thoughts on anti-lift kit
19 September 2002, 12:59 AM
#34
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Andy.
Now I'm sure that you didn't mean to imply that I know the ALK doesn't work but won't admit it publically, especially I know that it does (as opposed to the theoretical models being used in the above posts). 
Andy, I never held myself out to be a self acclaimed expert?
Pavlo, the main effort of the ALK is to reduce power on understeer, not something normally encountered in the straight line scenario you described?
Suspension geometry is far more complex than just B.Eng (Hons) can cover, the basics maybe but this is more than that. I don't hold even a B.Eng (Hons)so I'm not best qualified to correct your theories.
I'll mail Jim at Whiteline to try and cast some light onto it further. Simply though ALK does work it will retain weight under power over the front wheels hence improving traction at the front under hard acceleration. (Regardless of any theoretical models).
Laws of physics can't be altered, but cherry picking the parts that you know and constructing a theory around them doesn't mean you have a valid argument.
Mike.
[Edited by Mike Tuckwood - 9/19/2002 1:07:21 AM]
OK I'll try again, although I don't really expect the supplier to admit in public that an anti lift kit....doesn't
Andy, I never held myself out to be a self acclaimed expert?
Pavlo, the main effort of the ALK is to reduce power on understeer, not something normally encountered in the straight line scenario you described?
Suspension geometry is far more complex than just B.Eng (Hons) can cover, the basics maybe but this is more than that. I don't hold even a B.Eng (Hons)so I'm not best qualified to correct your theories.
I'll mail Jim at Whiteline to try and cast some light onto it further. Simply though ALK does work it will retain weight under power over the front wheels hence improving traction at the front under hard acceleration. (Regardless of any theoretical models).
Laws of physics can't be altered, but cherry picking the parts that you know and constructing a theory around them doesn't mean you have a valid argument.
Mike.
[Edited by Mike Tuckwood - 9/19/2002 1:07:21 AM]
19 September 2002, 01:45 AM
#35
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Just in case this sheds a little more light on the general principles, this is a direct extract from Whiteline site.
***********************************
ALK's (anti-lift kits) explained?
Most current performance vehicles are based on the same floor pan as their more pedestrian cousins. For example the WRX is largely based on the original 1989 Liberty, the EVO Lancer on the CC platform of 1994. The original platforms were not designed for performance, but rather for reliability, potential ground clearance, passive safety, the "Wally factor" and above all else, ease of manufacture.
The basic front configuration is maintained with struts and a Y shaped lower arm which reflected the industries change to unrestricted crumple zones for better energy absorption in frontal collisions. This is further enhanced for ease of assembly while the basic geometry was set for the lowest common denominator driver and environment.
The lower arm is typically located at the front by a pressed metal cross-member and by the floor pan at the rear. The last branch of the Y locates the bottom of the strut allowing the wheel to be controlled in a fore-aft direction while the arm pivots at the front and rear locating point, allowing vertical wheel travel through bump.
The original geometry of this arm and its subsequent operation meant that the designers had provided anti-dive, better off-road "clamberability" and a lower centre of gravity at the front. Just as importantly however, there was an issue of packaging, how to fit a larger engine lower with out also having to modify the floor pan and rear pickup point. All this while trying to deliver a safer package.
Anti-dive is very important for car designers as it addresses what we call the "Wally factor". That is, the panic or knee-jerk response of a very average driver to a tricky situation mid corner. Anti-dive geometry slows down the weight shift to the front wheels which results in a gentle tightening of the cornering line with throttle lift-off, the standard panic reaction. However, one of the costs for this design compromise is front lift under acceleration as anti-dive will generally mean pro-lift. Gross acceleration and resulting front lift was hardly a major compromise for the base model vehicles but then along came the RS Turbo Liberty followed by the WRX or the GSR in the case of the Lancer.
These cars were/are performance bargains because the manufacturer changed what it considered as important/cheap, but left other items that they felt would not greatly detract from the overall performance. The WRX really tested the original design because of its enormous acceleration. As any early WRX owner will confirm, powering out of corners means nose up and loads of understeer as the weight shifts to the rear and the front tyres scrub for traction. Power launches will see the nose lift while 70% of the available torque tries to find a release through the front wheels. Because tyre grip is directly related to load, a reduction in weight or load over a tyre will result in a reduction in available grip. Couple a lateral cornering grip requirement with a tractive forward grip demand and we have a compromise for both aspects, reduce the load and there is only one possible outcome, understeer.
The anti-lift kits change the location and geometry of the control arm pick-up point to remove the "lift" resulting from the original geometry. This does not however make it pro-dive, so brake dive does not increase dramatically. It simply brings the geometry back to a more neutral position away from its pro-lift bias. We acknowledge that this change must result in a certain amount of increased dive under brakes, but most drivers would accept that it's easily offset with a slight mod to driving style. Those people likely to experience corner entry understeer may feel an increase but this in itself maybe a symptom of too higher speed at corner entry and initial turn-in.
In most cases the new mounts also relocate the arm in another plane to add static positive castor. They are also likely to feature a performance polyurethane bush which replaces the original high compliance rubber type. This serves to maintain a closer link between static and dynamic alignment settings through reduced compliance and distortion under load. The additional static positive castor coupled with the low compliance bush means more positive dynamic castor.
If you don't know the benefits of positive castor, see the Alignment FAQ here
To put all this into perspective, you have to also understand that every car is designed to a compromise. For example the WRX was originally based on a very pedestrian floor pan allowing Subaru to bolt on a heap of go faster bits while still selling a high performance solution for under $40,000. How much would it have cost if they had to design and manufacture unique new mounts for the WRX rather than waiting for the inevitable changes to filter through the new models in due course?
These products do not offer magical solutions but are based on sound engineering principles used for race car preparation and vehicle design. They rely on an understanding of basic vehicle geometry and its effects on handling and dynamics. Some people are disappointed with the outcome, or feel that they have actually gone backwards in a handling sense. Our testing proves that it can cut 0.75 seconds or more off your lap times but we accept that everyone is different and different drivers look for different characteristics. However, it is not possible to argue that it does not make a difference, to do so would be to argue against basic physics.
Here's what Michael South,
current NSW WRX Club champion had to say (2001 Class 3)
"….. I have been sceptical on the Whiteline Anti Lift Kit, I felt that it wouldn't help my car as it was set up reasonably well and would only work on soft spring rates ,yet I wanted to test this for my self to see if it would or would not work , + the new under body strut brace also bought out by Whiteline , after others saying good things I felt it was something that I needed to test on the track for myself as turn in is always going to be a good thing on a rex .
Still behind in my class I needed to go faster, so I Remove my hard bush and fitted the Anti Lift kit, a very quick alignment and out I went, after 4 laps it was hard to feel much of a change, but the stop watch showed around 4 tenths faster, there were some corners that you could tell it was less push on power out of a corner, .It allowed me to hit the power just a slight bit earlier, I then did a true alignment with my string line and I'm sure had I been allowed out for another run I would have found a bit more.
It works so slight it is almost not something you can feel, but the stop watch shows it does work. You might be saying I was driving it harder and that was the time found, anyone who was there would have seen that I was driving 110% on the limit all day as second or third wasn't an option.
So it does work, I still think now some more changes to my ride height, bump and rebound will find more from it."
In fact, go to Whiteline Automotive and read throough the FAQ's sections as they are all inextricably linked to each other.
Mike.
19 September 2002, 09:54 AM
#36
I'm not arguing that it improves the handling of the car Mike, as I have heard more good reports than bad.
As for this not being covered in the average B.Eng degree, you're probably right. But I know from personal experience it's covered in a B.Eng in Automotive engineering at Loughborough University.
My only quarm is with the name, and what it's claimed to do by many people that talk and write about it. I believe it can reduce lap times, and improve the feel of the car, and increase grip in and out of corners.
But, what I still don't beleive it does, is reduce front lift in a straight line, which the Whiteline blurb clearly claims it will ("On power launches...").
As I have said before, if you want to reduce lift, then use anti-squat, which is done at the rear, or put harder springs at the front, or all round.
Paul
As for this not being covered in the average B.Eng degree, you're probably right. But I know from personal experience it's covered in a B.Eng in Automotive engineering at Loughborough University.
My only quarm is with the name, and what it's claimed to do by many people that talk and write about it. I believe it can reduce lap times, and improve the feel of the car, and increase grip in and out of corners.
But, what I still don't beleive it does, is reduce front lift in a straight line, which the Whiteline blurb clearly claims it will ("On power launches...").
As I have said before, if you want to reduce lift, then use anti-squat, which is done at the rear, or put harder springs at the front, or all round.
Paul
19 September 2002, 10:37 AM
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Mike
My reference was to Whiteline as the supplier, I was talking about my post on the MRT forum "whiteline helpline" !!
Just how wrong can they get it !!!! The one part of the suspension they change creates increased dive under braking, this they thankfully acknowledge 
If that braking force is 'reversed' ie acceleration force, it will provide the opposite reaction LIFT.......It's not rocket science FFS !
PS Not saying it doesn't improve the handling, just that it does NOT do what it says on the tin.
My reference was to Whiteline as the supplier, I was talking about my post on the MRT forum "whiteline helpline" !!
Anti-dive is very important for car designers as it addresses what we call the "Wally factor". That is, the panic or knee-jerk response of a very average driver to a tricky situation mid corner. Anti-dive geometry slows down the weight shift to the front wheels which results in a gentle tightening of the cornering line with throttle lift-off, the standard panic reaction. However, one of the costs for this design compromise is front lift under acceleration as anti-dive will generally mean pro-lift.
The anti-lift kits change the location and geometry of the control arm pick-up point to remove the "lift" resulting from the original geometry. This does not however make it pro-dive, so brake dive does not increase dramatically. It simply brings the geometry back to a more neutral position away from its pro-lift bias. We acknowledge that this change must result in a certain amount of increased dive under brakes
If that braking force is 'reversed' ie acceleration force, it will provide the opposite reaction LIFT.......It's not rocket science FFS !PS Not saying it doesn't improve the handling, just that it does NOT do what it says on the tin.
19 September 2002, 04:52 PM
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Ah, Ok I see what you mean. <Mike runs around collecting his teddies>
That to me is just written badly...... I'll have a stab at what I interpret they were trying to say.
When they are talking about dive, they mean that the geometry already there, allows for a slow dive rate to be present and to engineer that in they must have also introduced some amount of lift element in the reverse plane (acceleration).
Hence meaning that as OEM, the necessarily present anti dive element also means there is some pro lift element.
What they are saying then (I think) is that they have taken some anti dive out by using poly bushes that don't deflect as much under load and that the geometry changes, (although relatively small in the big scheme of things) they do reduce the amount of lift under power out of corners?
Mike.
That to me is just written badly...... I'll have a stab at what I interpret they were trying to say.
When they are talking about dive, they mean that the geometry already there, allows for a slow dive rate to be present and to engineer that in they must have also introduced some amount of lift element in the reverse plane (acceleration).
Hence meaning that as OEM, the necessarily present anti dive element also means there is some pro lift element.
What they are saying then (I think) is that they have taken some anti dive out by using poly bushes that don't deflect as much under load and that the geometry changes, (although relatively small in the big scheme of things) they do reduce the amount of lift under power out of corners?
Mike.
20 September 2002, 12:16 AM
#39
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Mike
I'm not sure that I follow that fully. When you reverse the force from brake to accelerate, anti dive becomes anti lift so decrease one and you also decrease the other, it's the same link (the one they move down) that determines both
I've posted my question on the MRT website, the Whiteline advice forum but after 2 days there is still no reply.
Did you get anything back in reply to your Email ?
Andy
I'm not sure that I follow that fully. When you reverse the force from brake to accelerate, anti dive becomes anti lift so decrease one and you also decrease the other, it's the same link (the one they move down) that determines both
I've posted my question on the MRT website, the Whiteline advice forum but after 2 days there is still no reply.
Did you get anything back in reply to your Email ?
Andy
20 September 2002, 02:19 AM
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G'day everyone,
Pardon the intrusion but we were told by Mike that there was a bit of discussion going on re our "snake-oil" anti-lift kit and its main performance claims :-).
"Andy. F", we received a copy of your original post to MRT Forums mirroring this discussion argument at, quote "Posted - 18 Sep 2002 : 21:21:18" (EST Australia). We will be technically 2 days late in replying at 9pm tonite (currently 11am.) Our policy is to answer all email within 24 hours of receipt so we should have answered this by 21.21 last night but our server is being upgraded so we are a little behind overall. It sounds as if you'd almost like to see us maintain a silence for whatever reasons but a reply is currently being put together. (Who is "Claudius" anyway?)
Apart from that, we dont like to rush these sorts of answers as there is a lot of stuff to wade through to make sure we actually answer the question. Secondly, its one of those questions that forces one to look at the whole issue afresh, check your assumptions and confirm that it all still hangs together. We'll be back soon.
In the meantime, I'll poor some more fuel (or maybe sand) on the fire with this;
- The anti-lift kits primary design function was to reduce front lift under power by reducing the AMOUNT of anti-dive. It moves the geometry closer to neutral.
- Though the above was the primary design goal, we also added +0.5 static caster as a sweetener. The design, size and material used in the repacement bush helps us then acheive up to +1.0 deg increase in dynamic caster.
- Fitment of the ALK DOES NOT lower the rear pickup point to the horizontal (relative to the front) or beyond. Dot green would deliver pro-dive, dot blue is neutral but the ALK locates this point around 2-3mm ABOVE the blue or around 19mm below original.
- To argue against the geometry changes resulting from the relocation of the rear pickup point as claimed by Whiteline is to argue against front anti-dive geometry as designed by OE chassis engineers for almost every contemporary chassis. Again, we just reduce the amount of anti-dive which is inherently pro-lift.
- The claim that reducing front lift by increasing rear anti-squat is symptomatic of "band-aid" suspension cures and leads to sacrificial tuning. That is, losing something at one point to benefit another. The front and rear of 99% of vehicles are "decoupled" and must be treated seperately if possible. A front lift problem should be dealt with at the front, increasing rear spring rate or changing anti-squat geometry does not fix the front lift problem. It just "dulls' it.
We'll be back soon.
All the best.
Jim Gurieff
Whiteline Automotive
[Edited by Whiteline Automotive - 9/20/2002 2:23:56 AM]
Pardon the intrusion but we were told by Mike that there was a bit of discussion going on re our "snake-oil" anti-lift kit and its main performance claims :-).
"Andy. F", we received a copy of your original post to MRT Forums mirroring this discussion argument at, quote "Posted - 18 Sep 2002 : 21:21:18" (EST Australia). We will be technically 2 days late in replying at 9pm tonite (currently 11am.) Our policy is to answer all email within 24 hours of receipt so we should have answered this by 21.21 last night but our server is being upgraded so we are a little behind overall. It sounds as if you'd almost like to see us maintain a silence for whatever reasons but a reply is currently being put together. (Who is "Claudius" anyway?)
Apart from that, we dont like to rush these sorts of answers as there is a lot of stuff to wade through to make sure we actually answer the question. Secondly, its one of those questions that forces one to look at the whole issue afresh, check your assumptions and confirm that it all still hangs together. We'll be back soon.
In the meantime, I'll poor some more fuel (or maybe sand) on the fire with this;
- The anti-lift kits primary design function was to reduce front lift under power by reducing the AMOUNT of anti-dive. It moves the geometry closer to neutral.
- Though the above was the primary design goal, we also added +0.5 static caster as a sweetener. The design, size and material used in the repacement bush helps us then acheive up to +1.0 deg increase in dynamic caster.
- Fitment of the ALK DOES NOT lower the rear pickup point to the horizontal (relative to the front) or beyond. Dot green would deliver pro-dive, dot blue is neutral but the ALK locates this point around 2-3mm ABOVE the blue or around 19mm below original.
- To argue against the geometry changes resulting from the relocation of the rear pickup point as claimed by Whiteline is to argue against front anti-dive geometry as designed by OE chassis engineers for almost every contemporary chassis. Again, we just reduce the amount of anti-dive which is inherently pro-lift.
- The claim that reducing front lift by increasing rear anti-squat is symptomatic of "band-aid" suspension cures and leads to sacrificial tuning. That is, losing something at one point to benefit another. The front and rear of 99% of vehicles are "decoupled" and must be treated seperately if possible. A front lift problem should be dealt with at the front, increasing rear spring rate or changing anti-squat geometry does not fix the front lift problem. It just "dulls' it.
We'll be back soon.
All the best.
Jim Gurieff
Whiteline Automotive
[Edited by Whiteline Automotive - 9/20/2002 2:23:56 AM]
20 September 2002, 11:57 AM
#41
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Thanks for that Jim Please note that I have never called 'snake-oil' re your kit, throughout I have said I 'believe' it improves the turn-in and reduces power understeer.
The specific point was the Anti-lift function
This is the area of contention if that helps you ?
I think I can see where you got that from, if you look solely at braking then if you kept increasing anti-dive you would eventually get pro-lift ie hit the brake and the nose of the car would lift. When you reverse the longditudinal force (acceleration) you also reverse the vertical component and anti-dive forces become anti-lift forces.....it follows that any reduction in anti-dive = a reduction in anti-lift.
As a practical experiment (not suggesting this for you Jim) try pulling on the handbrake on a Peugeot 206 (or probably any modern small FWD car) whilst going forward (slowly )....result - **** dips sharply (dive / squat)
Reverse the force by doing it with the car rolling backwards and **** leaps up (lift)
This is an extreme case of pro dive/pro lift built in to the rear of this car to minimise the dive angle under braking, the rear squats as much, probably more, than the front dives under braking, the result is a more stable car as it just gets lower as you brake !!!
Please note that I have never called 'snake-oil' re your kit, throughout I have said I 'believe' it improves the turn-in and reduces power understeer.The specific point was the Anti-lift function
we just reduce the amount of anti-dive which is inherently pro-lift.
I think I can see where you got that from, if you look solely at braking then if you kept increasing anti-dive you would eventually get pro-lift ie hit the brake and the nose of the car would lift. When you reverse the longditudinal force (acceleration) you also reverse the vertical component and anti-dive forces become anti-lift forces.....it follows that any reduction in anti-dive = a reduction in anti-lift.
As a practical experiment
(not suggesting this for you Jim) try pulling on the handbrake on a Peugeot 206 (or probably any modern small FWD car) whilst going forward (slowly )....result - **** dips sharply (dive / squat) Reverse the force by doing it with the car rolling backwards and **** leaps up (lift)
This is an extreme case of pro dive/pro lift built in to the rear of this car to minimise the dive angle under braking, the rear squats as much, probably more, than the front dives under braking, the result is a more stable car as it just gets lower as you brake !!!
20 September 2002, 02:07 PM
#42
I did wrote a long reply, but sod it.
I don't think the ALK is snake oil, I truly believe it can improve the handling of your car. But if and when i buy it, it will be to increase the static castor, to improve handling into and out of bends.
If you're drag racing, fit long soft rear springs at the back and lower the front to the deck.
Paul
I don't think the ALK is snake oil, I truly believe it can improve the handling of your car. But if and when i buy it, it will be to increase the static castor, to improve handling into and out of bends.
If you're drag racing, fit long soft rear springs at the back and lower the front to the deck.
Paul
24 September 2002, 03:51 AM
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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.
------------------------------------
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
Following is a copy of an answer posted on MRT Forums in response to the original question directed to us by Andy F.
------------------------------------
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
24 September 2002, 06:50 AM
#44
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We agree that the changes to geometry as argued by yourself and others is logical and can lead to the conclusion proposed
I look forward to your findings from testing.Andy
24 September 2002, 09:44 AM
#45
Wow,
I will be interested to see the results, especially as it may lead to further improvements.
I wonder (as I haven't checked) if the geometry change effects the wheel rate for the same spring rate? Putting the motion of the wheel more parallel to the motion of the strut at some point. As this may negate the purely geometry related effects.
Paul
I will be interested to see the results, especially as it may lead to further improvements.
I wonder (as I haven't checked) if the geometry change effects the wheel rate for the same spring rate? Putting the motion of the wheel more parallel to the motion of the strut at some point. As this may negate the purely geometry related effects.
Paul
25 September 2002, 03:19 AM
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G'day everyone,
Paul, I'm looking forward to confirming once and for all as well. I'm not certain that wheel/spring motion ration will change much as the relative component is very small. However, Carroll Smith has some interesting things to say about excessive anti-dive and its effects on handling....
:-)
Cheers
Jim
Whiteline
Paul, I'm looking forward to confirming once and for all as well. I'm not certain that wheel/spring motion ration will change much as the relative component is very small. However, Carroll Smith has some interesting things to say about excessive anti-dive and its effects on handling....
:-)
Cheers
Jim
Whiteline
25 September 2002, 11:21 AM
#47
Jim,
Yes, excessive anti dive is not good, I think I mentioned this in an earlier post. Carroll writes some good stuff, for more detailed maths etc, "Race Car Engineering and Mechanics" by Paul Van Valkenberg is good, but Carroll's books and articles are very easy to read.
For racing the watch is generally the final judge, but I have always tried to understand what is going on, so I can try to predict the effects of any given change. You don't always have the opertunity to try all the settings, and have to use your best guess. It's not quite the same trying to optimise your journey to the supermarket though!
Seeing as I have some of your attention, do you do any strut inserts that would be the same size as the OE Kayaba ones?
Cheers
Paul
Yes, excessive anti dive is not good, I think I mentioned this in an earlier post. Carroll writes some good stuff, for more detailed maths etc, "Race Car Engineering and Mechanics" by Paul Van Valkenberg is good, but Carroll's books and articles are very easy to read.
For racing the watch is generally the final judge, but I have always tried to understand what is going on, so I can try to predict the effects of any given change. You don't always have the opertunity to try all the settings, and have to use your best guess. It's not quite the same trying to optimise your journey to the supermarket though!
Seeing as I have some of your attention, do you do any strut inserts that would be the same size as the OE Kayaba ones?
Cheers
Paul
28 September 2002, 05:54 PM
#48
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G'day Paul,
Apologies for delayed reply but I'm travelling at the moment.
I understand what you mean re stop watch, but to ensure consistency an understanding of whats happening is essential I agree. Carroll Smith also has a lot to say re test drivers and how to deal with their feedback.
As for Koni and KYB struts, I'm not 100% certain without referring to a catalogue but if we are talking of earlier series WRX/Impreza, we have some inserts that suit both Atsugi(?) and KYB. Have you checked the Koni international online catalogue? Before they released the newer numbers we used to make spacers for the collars.
Can I suggest you contact wojtek@whiteline.com.au if you need some more information, he can check our files. at the office.
Cheers
Jim Gurieff
Whiteline
Apologies for delayed reply but I'm travelling at the moment.
I understand what you mean re stop watch, but to ensure consistency an understanding of whats happening is essential I agree. Carroll Smith also has a lot to say re test drivers and how to deal with their feedback.
As for Koni and KYB struts, I'm not 100% certain without referring to a catalogue but if we are talking of earlier series WRX/Impreza, we have some inserts that suit both Atsugi(?) and KYB. Have you checked the Koni international online catalogue? Before they released the newer numbers we used to make spacers for the collars.
Can I suggest you contact wojtek@whiteline.com.au if you need some more information, he can check our files. at the office.
Cheers
Jim Gurieff
Whiteline
28 September 2002, 08:27 PM
#49
Thanks for the info, I will contact wojtek (does he have a real name I wonder?).
"g'day" is overated as a the aussie phrase, I found "she'll be alright" to be the defining aussie phrase, but maybe I was too busy breaking my landcruiser.
Paul
"g'day" is overated as a the aussie phrase, I found "she'll be alright" to be the defining aussie phrase, but maybe I was too busy breaking my landcruiser.
Paul
17 October 2002, 04:41 PM
#50
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Guys, coming late to this thread, was a new one started in which Whiteline produced a definite statement beyond the above posts?
Whiteline did you perform any dynamic measurements on the car that you mentioned you may do?
jon
Whiteline did you perform any dynamic measurements on the car that you mentioned you may do?
jon
22 October 2002, 08:29 AM
#52
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G'day everyone,
Jon, we're conducting the first round of dynamic tests this week so we should be able to report on the preliminary results quite soon. The delay is largely due to the fact that I've been out of the country for the last 3 weeks.
We have also arranged another series of dynamic tests a little later on. Anyway, will be back soon.
Cheers
Jim Gurieff
Whiteline
Jon, we're conducting the first round of dynamic tests this week so we should be able to report on the preliminary results quite soon. The delay is largely due to the fact that I've been out of the country for the last 3 weeks.
We have also arranged another series of dynamic tests a little later on. Anyway, will be back soon.
Cheers
Jim Gurieff
Whiteline
21 November 2002, 06:22 AM
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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;
------------------------------------------------------
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.
------------------------------------------
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
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;
------------------------------------------------------
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.
------------------------------------------
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
21 November 2002, 10:52 AM
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Good work!
Whiteline has just soared in my estimation. I'll now buy an ALK or whatever its now called!
Maybe you should publish the spreadsheet on your web site.
Whiteline has just soared in my estimation. I'll now buy an ALK or whatever its now called!
Maybe you should publish the spreadsheet on your web site.
22 November 2002, 12:52 AM
#58
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Thanks to all at Whiteline for their thorough re evaluation and much respect for publishing your findings.
Can I suggest John Felstead and Mike Tuckwood kiss my *** for their comments earlier in this post
[Edited by Andy.F - 11/22/2002 12:55:49 AM]
Can I suggest John Felstead and Mike Tuckwood kiss my *** for their comments earlier in this post
[Edited by Andy.F - 11/22/2002 12:55:49 AM]
22 November 2002, 05:33 AM
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G'day everyone,
Thanks very much for the positive feedback. We would much rather be honest and factual so we appreciate your response.)
We've actually published a copy of the complete report on our website in PDF format. You can download a copy at http://www.whiteline.com.au/reviews03.htm.
I guess suggestions for a more appropriate name would be a good idea :-)
All the best
Jim
Whiteline
Thanks very much for the positive feedback. We would much rather be honest and factual so we appreciate your response.)
We've actually published a copy of the complete report on our website in PDF format. You can download a copy at http://www.whiteline.com.au/reviews03.htm.
I guess suggestions for a more appropriate name would be a good idea :-)
All the best
Jim
Whiteline