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Does any one know the toe-in on a TR7 in degrees.

I know it's zero to 1.5mm so that would be zero to ???? in degrees.

TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

The BL manual only shows the setting as zero to 1.5mm or 0.062 inch. Someone will know what that translates to, I'm sure!

Tony

1980 3.5L V8 DHC Regency Red - on the road again.

Hi, F1, I think you'll find that the reason its expressed as so many
mm, or fractions of an inch, both over about an 18 inch span, is
because the angle is too small, in degrees, to be meaningful, or
measurable with garage equipment.

I spent many years playing with steering systems, of different
types, with different linkages, of different effectiveness between
the wheels. I came to the conclusion that the manufacturers wanted
the minimum toe-in that would prevent the system producing toe-out,
when under moderate braking.

Braking causes the wheels to try to toe-out, & it doesn't take much
wear in multi link systems, to cause rapid wear of the inside of the
tyres, even if the thing measures OK when static. That's why
different systems require different toe-in settings.

Hasbeen

PS. If you want the angle, start from a piont, [A], & draw a line 18
inches long. Make the end piont [B]
Measure up, at a right angle, 1/16Th of an inch from [B], & make
point [C].

Draw a line from [A] to [C], & the difference between the 2 lines is
the angle. You will need a sharp pencil, or you won't be able to see
it.

H

Thanks for the explanation Hasbeen. Toe-in for braking makes sense, hadn't thought about it that way. I had always assumed it was to keep some tensions on the steering components (to take up any wear) so it is more positive.

anyway I found and Excel program where you plug in the values of toe-in in mm and wheel (not tire) size and it calculates the degrees. Using the 1.5 mm and 13" wheels it comes to .13 degree. Seems awfully small I don't know how accurate todays systems are.

TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

Went to my local tire shop and looked up toe in for TR7 on the alignment computer. It's .14 degrees so the xls formula of .13 is pretty accurate. However they wanted $65 to check and adjust toe-in.

I've set it up using the string around the rear tires up in line to front tires and measure the distance from front side of tire to string. Turn the wheel so space is same on both sides measured with calipers. The space was 2.5mm each which is the difference between rear and front wheel width (5mm). Shortened tie rod close to one turn and distance between string and wheel is 3.25mm. (2.5 + .75).

It seems to drive and handle good. Initially when I got the car the toe-in was set a lot more than it is now. Has anyone done the string setup method? (read about it on another website.)

TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

FI, your method depends on your figures being correct. My figures
tell me the front track is 5mm wider than the back. If your figures
are correct, its fine, if not, its probably close enough to make no
difference, anyway.

Your string method is an addaptation of what all racing cars used
before computers, & lasers maed it into the workshop. The full
method, was designed for fully adjustable front & rear suspensions
was similar.

It required 2 parallel strings, with the car central between them.
The process is then similar. It takes a great deal more setting up,
& will check if your rear end is correctly alligned with the front.
I don't suppose that matters too much, when the only correction
involves welding.

Hasbeen

I made a v simple track gauge from 'Dexion' angle - it gives the same reading every time so I think it works ok!!

I should probably get my TR out of the garage- I haven't driven it in 15 years! Back when I was autocrossing it, I disassembled the front end many times, and always set it using the string method. Never had a problem. I also made a giant set of calipers out of 1x2, with some screws on the ends for touch points. It took two people to support it stress free, but it worked great. I always trusted it slightly more than the string method.

Yes, Conrad,

It might be time to take it out for a spin!

A potentially daft question........

I'd expect to have the tracking checked if I changed a front suspension / steering component. Should I have to do this if I only change the front springs? I thought the geometry kept the toe in constant.

I think my ageing Triumphtune Sprint spec front springs have finally sagged to the point where there's little suspension movement before the shorter than standard Triumphtune bump stops come in to play. There are speed ramps everywhere in my neighbourhood, nothing scrapes the tarmac but the front suspension bottoms out too easily.

Thanks,

Adam

The ride height does affect the camber and toe but by how much?.Steve.

On this subject, can i ask, if you take the tr7 into get the wheel alignment done, what do you tell the mechanic (technician ) to set the gauges to ??

I have always had great tyre ware and never had the need to get it checked, but i am going to renew the front suspension, ball joints track arms etc very soon and was wondering what the setting were.

sonscar wrote:The ride height does affect the camber and toe ...

Add the castor angle

stevie_a wrote: ... wheel alignment ... what do you tell the mechanic ... to set the gauges to ...

As per the book, well almost ...
• Toe in 0 to 1 mm;
• Castor ± 3½° (a fair amount of work to get this set up properly)
Camber angle is slightly more difficult to set up properly with the standard suspension set up ...

Thanks Beans