Geometry on a mini

[AlexF]

I know this is akin to breaking the trade secrets act but the mini I am building for track day use is finally starting to come together and I need to have some rough starting figures for suspension.

The spec is:

FRONT: 1.5 negative camber front arms, adjustable tie bars, adjustable ride height (hi-lows), spax dampers

REAR: adjustable camber/tracking brackets, adjustable ride height (hi-lows), spax dampers

So any suggestions for:

Camber
Toe
Castor
Ride height


Many thanks

Alex

[graham bahr]

i have no experience of a mini but have set up quite a few cars, although i guess there should be a lot of mini experts out there that know better but this is where i would start.

ride height, get it so the front lower track control arms are paralelle? with the ground, and just set the rear height so the car doesn't sit at any silly angles.

front toe out 2mm
rear toe 1n 2mm
a front camber of 1.5 neg sounds a good starting point
rear camber 0
if you havn't got the facitity to adjust the front castor dont worry about it at this stage orther wise 3 degrees

[BertMk2]

The homepage listed on my profile is a Mini specialists site (I don't have my own site but I know Bill so I stuck his site on my profile). You could try having a word with him, he should be able to give you a few pointers.

[Chris Y]

Your setup looks a bit like my Mighty Mini, so I'll give you the settings off that.

Front toe: 15 'minutes'(of a degree) out.
Rear toe: straight as possible.
Front camber: 1.5 deg. negative (fixed lower arms)
Rear camber: about 1 deg. negative, or less, particularly when track is wet.
Front ride height: 22cm (measured from the front sill seam)
Rear ride height: 24cm (same again)

We use GAZ shocks, which are 42-point adjustables. Front is set to 15, and rear is 19. My limited experience with fairly old SPAX shocks tells me they are 12 point adjustable, so I would initially try 7 at front, and 9 at rear.

Play about with the tyre pressures and SPAX settings more, in order to get the handling right. Mightys are set up to be fairly tail-happy, which is good for a Mini We run Yoko A539s, and we set them to between 36-38psi, dependant on the track temp, etc.

Set the car up initially for the day, then after a run or two to get used to it, stiffen the rear shocks (2 clicks, maybe 3), or raise the rear tyre pressures a couple of PSI, and see how it affects the handling. Harder rear should make the car oversteer more (tail happy), the same effect can be achieved by softening the front.

I wouldn't really bother playing about with camber on the day, although you could play with the castor a bit, to see how the wheel wants to auto-centre out of corners. Can't remember what mine is set to off-hand, but it's fairly low - you can turn the steering wheel and leave it, and it will continue steering all day on its own

If you can get hold of them before the event, try fitting 5mm rear wheel spacers - they help a lot.

Have fun