Strings need to be truly parallel? I’m not quite clear if they are or not?
I usually just pick a circumferential tyre tread feature and measure across the car with a decent tape measure (assistant required) front and rear of the tyre as high up as the chassis will allow. Never add weight.....
Crude, but seems effective. Your method is better if strings parallel and taut.
Hello Learned Lot
I have been trying to adjust the rear tracking (I had a brain storm and bought 2 adjustable Radius arms)
So this is what I did
I put the car on the ramp with no seats in but 325lbs of sand(in bags)even over the 2 seats.
Then I fixed 2 strings from the ramp so that with the front wheel straight(checked for tracking 12 months ago) 0" to 1/16" toe in
So I set the string 0.500" away at front of tyre and 0.425" at rear and touching rear sidewall of rear tyre.
Then I adjusted the Radius arm so there was a slight gap to the string on the tyre front sidewall(0" to 1/32" toe in)
I bounced the car a few times and had the tyres standing on some old carpet (woolly side down)to allow slip.
Does that all look correct?
The pressure was time rather than complexity. The objective, as the title says, was to get the engine started, but only once all other parts were reassembled to allow the car to be legally driven away!
It may not be the greatest television since 'Civilisation', but it was great fun to do, with good mates, the other Spitfire Aces. See what you think next Saturday.