Wheel base dimensions

[Tony]

I noted when tracking the car that the rear axle dimensions is 3/4” narrower than the front wheel base. I had a full fuel tank. The measurements taken where from the face of the spinners. Should I have the same dimension both on the front and rear.
Could this be due to loading on the back axle not spreading the half shafts out enough.?

[AussieEtype]

You have not said what etype you have and I assume you are talking about front and rear track rather than wheel base.

Series 1-2 Track = 50" front and rear - so the same.

Series 3 Track front = 54.375", Rear Track = 53.375"

So if your car is a Series 3 would seem normal.

[christopher storey]

Tony's car is an S1 3.8. However, it has 205 tyres , and the wheels may be non-standard with ( possibly) a different offset from standard, which almost certainly would affect track, although you would expect the alteration to be the same front and rear . Generally speaking, for absolute accuracy the car needs to be in the mid-laden condition ( see K15 in the workshop manual) but I would not have thought that being higher or lower would affect track that much, although it would affect camber

PS ...and, of course, unless the spinners are absolutely identical that might well affect measurements

[Tony]

You are correct I have not stated which car I have, so I will correct that. The way I obtained the measurements was to run two parallel lines down either side of the car at the height of the spinners. When I measured from the lines to the centre of the spinners I noticed the difference of 3/8 on either side with the rear track being smaller. As Christopher stated it could be spinners or the wider wheels.

Ps. Christopher. I took the car to Heswall Tyres for tracking but they could not get the kit onto the wheels as the spinners got in the way. So I resorted to using parallel lines either side of the car and plumb bobs for the camber. The steering now feels a lot more positive in a straight line.



1962 E Type Series 1 DHC.

[AussieEtype]

So on the assumption that the front and rear tyres, wheels and spinners are the same, then front and rear track should be the same even if tyres, wheels and spinners are different from OEM as long as front and rear are the same.

[cactusman]

Just out of interest I watched a mechanic setting the caster and camber toe in On a race cooper. He set up a frame right around the car with inch square steel tubes level with the centres of the axles (car on its wheels) and spent a while setting it exactly rectangular and even spaced. He then used a ruler, protractor , plumb bob and calculator to calculate and set all the geometry settings he wanted. I asked why not use a laser set device - there was one available - his reply....'this is far more accurate and is how F1 teams do it". So lines on the floor and a plum bob...excellent!