Competition Suspension Geometry

PostPost by: +2R160 » Thu Dec 11, 2003 2:41 pm

I have recently fitted my +2 with stiffer/shorter springs front and rear, as well as a competition 'quick' steering rack. I would like some advice regarding ideal fast road/hillclimb (solo 1/2) geometry set-up from any racers out there. I am using standard +2 wheels with relatively soft Avon CR6ZZ 185/70/13 tyres. I have set the toe-in to 15' total, while I attempt to shim the rack. Negative camber has increased front and (more signicantly) rear with the lower ride height, but I have no exact measurements yet. I am considering adjustable rear A-frames so I have control of toe/camber at the rear also, but adjusting the ride height will obviously give me some control of camber angle for now. Any advice much appreciated.

Regards, David.
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PostPost by: rgh0 » Fri Dec 12, 2003 11:28 pm

David

I would not be to worried about the negative camber at static ride height as you lower the car. Ensuring you have the right amount of toe in front and rear is much more important.

I run my Elan level front to rear and at 120 to 125mm ride height at the front cross member above the ground on 185/60 x 13 Hoosier street TD tyres. The rest of the geometry is standard without adjustable links as these are not allowed in our historic racing category. This results in greater negative camber due to the lower ride height, about minus 1.5 degrees front and minus 2 degrees rear. I run front toe in of 5 mm which is just above the top end of the specification to give better stability under high speed braking from 200 kph plus speeds

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PostPost by: paros » Sun Dec 14, 2003 5:14 pm

hi
I use Yokohama A032r for racing on 5.5 rims from Minilite. The cambers need to be 2.5 degree at front otherwise temperature across tyre is wrong, less camber and you end up with outside of tyre too hot and car slides making underster worse. I also run 5 mm toe out to give good turn in - horrible to drive in roads like that. rear needs to be about 1 deg negative. Front negative tweaked by file on top wishbone and slotting the 5/16 bolt holes by more than you think!
Spring rates for plus 2 I don't know as mine S4, but assume about twice Lotus standard, keep rear softish so back moves around a bit.
Richard
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PostPost by: davidholroyd » Fri Oct 15, 2004 1:56 pm

<a href='http://www.gglotus.org/ggtech/26rmanual/26rmanual.htm' target='_blank'>http://www.gglotus.org/ggtech/26rmanual/26rmanual.htm</a>

Original set up of a race Elan... thank you Golden Gate Lotus Club..

ps On a standard car keep the ride height standard ..
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