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Camber/toe problem with my Altezza


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Them being "offended" is typical of a company who knows their workmanship is being watched..... Anyway how did things go in the end?

 

Didn't have time to go back to him Tony, just got the keys to my new apartment so that sort of took up most of the day, should get back to him before Saturday. So surely he can change the settings to the ones you gave me. Says it will take him about an hour and a half to do it ? :thumbsup_anim:

 

About 90 min is normal for the initial setup..... 30min for a fine-tune. I suppose it depends in the equipment.

 

Good luck with the new apartment by the way :thumbsup_anim:

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  • 1 month later...

So finally got around to getting my geometry checked. i didnt go there with the measurements you gave me Tony i thought i'd let him do his thing and see how it turns out and then we can work from there if needed. I decided not to go to the place i orignally mentioned("Discount Tyres, aka Cowboys!") So i found another good place near by, "Dave McCann Tyres" So i asked him to check my camber etc, it went up on to the raised bench, connected up these things with large dotted panels onto the e wheels and some flash red lights were moving up and down at the front of the car(should have stuck some pictures!) So i got a print out with before and after angles, No scanner nearby ill typr them out!

 

Primary angles before:

Front

Caster left: 7º05’

right: 7º22’

Camber left: -1º22’

right:-1º35’

Toe left: 0º04’

right: 0º08’

total 0º12’

Rear

Camber left: 2º09’

right: 2º19’

Toe left: 0º10’

right: 0º13’

total 0º22’

Thrust angle: -0º01’

 

After

Caster left: 7º29’

right: 7º38’

Camber left: -0º58’

right:-1º02’

Toe left: 0º03’

right: 0º02’

total 0º05’

Rear

Camber left: -1º29’

right: -1º32’

Toe left: 0º02’

right: 0º02’

total 0º04’

Thrust angle: 0º00’

 

 

How do they look Tony? I'll stick up the print out tomorrow if you need it

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The end positions are typical for the lowered car.... In truth this is not necessarily bad since the dynamic gains are reduced.

 

Down side is that the castor is very high so the steering may well feel heavy and we could have a conflict with the camber/castor on the corner but without some bench testing actual figures are impossible to predict.

 

Explanation

On the steer axis during cornering there is a mechanism to maintain as near to 100% tyre-tread contact patch.

 

This is a changing of values between the camber lean and the extension of the castor angle.

 

Maths example> For those that like that sort of thing.

 

Camber Change - If a wheel has positive Castor, then the top of the wheel leans into the corner whichever way it is steered. The change in Camber is approximately:

 

Camber Change = Castor x steer-angle / 60 (measured in degrees)

Example: Camber Change = 6 degrees

Steer-angle = 10 degrees

Then:- Camber Change = 6 x 10/ 60 = 1.0 degree

 

The change in camber that results from positive Castor is beneficial to the grip of both front wheels during cornering, providing it isn't excessive. A negative Castor (top of the steer-axis leaning forwards) changes the wheel Camber angles in the 'wrong' direction during cornering, this is not desirable.

 

Transitions

In a forward position the front cambers will be / \ (looking from the front) if for example this car turns to our left the transition of the camber (accentuated by the castor) will move the camber to \ \.

 

Curve

The gains left and right are dependant on the (adjustable camber) against the fixed castor.

 

If the dynamic positions do not correlate left/right then the angular gain generated against one incorrect camber on the corner will roll the weight distribution onto the sidewall and wear the tyre.

 

Sweep-test for yourself

The castor/camber sweep is something you can observe...And this is how?

 

1> Start the car

2> Drivers window down

3> Stand outside of the car

4> Turn the steering full lock left......And look a the left wing?

5> Turn the steering full lock right.....And look at the right wing?

 

What happened!

You have witnessed the bonnet rotating up-down as you turned the steering from lock-to-lock.

 

The reason for this is that the castor on the inner lock extended forward and by doing so lowered the car in a (simulated turn) "transition", if you take time to look at the attitude of the cambers on each lock you will also see the opposing positions (negative-positive)

 

Summery

Since the castor is a fixed angle you cannot manipulate how it manages the camber on the corner.... But you can manipulate the position of the adjustable camber prior to the corner and the acceptance of this relationship.

 

Another important point to note is that modifications are not generally without consequence..... The aim is to have as much benefit at the lowest sacrificial cost.

 

If in the case of your car you can retain reasonable tyre wear with elevated looks and handling then the rewards surpass the losses.

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Oh my god Tony you know your stuff!! so if i understood you correctly, if i raise the height of my car, tyre wear will be reduced and handling improved? is there anything else that can be done to optimize my setup? Thanks for taking the time to reply. i really appreciate it :thumbsup_anim:

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Oh my god Tony you know your stuff!! so if i understood you correctly, if i raise the height of my car, tyre wear will be reduced and handling improved? is there anything else that can be done to optimize my setup? Thanks for taking the time to reply. i really appreciate it :thumbsup_anim:

 

In truth if you were my customer i would leave the chassis as it is?

 

As we know all the natural adjustment have been exhausted and you have a reasonable-safe-neutral calibration with the benefit of a less fluid suspension and lower centre of gravity.

 

By raising the suspension you would preserve tyre wear but violate the whole principle of lowering the car in the first place.

 

I had a project Tezza that was lowered 50mm and on this car we exhausted the natural adjusters.... We decided to monitor the rate of tyre wear...... I can comfortably say the rate was more than acceptable :rolleyes:

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Oh my god Tony you know your stuff!! so if i understood you correctly, if i raise the height of my car, tyre wear will be reduced and handling improved? is there anything else that can be done to optimize my setup? Thanks for taking the time to reply. i really appreciate it :thumbsup_anim:

 

In truth if you were my customer i would leave the chassis as it is?

 

As we know all the natural adjustment have been exhausted and you have a reasonable-safe-neutral calibration with the benefit of a less fluid suspension and lower centre of gravity.

 

By raising the suspension you would preserve tyre wear but violate the whole principle of lowering the car in the first place.

 

I had a project Tezza that was lowered 50mm and on this car we exhausted the natural adjusters.... We decided to monitor the rate of tyre wear...... I can comfortably say the rate was more than acceptable :rolleyes:

 

 

Grand so. Since getting the coilovers fixed and the car raised slightly to a "driveable height" the coilovers have been a lot better. And now new tyres and geometry checked lets hope all is good. That said the first chance i have an excuse to drive to the UK, ill definetley drop in to you and get checked out! Should i go back to the same place in a while and get the angles checked, in case of any abnormal settling etc?

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Every car i set is offered a free fine-tune... The reason for this is....

 

1> The coils will relax

2> Target data for a standard car is only a suggestion, we are all unique

3> A modified cars setup is totally theoretical, so needs validating

4> If tyre wear is expected i can calculate the rate of wear

 

Most places will argue there's no need to re-check the calibration because any movement will still leave the angles within their checking range..?

 

Explanation

Lexus IS200 front cambers range is> 0 degrees to -1 degree with a ideal static position of -30'. So providing the cambers remain somewhere within that range is considered good enough....

 

Well since i'm a fussy sod and i know it will move from -30, after 2000 miles i put it back there :thumbsup_anim:

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Hey Tony, I brought this over from the other thread since it sounds like you were through in there :)

 

Hey Tony, I'd really like some help too if you're offering.. I've definitely noticed this uneven tire wear on my car, and I'd love to spend the money I spend on tires on more fun things :D

Thanks for the help man!

 

Hello

Do you have any modifications to the suspension or wheel width/off-set?

 

and no, I don't. I'm just running stockies for now! I just got some snow tires on (shudder) and they cost me a pretty penny. I'd hate to see these things wear out like my other tires.

Sorry for the slow response too, I was visiting my grandparents.

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Hey Tony, I brought this over from the other thread since it sounds like you were through in there :)

 

Hey Tony, I'd really like some help too if you're offering.. I've definitely noticed this uneven tire wear on my car, and I'd love to spend the money I spend on tires on more fun things :D

Thanks for the help man!

 

Hello

Do you have any modifications to the suspension or wheel width/off-set?

 

and no, I don't. I'm just running stockies for now! I just got some snow tires on (shudder) and they cost me a pretty penny. I'd hate to see these things wear out like my other tires.

Sorry for the slow response too, I was visiting my grandparents.

 

You have a pm :)

 

Please inform the members over the water that anymore data will only be available to Gold-Platinum members.... Reads a bit harsh but wim is a business however distant the problem :)

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Hey Tony, I brought this over from the other thread since it sounds like you were through in there :)

 

Hey Tony, I'd really like some help too if you're offering.. I've definitely noticed this uneven tire wear on my car, and I'd love to spend the money I spend on tires on more fun things :D

Thanks for the help man!

 

Hello

Do you have any modifications to the suspension or wheel width/off-set?

 

and no, I don't. I'm just running stockies for now! I just got some snow tires on (shudder) and they cost me a pretty penny. I'd hate to see these things wear out like my other tires.

Sorry for the slow response too, I was visiting my grandparents.

 

You have a pm :)

 

Please inform the members over the water that anymore data will only be available to Gold-Platinum members.... Reads a bit harsh but wim is a business however distant the problem :)

 

will do, thanks a lot tony! i appreciate it!

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heyoceanfloor

 

Your welcome :D as is everyone globally but i'm sure you can appreciate calibration settings are time consuming and command a fee.

 

The wim forum is an interactive window opening awareness, sharing problems and results within a complicated field most want to ignore..... Tiss good fun though :)

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I HAD a project Tezza that was lowered 50mm and on this car we exhausted the natural adjusters.... We decided to monitor the rate of tyre wear...... I can comfortably say the rate was more than acceptable :)

That mean you don't love me no more Tony :D

 

Sorry for the past tense..... Problem i have is that my fingers a ten minutes in advance of my brain :)

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one last final question Tony then ill leave you alone. Since a got my geometry sorted if i lower the car a bit for a few days then higher it back up to what it was, will this throw all my angles? Cheers

 

Providing you return the trim height back to the nearest 1mm (front/rear/diagonal) then you are safe....... And oi please don't abandon us now :P

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one last final question Tony then ill leave you alone. Since a got my geometry sorted if i lower the car a bit for a few days then higher it back up to what it was, will this throw all my angles? Cheers

 

Providing you return the trim height back to the nearest 1mm (front/rear/diagonal) then you are safe....... And oi please don't abandon us now :P

 

Thanks for the info! I want abandon anyone!! Plenty of more annoying questions but maybe i should search your forum first to make sure my questions havent been asked already

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one last final question Tony then ill leave you alone. Since a got my geometry sorted if i lower the car a bit for a few days then higher it back up to what it was, will this throw all my angles? Cheers

 

Providing you return the trim height back to the nearest 1mm (front/rear/diagonal) then you are safe....... And oi please don't abandon us now :P

 

Thanks for the info! I want abandon anyone!! Plenty of more annoying questions but maybe i should search your forum first to make sure my questions havent been asked already

 

Good stuff...... Don't worry about repetition, if you have a question....Go for it :P

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