Hi all

In the thread further down the page we have been discussing how to get fantastic steering (because quite a few people are struggling to get beyond the "IVA pass but not good enough" stage.
People have contributed lots of great ideas but we still haven't got a definitive measurement of exactly where the upper and lower ball joints should be in relation to each other.
Would any clever/confident people like to put forward their opinion for length A and/or angle B


Castor diagram

Thanks
Dave

if we know A we can calc Angle B

Surely you define angle A as required and then calculate dimension B to suit the wishbone vertical spacing.

I have just gone through this exercise and purchased the following two pieces of equipment



Description


Description


Tried lots of ways before but these enabled me to get the castor I wanted. I cut all the suspension off the front of the car and welded on new brackets to suit.

HiCost - I'm full of questions - What are those? Where did you get them? Were they expensive? What castor angle gave you the best result?

Dave

Any one got a set of MK Indy wozsher arems that they can measure. this should give us a ball park?

I did mine with an angle of 7-8 degrees, my self centering seems fine

Castor is curious.
On a Lotus Elan and Europa it is set at 3 degrees. On a lotus Seven it is at 5 degrees.
A series 4 Seven I believe(?) is at 3 degrees
ALL of the above cars have 'proven' to handle erm..better than most.

Possibly there are other bindings (?) in the suspension / steering setup that causes self centering to be poor?

Ok - it a long time since I did this type of maths so feel free to find errors.

Assuming an angle of 8 degrees is suitable (angle between vertical and line joining the upper and lower ball joints).
Distance between centre of ball joints (hypotenuse) = 210mm (approx)
sin 8 = A/210
A=sin8 x 210 = 0.13917 x 210 = 29.2mm

Therefore an offset of 29mm seems about right.

I am a bit short of that so I need to move the upper brackets back about 9mm.

Please give comments before I get get the angle grinder out!!!!!

Cheers Dave

Root problem is lack of (virtual) King Pin Inclination designed into the Ford upright a light car needs more KPI than a heavy car. KPI is the main generator of self-centering and steering stability.