Spoke to Alan at Falkland a few times. Initially he spoke with Powerstation and came back to me to say yes they could get the antilift kits, but I explained again that it was bumpsteer removal I wanted. He was going to speak to Powerstation again about it. He seemed unconvinced of the benefits or need for it, so please all pester him to sort it out. I told him there were a load of Scottish Scoobies wanting it done - mine included!

 

I have sent this to Kevin Adam at Falkland Performance: KAdam54@aol.com is Falkland's email address.

Kevin,

Powerstation do this (and are the only ones that do it), and I was discussing with Alan about him finding out about you being able to do it at Falkland. It involves shimming the steering rack and improves straight line steering feel, reduces understeer and reduces squirming under braking. It is highly rated almost univerally by all those that have it, and has been for over a year. Powerstation charge about £100 for it which is mainly 2 hours labour as it is quite fussy to do as well as geometry.

Are you able to offer this service? Geometry is good, but this is apparently a lot better.

John Banks

Details below of an old Scoobynet thread on the issue, which echoes many view on it.

Finally summoned up the courage to get the Powerstation bump-steer mod fitted to my UK car. I wish I had spent the £100 when I first bought the car!!
The adjustment is made by loosening the steering rack and placing accurately measured shims in to counteract the bump/rebound geometry change.

I watched them do this on my car the the result was a perfect, with no change in bump or rebound.

IMHO - my car was already set up well on a 4 wheel laser set up - I would attribute the mod to the bump steer adjustment

What is it:
Bumpsteer happens when the front suspension is being compressed (bump) and the standard steering/suspension geometry causes the wheel(s) being compressed to toe (steer ) outwards. This causes understeer when cornering and may cause "wandering" under braking. Powerstation modify the steering geometry so that compressing the suspension does not affect the angle of steering at either wheel.

What happened:
Arrived at Powerstation mid morning after a pleasant run up the M40 & A40 from Oxford. Put the car on the rollers and handed over to Nick to do his stuff. £100 buys you more than just the bump-steer mod, they take the time (several hours) to check & recheck the camber & toe settings on the car.

First, they "true-up" all four wheels, getting them to point where they are supposed to when the car is at rest. The equipment they have can measure all the way down to individual minutes - that's 1/60th of a degree! Just try drawing two lines with a protractor that close together! The equipment is so sensitive that Nick likes to close the garage doors because gusts of wind will affect the readings!! This took a little time because Nick is a perfectionist and likes to get things just right.

Once the basic alignment was set, Nick then measured the change in toe that happened when the front suspension was compressed. The readout then tells him how far to drop the steering rack. In my case, it required a 3mm shim. Now this might sound a little worrying, but it isn't. As far as I could see, the steering rack is not under any great vertical tension (unclip it and you can waggle it around with your hand!), so nothing is being bent or twisted by inserting a 3mm plate between it and the mounting point. They also shim the holding clip so that isn't under tension either - a lot of thought has gone into this mod!! Once the rack was tightened up, Nick then rechecked all the toe & alignment settings to make sure they were still where they should be.

And then he sent me out on a test drive to see what I thought!! No money has changed hands at this point, yet they're quite happy for me to see what I think. First impressions? I'll save them for later, what was more impressive was that I felt that the steering wheel was very slightly offset clockwise when I brought it back. No arguments, no silly "road camber" arguments, Nick just put the car back on the rack and readjusted everything until he was certain it was straight. Another drive around the block was enough to convince me that this time, everything was bang-on.

The difference:
Wow! Wow-wow-wowow! Forget what anyone else has said, you can feel the difference at any speed. The car is more planted on the road. It drives in a straight line. When you turn the wheel, the car reacts almosts instantly. More significantly, you need less steering lock for a given turn. For the first couple of days, I found that I was applying a little too much lock all the time. Now that there isn't any bump steer, you don't have to correct for it, so I'm left just steering for the bend and not the bumpsteer.

There is more grip. Now this isn't some silly "feeling", I've measured it. I could take a local roundabout pushing at 50mph, the car is now neutral at 55mph and will probably go on to 60 before drifting. When cornering, I can feel the sides of the seats pushing into my ribs even more than before.

Is it safe? I think so. The car doesn't wander under braking, it just stops in a straight line. Lift-off oversteer is only a consideration if you drive on the limits of adhesion, simple "brisk" driving isn't enough to provoke the car.

Don't waste time on buying new suspension components until you can get the best out of the old ones. I've always felt that the standard UK suspension is very good (unlike the brakes! ) and this mod has confirmed what I thought. The car now turns into corners with real vigour and wants to follow your every input.

What more can I say? Better handling and more grip for less than the cost of two tyres!

For the technically minded:
Before:
Rear camber -1°25'/-1°13'
Front camber -0°33'/-0°34'

Rear toe +0°07'/+0°15'
Front toe +0°05'/-0°01'

Thrust +0°04'

After:
Rear camber -1°25'/-1°13'
Front camber -1°24'/-1°22'

Rear toe +0°01'/+0°02'
Front toe +0°04'/+0°04'

Thrust +0°00'

 

hi there

couple of things that i thought i would mention here. on my scooby, i have had the geometry done by falkland, then i had the bump steer mod done. the car had loads of suspension bits done one but at the time. here is the progression

geometry->geometry + eibach springs-> geometry+ ALK--> bump steer--> up rated anti roll bars.

as some of you know i have done many track days etc, so i think i can judge how my car changed with the various mods.

IMHO the thing that actually made most of the difference is the ALK and the eibach. the bump steer mod was ok but no amazing as people actually describe it, it never really transformed the car as people described it either. i think if you geometry is correct you will find it hard to notice a big difference. Psychology plays probably a big part here. However if your geometry is way out as most people that go to PS have to start with you will get a huge improvement.

Maybe I am cynical or something. . I am not that usually easily impressed by something because someone said so. Again cars could be different.

The other thing I am sure Kevin will be very impressed by you telling him what bump steer is

 

"Kevin will be very impressed by you telling him what bump steer is"

I am sure he won't be impressed, but when I asked Alan about getting it done he came back to me and offered me an antilift kit, so I thought I would put it in black and white what I meant. I have been asking them for ages to do this and I always get offered plain old geometry which I already had from them. Kevin has done the same when I asked for bumpsteer removal. I want to try bumpsteer as most people do describe a marked improvement even with existing well set geometry. I am also not planning an antilift kit or springs for various reasons. If they knew all about it perhaps they would already be doing it? AFAIK they haven't tried it, and Alan said they would need details from Powerstation. So I don't think there is any harm in being quite clear what I want. I am the customer after all and have no duty to impress dealers/retailers by telling them exactly what I want!

It seems everyone's opinion of what mods make a difference is different. I have heard yes and no for induction kits, porting headers, PPP, backboxes, springs, bumpsteer, brake lines, brake support brackets, broquets, even aftermarket ECUs amongst many others. Some say they make a massive difference others say snake oil.

 

i have spoken to falkland ages ago about the bump steer and explained to them few times but i don't think they were too keen on doing it. why do you think i drove all the way to power station??. they have done it before to rally/race cars so they kind of know what it is. but you will find for the first few cars they will do time/money will be an issue. unless they do it on few different cars they won't really know how long it should take.

think of it this way john. i have had my evo7 3months and i have changed the geo about 4 times until i got the one i like. and before that i used to get the geo checked on my scoob every 3-4 months. now, go and find me someone that has taken that much care to set up his car and then see if they have done the bump steer and take their opinion ??.

t-uk for example does not even use laser equipment to set up his geometry but still drove more at the limit than any other subaru around knockhill. so it is more in the way you drive than anything, else while the bump steer is a good it is not that good. it will make the car understeer a little less.

and before you rule out other mods, how about giving PS a phone and asking them how good is the ALK ?.


i know you spoke to a lot of people that said one thing or another but i have tried almost most of the mods that are available to the scoob at somepoint or another. does that make me an expert ? i don't think so. but at least i can give you an opinion based on my personal experience.

as for the other mods you have mentioned if they were done correctly they all should work period. butwhat you have to bear in mind that every car is different and respond differently to different things. but you already knew that.

just my very honest opinion but i wouldn't give any less.

[Edited by Sam Elassar - 3/25/2002 2:06:13 PM]

 

Trouble is Sam whilst your opinion is highly valued there are other equally knowledgable/obsessional types who do rate the bumpsteer very highly indeed. I can see what you mean though about getting it right if Falkland for example have not done is extensively with road going Scoobies.

I'm not so sure there is a "right" answer regarding these mods, but bumpsteer is something I would like done if it can be made available locally. It will probably the only other thing I do to the car's handling.

 

I think mods can be very susceptive to your own driving style and even preconceptions to some degree.

I've just had Eibachs fitted and the geometry checked (not PD settings) and I don't feel the my understeer probs have been reduced (which I hoped for). IMHO the Eibachs do make a big difference to the cars handling, especially to the rear of the car when cornering and there's more control under braking.

I'd certainly be interested in getting the PD geometry done at Falkland and if poss the Bumpsteer and/or ALK too. The latter would depend on other people experiences.

If 8 of 10 cats prefer Bumpsteer, then I'd be prone to go with the majority and check it out for myself

Stefan

 

Kevin at Falkland has asked George to look into it for us.

 

John B why do you only want the Bump steer? why dont you want the eibachs or another spring set up?
i found the standard springs way to wallowy to even think of ridding understeer? just curious thats all?

ive said before when Falkland set my car up i told them didnt want any under steer, as even TSL said you can have it understeer/neutral/oversteer.
i have the eibachs, geometry and 215/40/17 F1's and my car doesent understeer given you dont try and enter a 2nd gar hairpin in 4th doing cruising at 60 if you know what i mean.
it just digs in, yes if you try and palant the power before the apex it may try and push on slightly but thats bad driving rather than being smooth.
ive dne 40000 miles in this car from new and 95 percent of them have been on A/B roads so i know the car well.

i couldnt imagine how much more positive it could be with the bumpsteer? but i havent tried one yet so until i do...

as for laser alingment alot or most race cars are set up with gauges whilst all four wheels are on the ground, well thats ow my mate always has there 993/968 race car set up.

Lee

 

For the sort of bumpy roads I like driving on I think it is firm enough, and it already gets knocked off line too much by mid corner bumps. Certainly for a daily driver the ride quality is quite firm enough, just as the (deliberately quiet) decat system is loud enough. I am not plagued by understeer the way I drive, but less squirminess under braking and more steering feel and less sogginess about the straight ahead would be nice. The limit of the car is way beyond what I use in cornering except powering out of bends in the wet. I am also on Toyos on 16s. I am not convinced 17s would benefit me either in the wet/snow which is the only time I would want more grip.

There is also the issue that my insurance goes up by £200 just by fitting Eibachs and another £100 for 17s. Find another insurer maybe, but it is £1200 a year already with my engine mods all declared.

So bumpsteer is a quick, easy, cheap improvement in feel I hope?

By running negative camber are we not all just (badly) compensating for the bumpsteer rather than sorting out the problem?

[Edited by john banks - 3/25/2002 9:57:52 PM]

 

Maybe we john, but i find witth Eibachs around cumbria which is fairly bumpy the suspension seems to be more composed with eibachs i.e more stable, it seems to follow the road contours much more composed fashion rather than stepping off line, IMHO.

The 17's i had first were 215/45/17 which felt sharper than the 205/50/16 which has slightly more sidewall to roll around on, when i went to 215/40/17 F1 goodyears the steering feels sharper again an the turn in is more positive, i tend to run lower pressures which suits my driving as 33 psi up front in the wet just feels awfull and very slippy IMHO, i tend to run 30psi all round, and with even a short blat up the road the pressure increases 2-3psi immediately.

when i was on 16 i used to run 29 all round and thst certnly gav me me confident feel and the pzeros were happier at that than he higher pressures some run, but its IMHO and horses for coures.

why dont you try running a little less pressure in your 16's john and see...start at 28 all round then try 29 all round but check when cold.

Lee

 

I'll try running a few different pressures - run 33 F 30 R cold at present. This pressure on the Toyos feels much softer than the same on the RE010s, and a lot quieter too.

 

Lee,

My car's had Eibach fitted and (like you) I'm also running Goodyear F1 215/40/17's, but I still get more understeer than I'd like

Did the geometry make a big difference or did you get it done same time as the Eibachs or tyres?

Stefan

 

Lee,

what model year car do you have?,I have never felt that eibachs would offer much of a benefit to MY99/00 cars.

out of all the scoobs I have chased round K/hill,by far the most impressive was a car with coilovers+slicks.Sam,you will remember it from last year,the gold and green one running standard boost of 15psi,until we noticed the boost guage was in bar .

 

hi john
i totally agree with you, full suspension is the way to go. saying that these guys are looking at very small changes and the eibach has improved teh handling for sure. it has got the same spring rating as the standad car but lowers the car a little bit improving the centre of gravity.

actually i am getting eibachs for my evo7.

sam

 

So does that give you more chance of hitting the bump stops on big bumps if the spring is the same rate but shorter - ie less suspension travel?

 

never hit a bump stop with them or with out them. the car felt slightly firmer, but only very slightly.

anyone that came with me in the car thought the car was a lot more composed than standard.

sam

 

T-uk hello there,
My car is a MY00 and IMHO i think it has helped the handleing of the car, i did 30000 on standard and ive now done another 10000 with the eibachs, like sam says it feels more composed over the twisties, thers are certain roads i travel all the time so i could tell the difference straight away, not mind blowing but it does firm it a little, with the 215/40/17 i wouldnt want it any firmer on the roads round here as my 22 month little girl travels in it and i wouldnt want to rattle her teeth out

Ozzy i had the 17 inch O.Z fitted at 20000k, then the Eibachs and geometry at 30000 it had p-zeros then and it did understeer in the wet still, but fitted F1's and had the geometry re set and the car feels great, as i said in the wet anything higher than 29-30psi in my tyres it feels less surefooted IMHO.

I checked the pressures this am with the gauge when cold and theres 28 all round, it feels firm enough and i have to be doing something silly to make it understeer so much that it worries me.

all iMHO thats all i can say. everybody will find something different that suits them, if it was more of a trackday only tool i would probably go for coil overs, but as my car is 17 month old and ive done 40000k in it i couldnt possibley have somthing to firm or uncomfortable.

Lee

 

blah blah

[Edited by EwanS - 4/8/2002 11:24:21 AM]

 

"essentially the rack and arms are at an angle to the road (we all agree on that) well if you make the angle shallower...mechanically the forces are more balanced - increasing responsiveness and reducing the spreading of the wheels by directing the forces directly into the chassis"

So applying that logic, lowering the car by 1mm will have the same effect I think not.

"If on the other hand you just shim the original mounts, then, although the feeling is improved due to the increased angle between rack and arm, the forces that are acting on the rack and arms/joints are unbalanced because the rack is being moved up and out from the plane that you are looking to get it into, and will result in reduced rack life. "

Sorry, but this is just plain wrong, moving the rack by means of shims or modified mounts will have exactly the same effect.

 

who needs eibachs ,any lower would probably bottom me out

 

Ah, but lower = stiffer = less body roll = more grip = faster laps times = .......Probably less fun in your case

 

If they are the same rate then maybe they're no good for your 'extreme' usage

Lower + uprated will reduce body roll which will keep the tyres at a better angle to the road, increasing grip. The reduced weight transfer due to the lower C of G will also increase grip as the cornering force is distributed more evenly between inner and outer wheels.

I actually cut chunks out of my Cossie's chassis for the drive shafts, to let it sit lower

The downside is, the more grip, the more sudden the breakaway, this may not be what you are after as you would need to use less oversteer for the fastest times.

But then if you want to still catch Sam ........

 

Ewan, your logic is flawed, it has nothing to do with the angle of the arms to the road. Basically there is a steering movememt as the suspension changes due to compresion or extension. The 'Shim' alters the position of the rack and negates this steering. It has more to do with the position and angle of the track rods relative to the track control arms.

 

Has this died a death or what? Is it still going on?

 

Falkland are awaiting some shims and then they are going to get me in as a guinea pig. I'll update you as and when.

 

Woohoo!! Still needing mine done.

 

Any updates?

Scoty

 

Falkland still waiting for the shims to arrive. I'll give them a ring again.

 

Falkland now have the shims from today, I am booked in next Thursday as the guinea pig.