Quick ratio steering rack for G T Racing chassis (ex MDA kit)

Takis M.

Supporter
Does anyone know which quick ratio steering racks can be used with the G T Racing GT40 kit (ex MDA kit)?
I would like about 2.0 turn to turn or thereabouts (without limiting the degrees of turn) but also without introducing bump steer.
Any ideas?
Thanks.
 

Mike Pass

Supporter
Remember that a quick ratio steering rack will be heavier on steering effort. A GT40 with big sticky front tyres and a normal rate rack will be heavy at low speed anyway unless you go to power steering. The usual power steering rack used on 40s is the Vauxhall Corsa electric one.
To eliminate bump steer from scratch is a complex business. The simple way is to ensure that any replacement rack is the same length as the original and has the steering arm ball joints in the same location. Otherwise try to ensure that the wishbone pivot points and the steering rack arm ball joints are in the same plane.
For racks try this place

Cheers
Mike
 
The Mk1 had 2.8 turns lock to lock with 37 ft turning circle, Mk2 had 2.25 lock to lock with 34 ft turning circle, Neither had P.S. options and the turning circle would depend on tire width/dia along with wheel offset. You need to consider all these and other factors when contemplating your 2 turns lock to lock rack.
 

Takis M.

Supporter
Ok. More complicated than i first thought.
Thanks Mike, thanks Jac. I have written to Kiley Clinton and waiting their reply.
Meantime even 2.25 lock to lock would be ok (provided improved turning circle).
I will Keep you advised if I learn anything new.
Thanks guys.
 

Glenn M

Supporter
Ok. More complicated than i first thought.
Thanks Mike, thanks Jac. I have written to Kiley Clinton and waiting their reply.
Meantime even 2.25 lock to lock would be ok (provided improved turning circle).
I will Keep you advised if I learn anything new.
Thanks guys.
Just to add to the complications, as Jac points out, you cannot compare steering turns lock to lock between different cars/manufacturers which have different pick up points, geometries, wheels and tyres. For instance, I do know that my Southern GT has a tighter turning circle than a GTD.
Like you, I too decided that I wanted quicker steering but could not find an aftermarket rack of the correct length (ie to not affect the complete lack of bump steer on the SGT), so I went the route of having a new rack and pinion made to fit the same steering rack. It is now a perfect rate for track work, corrections are now just the merest flick of the wrists, but using your specs you would disagree as it is 2.5 turns lock to lock, but, as I said, it has a large lock, small turning circle.
Interestingly, despite being quick, I do not find it overly heavy manoeuvring and parking (my other half drives it too without problem), which leads me to say that in my experience, with my car, I do not understand the need to fit power steering. I guess it just proves the point that they are all different.
Incidentally, I wouldn't expect that changing the rack will improve your turning circle, normally it is the wheel/ tyre fouling which limits it. What rack does the MDA use as standard?
 
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