Toe in degrees.

[andyelan]

Hi Again Everyone

This was the formular which I was questioning "TAN . 1/2 track difference (front to rear) divided by wheelbase"

Yes I have measured the toe-in at the rear of my car and I got a total of 30 minutes between the two wheels (or 3mm as measured at the wheel rim diameter) this being accurate to better that 1.5 minutes to the centre line of the chassis.

Finally I believe the early Series One Jaguar E-type manual quote toe measurement as taken at the tyre diameter which was the only reason I mentioned it. In this case however it is clearly stated that this is how the measurement should be taken

Regards
Andy

[john.p.clegg]

Andy

The formula "TAN . 1/2 track difference (front to rear) divided by wheelbase" is one I picked up years ago,I know not from whence,but is based on the theory that the four wheels should form a trapezoid for stable driving...the piccy is in the post below...

elan-f15/tracking-t19506.html?hilit=%20wheel%20alignment


John

[Jeff@Jae]

To add to all this I find Elans like some variable from the factory toe in depending on the tires used. Something like the squarish Bridgestone RE92s seem to be better with less toe in and some variables in the taller, skinnier tires like they originally used like a little more than the factory settings.

[rgh0]

This email exchange below with the technical writer from lotus in 2006 explains the way he believed Lotus specified it !

Not quite gospel as he did not write the manual himself
but unless you can find the manual writer it probably as good as it gets
cheers
Rohan



From: Massey, Dave [mailto:[email protected]]
> > Sent: Tuesday, 9 May 2006 1:43 AM
> > To: 'Steve Waterworth'
> > Subject: RE: Elan toe in setting
> >
> > Dear Mr. Waterworth,
> >
> > Toe-in is the difference between the distance apart of the front
> > wheels measured at the front and rear of the wheels concerned. Or
> > the latter, the way you describe it.
> >
> > Hope this helps.
> >
> > Yours sincerely,
> >
> > Dave Massey - Technical Service
> > Senior Technical Author
> > Lotus Cars Ltd., Hethel, Norwich, Norfolk. NR14 8EZ.
> > Tel: +44 (0)1953 608247
> > e-mail: [email protected]
> >
> >
>

[john.p.clegg]

Rohan

What was "the latter"?

John

[bcmc33]

This email exchange below with the technical writer from lotus in 2006 explains the way he believed Lotus specified it !

Not quite gospel as he did not write the manual himself
but unless you can find the manual writer it probably as good as it gets
cheers
Rohan



From: Massey, Dave [mailto:[email protected]]
> > Sent: Tuesday, 9 May 2006 1:43 AM
> > To: 'Steve Waterworth'
> > Subject: RE: Elan toe in setting
> >
> > Dear Mr. Waterworth,
> >
> > Toe-in is the difference between the distance apart of the front
> > wheels measured at the front and rear of the wheels concerned. Or
> > the latter, the way you describe it.
> >
> > Hope this helps.
> >
> > Yours sincerely,
> >
> > Dave Massey - Technical Service
> > Senior Technical Author
> > Lotus Cars Ltd., Hethel, Norwich, Norfolk. NR14 8EZ.
> > Tel: +44 (0)1953 608247
> > e-mail: [email protected]
> >
> >
>

I've seen that before, Rohan, and something different from the same department (not that author).
However, how do you do it on your cars?

[oldelanman]

On the question of where the toe-in is measured on the wheel/tyre assembly, it occurs to me that if you aim to set at the mid point of the spec the measuring point becomes irrelevant. In other words if for instance you set to 3.18mm at the centre of the tyre tread, a measurement across the wheel rim would still be within the overall 4.76-1.60mm spec and vice versa. By my rough calculation for a 13" wheel/tyre there is around 1mm difference between measuring at the tyre tread centre and measuring at the wheel rim - but I stand to be corrected by the mathematicians amongst us.

If you are calculating the toe-in angle and worried about accuracy, don't forget that for a 13" wheel the diameter of the rim edge is more like 14" - not 13" which is the ID of the tyre!

Regards,

[elansprint71]

Cough... any suggestions for rear axle toe-in?

Yes, I have dem bones.

[oldelanman]

Cough... any suggestions for rear axle toe-in?

Yes, I have dem bones.

I have no idea.....maybe you should ask Andy.....

Yes I have measured the toe-in at the rear of my car and I got a total of 30 minutes between the two wheels (or 3mm as measured at the wheel rim diameter) this being accurate to better that 1.5 minutes to the centre line of the chassis.

[quaybook]

I found this:
http://www.fiatforum.com/miscellaneous- ... lator.html
which looks to produce the right sort of figure and is easier log tables or trying to find my slide rule.

Vernon

[rmd24]

Hi Vernon,

I'm sure that calculator is just the answer I'm looking for. Unfortunately it's an xls file and I don't have Excel on my computer. I can open it in a read only format but of course that doesn't help me do the sums!

Roger.

[alan71]

You can use Open Office, and it's free.
http://www.openoffice.org

Alan.

[rmd24]

Open Office enables you to open and read the file, but it's read only so you can't do the calculation, unless I'm missing something.

[elansprint71]

Damn; that's clearly why Lotus lost so many F1 races back in the 70s; they could not open the Excel files.

[bcmc33]

Open Office enables you to open and read the file, but it's read only so you can't do the calculation, unless I'm missing something.

I know nothing about Open Office, but I would think that if you opened a new file, copy and paste the sectors, and save it as an Open Office file it should work.