Author Topic: Wheel tracking  (Read 357 times)

David S

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Wheel tracking
« on: November 12, 2018, 10:55:56 »
having had an interesting to at the Sprint this year losing the front of the 1st & 2nd practice laps coupled with the car tram lining/losing the front all the way round the M25, think better get the wheel tracking checked.

Can anyone please advise the wheel alignment/tracking data (Toe n/Toe out / Camber) for the Brooklands Ace?

thanks David


paho

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Re: Wheel tracking
« Reply #1 on: November 13, 2018, 10:17:57 »
Hi Dave,
I was hoping someone would come up with some figures, but for want of a better source there are some figures given in the following thread:
https://www.acownersclub.co.uk/forum/index.php?topic=1903.msg16512#msg16512
However the model year may be significant as the figures given refer to a 2009 model. I had mine (1995 year model) measured recently and the
figures were different. I have the standard wheel dimensions with no uneven tyre wear but it does steer very slightly to the left.

I have a spread sheet with translation of the measurements report and comparision of the measurements (mine and the forum thread) which I will
clean-up and mail to you.
/Paho

P.S. I have mailed you via the members list. As I was unable to attach the spreadsheet to that mail you will have to mail me, via the forum, if you want
a copy.
« Last Edit: November 15, 2018, 19:36:13 by paho »

Max (Allan)

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Re: Wheel tracking
« Reply #2 on: November 16, 2018, 20:12:43 »
Hi Dave

When I extensively modified my suspension many years ago I copied Jaguar setup and set toe-in to 1/16 inch (1.6 mm) and never had a problem with abnormal tyre wear (feathering).

However, having said that car failed MOT last year – inside edge of offside front tyre worn down to plies whilst rest of tyre had loads of tread. Baffled I checked front camber angles - nearside measured 1/2 degrees positive while offside 1 3/4 degrees negative – hence wear on inside edge!!! (Had same problem on rear suspension some 15 years ago – nearside tyre was fine, but discovered carcass plies were showing on offside inside edge. A check of camber angles revealed nearside 1/2 degrees positive and offside 3 degrees negative. Reckon there must have been something wrong with factory build jig!!)

There is no adjustment for camber angle (front or rear) that I know of, so a rework of the front upper wishbones is on the cards this winter, plus possibility of increasing caster angle to improve return action of front wheels.

Max

paho

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Re: Wheel tracking
« Reply #3 on: November 16, 2018, 20:50:09 »
Hi,
I have toe-in left 0° 28', right 0° 20' with no uneven wear on the tyres, they've been on since May 2003.
Caster is 4° 45', 4° 40' respectively. Camber is -1° 10' and -1° 29' respectively.
I have the rear wheel figures too if anyone is interested. Thrust angle should be 0 but mine is -0° 16' at present.
I read somewhere on the forum that shims can be used to adjust the caster, camber and the thrust angle; I havn't reached that stage yet.
I would really like to know the default figures as my intention is to strip the suspension and re-build.
/Paho

David S

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Re: Wheel tracking
« Reply #4 on: November 21, 2018, 14:33:19 »
Hi Paho,

would be interested in what the rear wheel settings you have, as will have all wheels re-aligned.

I have written to David Goose and John Abel to ask if they have the standard settings for the Brooklands, if / when get a response will post the information.

In the UK, Northampton Motorsport offer a wheel alignment for one off cars so the system works out what the settings should be, I have attached the weblink to the page on wheel alignment service that they offer:
http://www.northamptonmotorsport.com/services/wheel-alignment/

David

paho

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Re: Wheel tracking
« Reply #5 on: November 22, 2018, 09:55:35 »
Hi David,
hope you receive some guidance from David and/or John. I've sent you a copy of the measurements from my car today in a "corrected" spreadsheet
translated from Swedish.

I'd love to drive over to UK but I'll have to wait until I've finished investigating how I'm going to replace the suspension wishbones.
Plus wait for the dust to settle around the ferry ports.
BR /Paho

westcott

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Re: Wheel tracking
« Reply #6 on: November 22, 2018, 15:05:21 »
Have a look at the background and find the notes on the yellow page   :)

Or directly at the FB page of AC & Autokraft Cobra's plus

https://www.facebook.com/318737708264414/photos/a.321631677975017/485086068296243/?type=3&theater
Everything should be made as simple as possible, but not simpler!

paho

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Re: Wheel tracking
« Reply #7 on: November 22, 2018, 17:51:24 »
Hi,
nice find! Hope the figures refer to the Brooklands version Ace. Have to digest the figures and compare with the measurements I have.
BR /Paho

Wally

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Re: Wheel tracking
« Reply #8 on: November 24, 2018, 16:43:12 »
I am sorry i can not remember where we got these figures from, but after setting ours within these tolerances we had no undue tyre wear front or rear.

Toe-in, front (°) - Total   0°00' ± 15'
Camber, front (°)          -0°15' ± 45'
Castor, front (°)           4°15' ± 1°
King pin inclination (KPI), front (°)   12°26' ± 1°

Toe-in, rear (°) - Total   0°22' ± 15'
Camber, rear (°)          -0°30' ± 45'

Hope this helps
Wally

David S

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Re: Wheel tracking
« Reply #9 on: December 10, 2018, 15:18:02 »
thanks for all your responses, I also received e-mails from David Goose and John Able.

David stated "When I put new wheels on the Red car I had the tracking set to 0.15° toe in each side so 0.30° total this seems so suit the car with good handling and no tram lining - but as I say not sure what the design values should be."

And John confirmed he used something very similar

So will now take this information and get the wheels aligned