zoton

Okay part two

You'll recall the setup was..

UK Turbo
Whiteline ARB mid setting
Eibachs
Standard dampers 45000
Geo set up

After some excellant advice on here...
I added OZ 7x17 with 215/40s.

After a week I would say the effect was pretty impressive. The steering feel is better..? due to less sidewall deflection. Oddly another nice benefit is less 'rebound' over speedy bumps. I am wondering if this is an indication of better control over uneven roads at higher speeds? I guess its more complicated than that.

On Monday it is a front strut brace.

One question before the next step....thinking logically doesn't an Anti Lift Kit gonna promote Dive? And isn't that bad? Excuse the ignorance I know its all front and rear balance but I want to take the right step.

thanks

Mark

Andy.F

Hi Mark

The anti lift kit does not reduce lift during acceleration, in fact it increases it ! there was a thread on here some time ago which whiteline were involved in, it ended with them doing some further testing and agreeing that their anti lift kit actually promoted lift !
That said, the overall effect on the handling is positive for other reasons.

Andy

Andy.F

Here is the Whiteline story -
__________________________________________________ ___________________
Whiteline Automotive
Scooby Newbie


Join Date: Jul 1999
Posts: 18
#43

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G'day everyone,

Following is a copy of an answer posted on MRT Forums in response to the original question directed to us by Andy F.

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Andy, at this point we don't really have a lot to add apart from what we've discussed already on "Scoobynet", but....

We agree that the changes to geometry as argued by yourself and others is logical and can lead to the conclusion proposed but there are other factors involved. I want to buy some time to do something we've been meaning to do for a while. That is, setup some controlled tests to obtain some quantative data.

We have a heap of anecdotal and circuit test results that show that fitment of the ALK will lead to lower lap times and higher corner exit speeds in general but I accept that this is with out using scientific controls. We accept that the dynamic caster increase is significant (frankly thats why we did it) and that this may be the reason for the performance gains but this does not deal with a couple of other issues.

It doesnt explain a reduction in standing acceleration times with the ALK fitted, nor does it explain the positive improvement in pitch dynamics resulting in less corner exit understeer when simply spacing the factory mount further away from the body. Frankly, this is one of the first things we did to test the theory during initial development many years ago and 3 drivers in a blind test confirmed our assumptions. Its not something you want to do on the road for obvious reasons but I stand behind the outcome as I was initially quite sceptical that we could tell the difference.

Anyway, no more speculation, we're off to do some testing so we can identify exactly whats happening so we can report in detail. This won't happen overnight but it is underway.

Thanks for your patience.

Regards

Jim Gurieff

Whiteline

Andy.F

And the outcome ----

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21 November 2002, 06:22
Whiteline Automotive
Scooby Newbie


Join Date: Jul 1999
Posts: 18
#53

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G’day everyone,

It’s been quite a few weeks since we last spoke but we’ve been quite busy. We’ve finally finished the “trade-show” season and all staff are back at work so I thought it was time to report back on the ALK testing. This was conducted partially while I was away from the office so we’ve only just finished compiling the data.

I have to admit that the basic conclusion is a little embarrassing when compared with the existing text of the product description. Specifically, our testing data found that the fitment of the ALK increases from lift under power while reducing understeer and delivering the positives described by customers and quantified thru extensive track testing. How to answer this apparent contradiction?

The basic design for the ALK was done over 5 years ago with the help of a consultant. During the initial research stage we referred to the concept as an “anti-lift kit” meaning that it dealt with the geometry of “anti-lift”. The concept delivered the dynamic results we wanted with reduced lap times and understeer however the name stuck through. A great deal of time and further research has since been invested yet the description has remained unchanged. Our apologies for any confusion we have caused in the meantime but we very much appreciate the opportunity to revisit the issue and learn from this debate. Here are the key excerpts from the report we prepared;
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Effect of Whiteline Automotive ALK

The ALK effectively modifies the position of the side view instant center on the front suspension. The side view instant center is the pivot point for the side view swing arm (also the pivot point for the suspension at that instant), which is a line drawn from the tire contact patch to the side view instant center. The slope or angle of this swing arm (effectively the position of the instant center) describes the amount of anti-dive and anti-lift present in the front suspension.

The instant center is found by the intersection of the two lines. The first is the projection of the lower control arm, say through the chassis mounts, behind the front wheel the second is the normal to the axis joining the tire contact patch to the top of the strut tower, from the top of the strut tower.
(Note: To be absolutely correct these lines should be projected onto the wheel center plane, so any lateral angles in the lower control arm will effect the instant center position. However the lower control arm in the WRX is relatively flat which will give minimal effect)

Together with the position of the instant center, the WRX’s wheelbase, CG height above the ground, % front torque (for anti-lift) and % front braking (for anti-dive) are required to calculate the anti features of the front suspension.

With the ALK fitted, the rear mount of the front lower control arm is lower by about 20mm. There is also a castor change by moving the mount outwards (however this has not been taken into account). This has the effect of lowering the instant center and decreasing the angle or slope of the swing arm resulting in the following anti-dive and anti-lift coefficients, expressed as percentages.

As can be seen in the above calculation spreadsheet (can supply separately as can not embed into message), with the ALK fitted the anti-lift and anti-dive coefficients reduce to 0%.

The effect of lowering the % anti-lift / anti-dive

If the suspension has 100% anti-dive / anti-lift, then all the longitudinal load transfer experienced when braking and accelerating is carried through the control arm, leaving the springs unloaded and no deflection present. If there is 0% then the springs take the entire load, giving full spring deflection.

By lowering the % the front suspension becomes “softer” under acceleration or braking. This gives rise to the higher diving and lifting that has been experimentally shown. (These results are also in a table

A softer front suspension during acceleration and braking will even out the load on the front tires, giving a higher total cornering load available or more front grip. This will lead to less understeer when cornering under power or brakes.

Softer front rate will also allow better wheel tracking over rough roads, keeping the wheels in contact with the ground. In simple terms, fitment of the ALK has the effect of delivering a softer effective spring rate during the pitch moment.

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From this you can see that the product name is misleading and inappropriate. This will be changed and qualified even though it deals with the geometric concept of “anti-lift”. However we can happily report that the improvements claimed for the product are still valid and quantifiable.

I look forward to continuing this discussion once everyone has had a chance to digest the above.

Best regards
Jim Gurieff

Whiteline Automotive

Andy.F

Full thread here http://bbs.scoobynet.co.uk/showthrea...2&page=1&pp=30

drb5

iTrader: (4)

so, what does it all mean, basil?!





can we eliminate anti-lift without the hardest coilovers money can buy then?

Andy.F

Basically it means, yea it works, fit it and don't get hung up on the name

Do you want to eliminate anti-lift or eliminate lift ?

Andy

drb5

iTrader: (4)

pmsl!

now your just trying to confuse me!

911

Me too. I fitted the ALK to try to kill acute understeer. It did a bit towards the war but not much IMHO.
Fitting the MRT top mounts and leaving the ALK on (I'm too lazy) really had a pronounced effect along with some radical geometry on all corners.

Understeer can be induced by driving hard and being a prat (lift off in a hard bend), but most times its great now.

With a great chassis, soon time for the Andy F turbo,Apexi,headers etc etc etc etc.

911

zoton

Thanks Andy

Nice and clear and a lesson in the value of a bit of research

I get to like Whiteline more and more.

Mark

beemer02

Hey Zoton?
Suffer from a bit of indigestion do you? Or has the Scoob given you an ulcer?

DuncanG

Has anyone actually measured the height of the control-arm pick-up points on their Impreza?

When I checked the geometry of my gen2 legacy which I assumed had the same geometry as the GC8 imp I found that the height of the rear pick-up with the ALK is 8mm lower than the front. This means that the ALK has created pro-dive and pro-lift geometry and not just neutralised the antis.

StickyMicky

when i fitted the ALK to my car, it chnaged the way it was driven a lot
it felt really strange to be honest

you get to know your car and such and it was like driving sumbody elses
front end lift seams to be reduced, although ive noticed that in a stright line it still felt like the car was rocking backwards, i had put this down to squat at the rear?

in cornering, i still havnet fully adapted to the way it handles now, but where i would expect massive under steer, i find i can now wind on more lock and use a lot more throttle and simply power around the corner

it really is a strange bit of kit, but i would recomend it, especialy if your standerd bushes are worn (mine had 70K+ on them and were due for swapping anyway)

my current spec is as follows

Gmax lowering springs
New Excel G KYB shocks
uk turbo top mounts
rear camber bolts
ALK
powerflex front ARB bushes
Cusco front and rear upper braces
Cusco lower rear brace

my next mod will be a rear ARB although im not sure which make to go for yet and i would rather get used to what i have 100% then keep changing it and ending up confused

Andy.F

Duncan - Correct Did you not read the link
http://bbs.scoobynet.co.uk/showthrea...2&page=1&pp=30

DuncanG

Thanks Andy I remeber that thread well - I think I was about the only one that agreed with you. I know that the ALK drops the rear mount point but I expected it then to be level with the front (or thereabouts) to nullify the antis to create a neutral geometry - thats what Whiteline are saying anyway.

The point I was making is that on mine it goes past that point and actually creates pro-dive and pro-lift geometry. I'm not saying thats necessarily a bad thing btw. I'd be interested to hear if anyone has checked the heights on their imps so I could see if this is a leggy/imp difference.

Your prob on your way by now but good luck at TOTB

JIM THEO

I didn't find any remarkable difference with the ALK on both MY00 and WRX03, bigger and better overall modification for me was the Suretrac rear differential (for WRX R160 housing) along with adjustable rear anti roll bar and better geometry.
JIM

911

Jim, i didn't 'feel' any difference with the ALK either; this is why I went and fitted the MRT top mounts to dial-in much more caster.
911