Suspension Settings

[graves]

With limited equipment, ie no optical gauges etc how does one measure and then set caster and toe angles. I have rebuilt my Rover cooper and took part in my first sprint last october at a VERY wet Lyydon. I am entered for a sprint at Brands in a couple of weeks and am keen to dial out some of the strange handling characteristics i was experienceing with the newly put together car!!

[graves]

Thanks for the info, and the thread. I shall try the 1meter Angle on each wheel trick to set the toe. I beleive 0deg is recommended up front. As for caster, i have managed to source an electronic inclinometer, i was thinking of using two equal length peices of flat bar bolted to the top and botton wishbone points on the upright. With the bars facing towards the front of the car i can put the inclinometer accross the two ends. The angular diference between the ends of the bar will be my caster?? Very hard to explain with text!!

Perculiar handling can be defined by:
1. Massive understeer - very wet, maybe front set too hard?
2. Does not track in a traight line - Tracking out, or crabbing?
3. Turns better one direction than the other - Caster different for each wheel?

Thanks again

[graves]

selbymsport said:

what strange handling? Questions : tyres used and presures? damper type/make, roll cage type, ie bolt or weld in, anti roll bar fitted? suspension joints- rubber/plastic or spherical?

Tires are Yokos 5?? (road tires), i ran with 30psi all round, dampers are spax on back with koni up frt, how do you adjust Koni??, Roll cage is bolt in SD with welded in frt legs at floor with door bars. No anti roll bars. All suspension joints are uprated bush, subframes are solid mounted. Adj camber rr swing arms, 1.5 deg frt lwr arm and adj tie rod.

[graves]

Cooperman said:

The rear end MUST toe in by betweem 3/16" AND 1/8" Peter

Peter, thanks for the info, you quote a length not an angle for Rr toe, where is this measurement taken from? Schoolboy stuff i know!!

[graves]

[quote=selbymsport]
Are you driving the car to the sprints or transporting it?

you can set the caster by using the caster gain method, i.e. turn steering wheel one turn and measure camber then one turn in other direction and add, x the result by 1.4 and this will give you your caster angle (or very near) set this to 6 degrees to start with. You will probably have to shorten your tie bars. [quote=selbymsport]

Thankyou very much for the reply, it makes very interesting reading. I shall be trailering the car to events, predominantly for financial reasons, i dont insure, tax or mot the car. The handling characteristics you describe sound good for the type of use the car will have, i will install the setup you describe. I am very interested in the Camber Gain technique you describe, to reiterate

1. Start with car on flat ground with wheels pointing directly forward.
2. Turn steering wheel 360deg in one direction.
3. Measure Camber
4. Return to straight ahead.
5.Turn steering wheel 360 deg in other direction
6. Measure camber
7. Add two camber values together and multiply by 1.4
8. Caster value!!