically minded tell me exactly what is involved in the bumpsteer mod, ie a step by step guide. What is needed, what needs to be done etc.
Thanks.

I could do! having seen it done on mine on monday but not really in my interest to do so as it is a mod Powerstation have worked hard on in developing. It's their bread and butter so to speak.
doubt you will find anyone willing to tell you this.
Pay your money and have it done......;)

Andy

It's not really a secret how you do this to a car. There are many books covering vehicle suspension systems and their geometry. It's basically a case of making the steering rods and suspension arms run as parallel as possible. This can be acheived by moving one, the other, or both of the aforementioned components in relation to eachother. The real trick lies in getting hold of the necessary equipment to find what needs moving and by how much. Powerstation use their alignment kit to do this.

Is it not worth adding 3mm shims to the rack and taking it out for a spin to see how it feels?

Er, no, that is just a daft suggestion ;)

Mo,

That might work, with a bit of experimentation on shim size, but you would still need to go and have the geometry re-setup on an alignment rig somewhere as its likely to affect the toe in the process of moving the rack. There are (at least) several outfits around the country who can do a half decent job of the alignment setup, so there is probably one relatively near you. :) (IIRC, you were londonish based, so Elite might be worth a call).

Moray

Also note: mine needed more than 3mm.

Richard

OK maybe I should of said more but you get the general idea. Richards required more but most of the people I've spoken with have required 3mm shims so that's a good place to start.

If you live to far from PS and have someone with the right equipment close by (ie Elite) then why not give it a go.

It's not rocket science;)

I measured a friends shims - 3mm so I started there with my own car - perfect :) It's so much easier with coilovers as you can just let the car down on the platforms and jack it up whilst checking the toe change :)

What is the shim how do you make it - 3mm?
sorry I'm not english so don't know what it is but I'm very far from PS and would like to try myself

No body want to explain some more.
Do PS put some hardwear to do the bumpsteer mod or do they only tune the existing

You guys must be mad! youre gonna start messing with your cars suspension without any idea about what needs doing and hope it helps? On a performance car that you use hard? wow, really...?

I had my car done at PS just over a week ago and Nick spent a long time pouring over settings to be sure what he was doing was right. my car needed more than 3mm and he applied a lot of clever tricks to get to the figure needed, then fitted and checked what he'd done. Total professional that man.

No one car will be like another due to manufacturing tollerances. This mod is worth the money alone to hear Nick explain bump steer and how this mod alleviates it.

Stop being stingy and have your car set up properly.

Jon.

My car is set up correctly and no doubt Andys is too. Did Andy make the trip from the Highlands to Cheltenham??

I said 3mm was a good place to start - IF you know what you are doing and IF you have access to a good 4 wheel alignment centre.

I'm not being stingey I'm just stating my opinion from my own experience and from speaking with many others.

Just as Mo said, you can do this yourself if you know what you're doing.
Strange how people think that everyone outside a BIG garage is thick :D :D

Shim - translation - Spacer or strip of metal in this case which is 3mm thick (vary's from car to car)This is fitted behind the steering rack to lower it by the required amount to eliminate the designed in bump steer.

Could someone enlighten me more as I want to do the mod here in Greece.

Elias

Ok, Take your point that you can do this if you know what youre doing and have access to 4 wheel alignment kit, but lets face it if you do then you already probbaly know what to do as you will know the theory of bumpsteer etc. Comment about Big garages was beyond me, sorry, I put far more trust in independants than dealers these days - they dont scratch my car or let the teaboy out for spins at lunchtime (dealers reading this - you know who you are!)

What I'm worried about is people shimming their racks on their driveways cos they saw a thread on here saying that by sticking a 3mm shim under the rack they will instantly get better handling. The reality is that 3mm may be too much or not enough, depending on your car and as such you could make it a lot worse rather than better with a blanket 3mm apporach.

I drive my car how it was intended and even though Im mechanically very knowledgeable (worked on and built many cars / bikes over the years) and i'm still glad I forked out to have this mod done professionally as I know my car is right and i now know what effects were desired and whats been gained by doing it - I also understand bumpsteer now. If I had another car I would still pay to have it done properly even tho I know what to do now.

Jon.
PS. By all means whack some shims in and give it a go, be sure you torque everything back up right before taking to the road. Let me know how it goes and exactly how much you needed and why etc.

If I was not so far from PS I would go strait but it's very far so expensive and I should take at least 3 day's of wich is even harder.
That's why I like the idea of trying with 3mm and GO TEST
Fabien

this mod is probably the best value mod you can do to your scoob £130

what is the point of even thinking of doing it yourself or experimenting with it

X-Scooby do you have problem reading?
Some people are leaving gealy far from PS and to the 130 I should add an other 500 for the pravel + 2days not working 400 so it come
to 1030 pounds and that is quite expensive for this even if it's I'm shure the best mod

Fabien, in 2000 I went from Paris to Power Station and got the Bump steering allignment together with Anti lift kit. Yes it took 3 days and it was a nice trip. Cheltenham where PS is located is a nice city. Best money ever spend and it was a nice 3 days vacation.

Do the trip you will never regret it
Lars

Forgive my lack of knowledge, but would somebody mind explaining exactly what "Bump Steer" is please ?

Bump-steer describes a suspension geometry where the toe angle of the front wheels changes when the springs are compressed. Literally, the front wheels steer outwards (causing understeer) when the suspension is in bump (cornering hard or braking - not driving over bumps).

The mod changes the geometry so that compressing the front suspension doesn't cause the front wheels to toe outwards. This makes the car turn in more sharply and behave more predictably, although some a few people feel it makes the car more nervous. As with all handling adjustments, you may need to adjust your driving style to get the best out of the mod.

My bump steer mod has just destroyed one of my steering rack mounting rubbers. The two washers and shim will be removed ASAP and I will be getting the geometry re-aligned again without the bumpsteer mod.

The car is slightly lower than normal due to having LEDA suspension so I'm still unsure why I opted to have the bump steer mod in the first place.

Am I the only one ?

What are the symptoms? And what size washer did you have fitted - is the washer rubbing against the rubber?

Thanks
Richard....who's trying to trace a new knock from front nearside (UK Offside) somewhere....bumpsteer done 8-10 weeks ago :)

I didn't see the size of the washers as my mechanic was under the car at the time. I think it was the washers that caused the damage to the rubber.

Sounded like a creaking noise when the steering wheel was turned as the rack was loose.