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Steering improvements 2
panichat - 26/3/11 at 11:28 AM

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
Castor diagram


Thanks
Dave


mad4x4 - 26/3/11 at 11:33 AM

if we know A we can calc Angle B


Confused but excited. - 26/3/11 at 12:34 PM

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


hicost - 26/3/11 at 12:52 PM

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


Description
Description


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.


panichat - 26/3/11 at 01:52 PM

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


mad4x4 - 26/3/11 at 02:14 PM

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


prelude1980 - 26/3/11 at 03:27 PM

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


Bare - 26/3/11 at 04:42 PM

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?


panichat - 26/3/11 at 06:01 PM

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


britishtrident - 9/5/11 at 04:28 PM

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.