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changing uprights?
number-1 - 26/4/18 at 05:14 PM

Im not a lover of the MK1 escort cut down strut uprights on my car and looking for something a bit more more modern. Ive seen these Rally design ones that are suited to Wilwood powerlite calipers which i have. However they are cortina geometry not escort. Does this matter a huge amount on a kit car?

RD uprights


Theshed - 26/4/18 at 06:41 PM

Yes!

and no....

The wishbone inner mountings are attached in a position that gives the right geometry for the existing uprights and wishbone legnths. Change the uprights and you will change that geometry. The geometry is vital not only for handling but also tyre wear and safety.

It should not be difficult to get a drawing of "cortina geometry" inner mountings and buy or make wishbones to match. - others will know better than me but "book locost" uses cortina geometry if I recall. You can almost certainly easily move the inner mountings.


number-1 - 26/4/18 at 06:51 PM

Cheers for the reply mate.

Im pretty new to the kit car world and wont lie, i dont really get the whole geometry thing as ive never looked into it. Is it in simple...very simple terms....Length of top wishbone, Length of bottom wishbone, angle of upright that joins the both and angle of stub axle?


Theshed - 26/4/18 at 09:24 PM

Sorry I tried to reply and think I accidentally started a new thread!

I had said that geometry is what regulates the way the wheel / upright behaves in roll and bump and both at the same time. Generally with an eye on keeping the tyre as vertical as possible to maximise grip.

If you used the uprights you have found with a proven design it should not be too difficult to graft on to your existing chassis. Starting from a blank piece of paper is harder. I used a computer program to design mine - god knows if it will work well but I do know it will keep the wheels (almost) flat on the road through 4 degrees of roll.

Susprog suspension front
Susprog suspension front


motorcycle_mayhem - 27/4/18 at 03:53 PM

Don't dismiss the Escort set up too swiftly. Heavy and agricultural it may be, but you can pull the assembly out of the tyre wall at Quarry (Combe) and carry on... albeit with considerably less bodywork.

In the picture, Escort cut down on the left, Cortina (in this case a Westfield) upright on the right. Should clearly make the point that the inclination angle between the two is slightly different, as is the vertical displacement of the stub axle relative to the wishbone pickup points.
This was not a problem. I discarded the lower rosejoint, welding on a familiar Maxi balljoint on a plate. The lower wishbone then defined the standout, the top wishbone adjusted with welding on a Transit joint. A spacer made up for the top of the Westfield upright maintained the geometry ('Wishbone' used to calculate it all).
End result gave a 3/4" drop on the front stub axle height (with correct geometry), which was the same as the drop achieved when modifying the rear uprights.