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Locost Caster Setting
Neb - 1/11/13 at 09:39 AM

Morning,

Our MK Chassis requires the front suspension pick ups to be chopped off and re mounted to suit the wishbones i bought from Rally Design a few weeks back. They are non adjustable other than for camber. Unfortunately the wishbones that came with the chassis are not much kop. We are using Cortina hubs for reference.

My question is i'm about to chop the brackets off, the book says 5deg & 30mins of caster which will be fixed. Is this the best setting?

If anyone has some dimensions of the bracket locations when looking from the side of the chassis on a Locost it would be hugely appreciated. It's something i'm unable to find in my Ron Champion book!


Not Anumber - 1/11/13 at 02:49 PM

A quick search of this forum will reveal the lack of caster is a known issue for MK Indys and is quickly and fairly inexpensively resolved by fitting adjustable top wishbones.
though someone could go to the trouble of grinding off and welding on new wishbone mounting points and then buying another set of fixed wishbones why would you want to do that ? Apart from the concerns about welding new mounts to a section of chassis that has previously been welded to you only have one shot at getting them optimally positionned. With adjustables you leave the mounts where MK put them and adjust the caster on the wishbones and keep tweaking until the car drives with the right amount of steering self centre. right. Personally i wouldnt be guided by the position of the mounts on the Ron Champion car or any other 7 as suspension geometry is not the same.


Bluemoon - 1/11/13 at 05:01 PM

but it's not an indy... It's a mk locost..


doobrychat - 1/11/13 at 05:11 PM

i too chopped mine off but fitted rose joints to make it adjustable.. had some inserts made up and welded them in..


ashg - 1/11/13 at 09:43 PM

position of the brackets is critically important get it wrong and it will seriously ruin the car. get a copy of competition car suspension read it then make an educated choice about where to put the brackets rather than just mess up your car by guessing.

its only £16 on Amazon and a couple of days reading will save you so much bother



http://www.amazon.co.uk/Competition-Car-Suspension-Practical-Handbook/dp/1844253287/ref=la_B001JP3QZQ_1_1?s=books&ie=UTF8&qid=1383341842&s r=1-1


Neb - 4/11/13 at 03:59 PM

Thanks for the input all. Many thanks to the link to the book.

I think what I will do is as I previously intended to do by removing the brackets and re-welding new, but make the upper brackets a few mm wider either side to be able to add spacers to bring the upper wishbone fore or aft as required. All will be triangulated where possible.

I'll stick to the 5deg + to start with as I can measure that by using a datum or maybe a jig if required. I'm happy that the chassis is pretty straight. If when we get the car rolling we feel that adjustable uppers are required then we will engineer some.


907 - 4/11/13 at 06:20 PM

On my Locost I remade the top w/b's and added 13mm of extra caster, making 22mm in all.

Check this recent thread out. http://www.locostbuilders.co.uk/viewthread.php?tid=185670


An odd washer or two is not going to be enough.
I would move them while you can. You will be surprised how much you need.

HTH
Paul G