3 replies to this topic

[jeffm5150]

Hi all -

If this is the wrong place for this post, please disregard and, if possible, point me to a better place to get this information.

I'm looking for a set of camber, caster, and toe alignment values (for the front end) to use as a good starting point for road racing a Mini. I have massive tire wear on the front tires. After 14 15min track sessions I have corded the front tires on the inside, yet there is still 2mm of tread depth on the outside (just inside the shoulder).

My current alignment setup: note that the camber and caster values were provided by the alignment shop that performed a full front end alignment within the last month.
toe: 1mm toe out
caster: +3 deg
camber: -1.5 deg

My car info:
1973 Austin Mini 1000
Quaife mild LSD
10" genuine Minilite 10x6 wheels
165-70/10 Hoosier HO-TDS tires
fully height-adjustable suspension with stiff springs
koni red adjustable (rebound damping only) shocks - 1 click less than full hard on front, 1 click more than full soft on rear)
no front anti-roll bar
adjustable rear anti-roll bar set at medium stiffness
KAD 7.9" rotor brakes

The very soft Hoosier tires are 31psi hot off the track. I have read some here about needing MUCH higher pressures but here in the states (I live in Arizona, USA) most of the vintage racers that run these Hoosier HO-TDS tires want them 30psi when hot.

Any help would be greatly appreciated. I get conflicting info that the camber is the cause, and from other people that it's the toe out. The workshop manual indicates 2mm toe out is the correct setting but I've been told that that's _way_ too much for road racing.

Thanks TONS. This forum is the bomb!
Jeff

[RandyBMC]

In my experience, 1/8" total toe out works without trashing Hoosiers, but 1/16" toe out should be good. I used to run them 36-40psi hot depending on front or rear and if I wanted under or oversteer issues sorted using the pressures. I would say the camber is fine too at that small of a setting. -2 degrees is what I am currently running, with as much castor as I can get. The workshop manual states 1/16" total toe out front, 1/16" toe in rear.

Hope that helps.

[jeffm5150]

Thanks Randy

Two weekends ago I changed out a frozen front left suspension arm and quickly checked the toe with a crude "measure back of tires, measure front of tires" method. I got an apparently inaccurate reading of 1/32" toe out (as I posted above). Since my original post I performed a more accurate string toe alignment check and found the left to be toed in 1/8" and right toed in just under 1/4", and I'm confident of those readings. Wow, my toe was _way_ off. I guess that's the likely culprit since every revolution of the tire is grinding tread away, and with the negative camber, it's eating away the inside edge more than the outside edge. That was a costly mistake for sure.

One other question Randy - when you were running Hoosiers what was the longevity you could expect from them? I've heard as much as more than a season and as little as just over one track weekend. Specifically the fronts, since the rears don't seem to take the aggressive loads that the fronts do.

[racingbob]

i ran hoosiers on my historic racer in australia in the 90's

26 f 24 b if i recal on 10" rims ( cold )

that setup looks fine i ran 1.5 camber 5 caster 1/16 toe out