Cortina Uprights

My Design Assumptions :

• I could get a friend to make some replica Cortina uprights.
  (Similar to Rorty Designs) or
  I bought some new aluminium ones (e.g. from Rally Designs)
• Wheel and Tyre Diameter is 556mm (195/45/15)
• −1° Camber.
• King Pin Inclination (K.P.I) = 4.3° (Cortina Mk3/4/5)
• McSorley 442 chassis with Locost style mounts.
• Chassis to ground 150mm (6inches).
• Front track width = 1452mm (Sierra − In case I go this route)
• » MK3/4/5 (TC/TD) Ford Cortina Upright Drawings here

Results :

• The top link would be approx 296.5mm long and declined 5.9°.
• The bottom link would be 372mm long and inclined 3.5°.
• A−Arm length ratio : 296.5/372 = 0.797.
• The Roll Centre would be approximately 115.3mm.
• The swing arm length would be 1462.9mm.

Conclusions :

Although the set−up was better than many I’d seen, there is obviously great scope for improvement. For instance, to minimise the large scrub radius, huge front tyres (225+) with a large offset would be needed.

The car would have a medium swing axle length (1m − 1.8m) producing :

• Reasonable kinematic roll centre location.
• Medium roll centre movement sideways for given variation in height.
• Wheel angle in roll mediocre, worst on inner wheel.
• Wheel angle in bounce mediocre.
• Mediocre to bad performance in scrub.

Sierra Uprights »

Seventh Heaven 2nd September 2014