...what would you set the front/rear toe and camber for best autox performance? I have seen some recommended alignments posted already but all of those were for cars with upgraded shocks/springs and sways.

My Car:
2004 MINI Cooper SS+
15" Holies with 205/50/15 Azenis 215 (will go to R compound next)
No Mods

I am buying RDR camber plates and rear control arms that should give me a wide range of adjustability for toe and camber. Assuming I do not upgrade anything else (all shocks/springs and sway bars stay stock) what should my autox alignment be (75% autox and 25% road)? My MC pushes a lot right now so, ideally I want the car to be more neutral which will allow me to dial in rotation using tire pressures.

 

Those mods will put you in STS which doesn't alow R compounds. Unless you are willing to go all out on the suspension mods your money would be better spent on a set on a set of Rota Slipstreams 16x6.5 et45 and some 215/16 V710's. Keep the car in H-Stock.

 

Toe is already adjustable from the factory, unfortunately camber is not (at least in front). James is giving good advice though, as nice as adjustable camber would be, it will put you into a class where a lot more money is required to have a chance at being competitive. Either just swap a set of 205/50-15 Kumho V710's onto your stock 15" Holies, or go with a 16x6.6 wheel with V710's. Even in stock trim, I an easily "dial in rotation" with tire pressure. That's why many GS and HS people run significantly higher rear pressures.

-Keith

 

I appreciate your warning and I would most definitely not be considering these mods if i was running in standard SCCA events. I am entering my second full season of autocrossing this spring and I have yet to attend an SCCA event. I regularly race with BMWCCA, Porsche, NASA and M-Club in the New Jersey region, where classification rules are drastically different. The only club that carefully inspects my car and classifies me (using points for mods method) is the BMWCCA. I am currently at the bottom of my class as far as mod points go and have enough room to add race tires and camber without getting bumped a class higher. Driver skill is #1 on my things to improve list (trying to enroll in Garfield's autox school), but I am also tired of using 50% of my tire at the autox - not only does that make me slower, it also kills my tires considerably sooner. I hope that explains why im considering R compounds with susp mods.

Getting back to the question at hand - can you or anyone else out there comment on what my autox alignment settings should be? MC SS+ Holies.

I was thinking about starting with:

FRONT / REAR
Toe 1/16" out / zero
Camber -2.25 / -1

Will that result in too much rotation? I do drive the car 100 miles a week to work.

 

Probably something in the neighborhood of the following:

Front
-2.2 to -2.3 camber
1/10th to 1/4" toe out
about 5 degrees of caster, maybe a bit more

Rear
-1.5 to -1.7 camber
zero to 1/8th toe out

If you install a stiffer rear sway bar, the rear settings would probably move to -1.7 to -1.8 camber and a touch less toe, but not toe in.

Scott
90SM

 

Scott, would -1.5 camber in the back keep the rear a bit too planted?

 

You can tune out rotation on the street with tire pressures (and adjustable struts or rear sway bar if you have them). On other FWD cars I've autocrossed, I've had from -2.0° to -3.0° camber in front, and -.5° to -1.0° camber in back. Toe settings in front were 1/16" to 3/8" to out, but much more than 1/16" toe would start to drastically affect tire wear, I typically ran 0 toe in the rear. Just having very litle negative camber in back doesn't equal snap oversteer on the street (or anywhere else).

 

The toe settings should help with that, plus your front tires will have far more grip once you add the camber to the front. The whole point is for the rear to have slightly less grip than the front. By adding increased negative camber to both ends the total potential grip level goes up compared to stock. My guess would be that something close to these settings will let your car break away at both ends at the about the same time with neutral throttle and smooth steering input.

That allows you make the car rotate (and control that rotation rate) with throttle inputs. Using the same approach (though slightly different numbers) I can easily get 90+ degrees of rotation by lifting off the gas sharply at 1st gear speeds. At higher speeds it's easier to get less extreme rotation by coming off the gas a bit slower. Reapplication of the throttle and some countersteering catches it in both situations.

You can always fine tune things to your liking by fiddling with rear tire pressures. Just make sure that you get the front grip levels as high as you can first.

Scott
90SM

 

OK, based on what I am hearing so far, I am thinking:

Front
-2.25 Camber
1/16th Toe Out

Rear
-1.5 Camber
Zero Toe

 

90STX,

How are you adjusting caster? Everything that I've read suggests adding a little more caster as negative camber is added - up to a point. This apparently brings a little more stability and or feel into the steering - which higher negative camber values can remove.

 

Adjust caster? With camber plates (most styles allow adjustment, certainly the K-mac I'm using now do) you just shove the top of the strut towards the back of the car. I'm pretty much maxed out on camber for my current setup, and still within the factory spec for this measurement.

Like any alignment setting you can theoretically go to far, but I don't think 4-5 degrees on a MINI is too far.

Did I miss something in your question?

Scott
90SM