DavidRB

Finally summoned up the courage to get the

david

Is this mod suitable for any suspension?

I have Leda B, would I feel the above improvements if I had the bumpsteer sorted?

Dave

SecretAgentMan

1. Yes

2. Maybe not as much as with the stock susp. The Leda B kit (if supplied through Scoobysport) has quite stiff springs, so the body won't roll as much - hence reduced bumpsteer already there.

I'm deffo getting it done when I get over, even though I've got the said kit from Pete.



/Jerry - Sweden

PeterPerfect

I also needed to wind off steering inputs for the first few days
Still enjoying the direct steering..even at low speeds
ALK also fitted....tighter when cornering under power.

Big Bear

I liked the fact that the car now handles more like a rwd car than a fwd car , ie *** out action
Definately worth getting done , still smiling after a year without bumpsteer .

MRK

DavidB


THANKYOU for that message. I always thought that bumpsteer was something different. But the way you describe it, and the improvements made I will definitely get this mod done asap.

I was at Dono on Sunday and my biggest problem was the front end drifting wide, even though I've had the geometry adjusted.

Powerstation hear we come.


Mark

mutant_matt

Powerstation are boys no doubt!!!!

I just couldn't believe what a huge difference the changes would make. Best £100 ever spent

This is worth doing on <B>ANY</B> Scooby as they are all effected by the Bump Steer Mod.

Matt.

Neil Reay

Great Information DavidRB.

Is there any downside after having the bumpsteer mod, i.e excessive tyre wear or excessive wear of any other components.

Neil.

Jaz

Got mine boked in for Tuesday, cannot believe the difference you feel it makes

paul w

David,

Well explained mate,i understand it now.

Big bear,

Still smiling after a year without it

Big Bear

Paul
Yes still smiling coz the bumpsteer is gone
But who would smile after a year without it ?????

Luke

I was lucky !! took my Uk turbo estate to Power Station and was told after they set the Alignment up that it would not need to have "bump steer " done . Drive back was great .£60.00 WELL SPENT

If you look at all the cheap mods topics "ECOTEC" etc. The P/S bump steer mod must be number 1 on your list

DavidRB

Glad you all liked the post, I'll beat that felstead fellow yet!

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by david:
<B>Is this mod suitable for any suspension?[/quote]
Don't see why not, but I would ask the guys at Powerstation for their opinion, it's their mod, they know the details.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by Neil Reay:
<B>Is there any downside after having the bumpsteer mod, i.e excessive tyre wear or excessive wear of any other components.
[/quote]
Don't think so. As you can see, my car has always had 1°25' of negative camber on the rears, yet despite numerous motorway journeys, they were worn evenly when I replaced them.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by Jaz:
<B>Got mine boked in for Tuesday, cannot believe the difference you feel it makes[/quote]
I can believe it!

Gussie Cup

...and another big thumbs up for the Bumpsteer Mod!

Noticed a big difference to the 'weight' of the steering. It feels heavier, more solid and with the Ant-Lift kit (also fitted at Powerstation) it all feels so much more planted on the road.

I would recommend this mod without reservation.

Alan McCaskie

Is this the same mod as having the Prodrive geometry settings done on your standard suspension by your dealer? And are there any downsides , i.e. increased wear on the suspension components?

Cheers

Alan

IWatkins

Alan,

No, the Prodrive setup is different, it basically just trys to dial out some of the understeer through geomery changes. Bump steer isn't changed.

Powerstation setup does the geometry setup as well, just that they also 'dial-out' the bump steer.

I'm told (I don't own a Scoob) that the two different setups are chalk and cheese.

I've also yet to hear of anybody who has found a downside and this mod has been done for well over a year.

Cheers

Ian

DavidRB

The "Prodrive settings" are just changes to the static camber & toe settings. Nothing is done to the steering rack, so the bump-steer remains.

I suspect that Prodrive are fully aware of the benefits of removing bump-steer, but are unable to do anything about it because of their contract with Subaru.

Subarussian

DavidRB (and other bump steer enthusiasts),

Do you know how far out your geometry was to begin with? Are you sure the difference in steering is due to the BS mod, and not because you've sorted out the geometry? Just asking

I've experience the same "wow" factor just from sorting out my geometry (which was way off when I got the car from my dealer) and setting it to the Prodrive spec. Same feeling of improved traction, turn-in and "too much lock".

However when I drove a car with the BS done I thought the steering felt very light / remote, and the car felt wobbly and unstable.

I guess my point is that in order to get a fair assessment of the BS mod you should've first driven your car with just the geometry sorted, and THEN with the BS done.

Anyway, enjoy the improved handling, whatever created it



[This message has been edited by Subarussian (edited 25 February 2001).]

DocJock

Andrei

I went through Std Subaru - Prodrive settings - PowerStation settings/bumpsteer removal in the space of 4 months.

The bigger difference was the second change by some way.

Thanks again to the PS boys

DJ

DavidRB

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by Subarussian:
<B>Do you know how far out your geometry was to begin with?[/quote]Check the end of my original post.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by Subarussian:
<B>Are you sure the difference in steering is due to the BS mod, and not because you've sorted out the geometry?[/quote]Not 100%, but I'm pretty certain! Changing the static camber & toe would improve things, but every time you pressed into a corner, the bump-steer would appear and I reckon I'd notice.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by Subarussian:
<B>However when I drove a car with the BS done I thought the steering felt very light / remote, and the car felt wobbly and unstable.[/quote]Two thoughts:
1. When I was there, Nick said that they offer a more "aggressive" setting, better suited to people who do track days, I was only after the road-going setup. Do you know what settings the owner had asked for?
2. Every change in a car's suspension requires a change in driving style. If you carry on grabbing large handfuls of lock and backing off in every corner, then you won't get the best of the bumpsteer mod.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by Subarussian:
<B>I guess my point is that in order to get a fair assessment of the BS mod you should've first driven your car with just the geometry sorted, and THEN with the BS done.[/quote]Good idea, although you're talking about nearly a day's work now if you add the time to take the car out inbetween the geometry & bumpsteer changes.

In the end, what suits one person won't always suit everybody. But I (and so many others) think that this mod really does transform the car.

GP

could someone enlighten me as to whether any BS corrected cars are also lowered in any way, if not, do lowered scoobs have a proportionally larger movement of the steering rack to compensate or no ?

Gary Foster

GP - If the car has stiffer suspension (I assume this is what you mean by lowered) there will be less body roll (less compression / extension of the suspension) so bump steer will not show up as much. It will still be there though.

All - I had standard / Prodrive / Bumpsteer all done in the same month (as I bought the car) as I thought the car handled so badly in the first place

Prodrive settings make only a small difference under heavy cornering and make it feel very wooly at any other time. BS mod makes it feel like a completely different car (though you might not like it) - can confirm that you can go round corners faster, you can therefore lose it (esp back) easier as well.

No understeer on track any more (yeeha !)

GP

true enough - but I'm really referring to the fact significant lowering can actually alter the directions in which toe occurs under suspension compression - I don't know scoobs, but a -40mm lowering on my car can make the steering arms go past the horizontal and initially, cause a -toe, then, pushing harder, a +toe - I'm after some opinions and experiences from you guys as the car I am setting up has responded (decriptively speaking) almost word for word in the same way as a scoob does, it seems (read very well - I too almost rode up the kerbs on apexes before I learned the new feel) - though I achieved my geometry correction of the steering arms using a different method, as the rack could not be moved, what I did though was compensate in the exact opposite dimensions to the amount of lowering I'd previously carried out.

Reading up on this mod for scoobs, I'm assuming the 3mm or so shim is valid for standard ride height - I'd intrigued whether this changes for a lower riding scoob..

anyone ?

IWatkins

GP (and all),

There seems to be a misconception of the modification. Just shimming the rack will not remove bump steer. The way a car handles depends on the settings/locations etc. of *all* the suspension parts. Even standard cars of the same year are different when you get down to setting up geometry.

Just putting in a 3mm shim will *not* fix the bump steer.

You actually have to measure the bump steer to make any sense of the situation, i.e. in which component(s) of the system is it occuring, before you even think about moving the rack or other parts.

The shim size is calculated from the measured bump steer. Some cars don't need shimming at all, others need a very large movement indeed (25mm) of the rack, or even other parts moving.

What is important is that the BS mod. really does make a difference if done correctly. If it is done incorrectly you will probably get a much worse handling car.

Whether it is to everyones taste, well thats another matter.....

Cheers

Ian

Gary Foster

GP

I won't pretend to understand exactly what you are talking about (too technical for me)

However

The shim may or may not be 3mm as each car is different, I believe it is a trial and error thing (ie shim, compress suspension and see of the toe goes out, add bigger shim etc), Tolerances in manufacture etc

In addition, I would *guess* it is not possible to remove bump steer completely as the influence that the mounting point for the steering makes would be different at different ride heights, the aim being to get minimal bump steer when you compress the suspension from standard.

At the end of the day this is just a question of physics, there's no black magic involved, but to fix it requires sensitive alignment gear and a knowing what to adjust in order to have the required effect.

Why not phone Powerstation and see if they'd be willing to set the car up for you ? If you lower the car you'll have to get the tracking done anyway so £100 for a track + bump steer mod is a bargain whatever you drive.

Gary

[edit Oops, Ian posted at the same time as me, doh ! read Ian's reply he knows what he's talking about]

[This message has been edited by Gary Foster (edited 26 February 2001).]

GP

aye I know all the suspension theory behind this, and the fact that unless you have some pretty darn tricky suspension setup, zero BS is just not possible - it's all about getting the best effect for the range of suspension movement encountered during driving - I would contend though that 95% of the theory behind the mod is very simple - it's all to do with the shallower arc decribed by the steering arms v the suspension wishbone(s) - in my case a simple macpherson strut setup doesn't require rocket science to figure it out - not knowing the scoobies front suspension setup, which I assume at the very least is a double wishbone, I'm simply just curious to expand my knowledge a bit as I'm currently trying to tune my suspension for track-orientated action - It was after all the talk of this here on your forums that initially sowed the seed for modding my own car, which has worked wonders, I might add.... in the immortal paraphrase of the comic book guy.. "best mod.....Ever" - and I should know I've done few

Ian I can understand your desire to explain the wider implications.. but is it at least fair to say a 'rule of thumb' would be lower = larger BS correction ? In my case this is definitely yes (see above about the simple suspension setup)

Gary Foster

GP

Scoobies have Macphersen struts up front as well mate, none of this adjustable every which way multi-link stuff here

Gary

GP

well bugger me sideways there's hope for my shed yet then - the front half anyway.. there's a beam at the back

Gary Foster

Oh Christ ! it's not an Astra is it !!

Scared the life out of me when I looked under the rear end of mine ... Ah so thats why it doesn't go round corners then (slaps head)

Plus some idiot had chopped the roof of it (My Old Astra GTE Convertible)

Gary

GP

hehe..lol - it most certainly is

a teensy bit non standard tho , it's even stopped trying to kill me (I should think so after ten years!)

c'mon there must be some suspension tekkies reading this ?