A compilation of tips for Autocrossing the MKI SC

Alignment Settings    Front SwayBar   Wheels and Tires   Struts   Weight   Recommended Reading

1) ALIGNMENT SETTINGS:

(*) same or slightly less than front
(**) Tommy says these settings are a good compromise for street & track
maximum obtainable camber will depend on whether car is lowered or not. Most Front Toe settings are with BFG R-1 tires. The BFG G-Force requires less Toe Out then the R-1s to acheive the same turn in response.

2) FRONT SWAYBAR

Suspension Techniques, 3-way adjustable. If you have an '88, find a shop that will sell you just the front one (e.g. Ground Control) rather than the set. Be prepared to wait while ST get their act together. Set at full-soft or middle setting. Some have drilled hole between these 2 settings.


3) WHEELS & TIRES

If you are new to the sport I would recommend running on street tires. Street tires don't have the grip, but most will howl and scream as you push them hard. This gives you audible clues as to when you are at the limit. Race compound tires won't give you those clues. They will grip quietly until they lose grip. If you have upgraded to 15" or 16" wheels and still have the stock wheels, then I would suggest getting some inexpensive street tires mounted on them for racing. This is for two reasons. The first reason is that larger rims will automatically bump you into a higher class even if you have done nothing else to your car. The larger rims will also actually slow you down. The larger tire wheel/combo usually weighs more which is not only harder to accelerate, but the extra unsprung weight is harder to control. The second reason is  if you get over aggressive on your everyday tires and flat spot them you will have to suffer the vibrations everyday back and forth to work or replace them. With the extra set on the stock rims you only have to put up with the vibration for 45-90 seconds at a time.

I also believe you will learn to drive fast, faster on street tires.

Race compound tires available and some comments about them.

Most people use 205/55-14 on all four. This helps with the SC's tendency to understeer. Some people have been experimenting with 225/50-14 on their A-Stock (B-Stock in '01) cars. Another choice for Street Prepared  is 225/50-13. 

You'll need to either have your tires heat cycled before you get them, or heat cycle them your self before your first event. Heat Cycling gives your more adhesion and better wear by realigning the rubber molecules. Heat cyclying your own tires is easy to do, but takes some time. All you need to do is have the tires mounted on the rims and balanced normally. Then drive to a big paved open lot and put the tires on your car (DO NOT drive to the lot on your brand new, expensive, unheated cycled tires!). One the tires are on, strap in and do like a skid pad. Go around one way for 10 or so laps and then switch and go the other way for about 10. You are trying to generate even heat into the tires. When you stop you need to feel the tires. They should feel very warm, but not "Hot". Once you have the tires heated, swap tires again and go home. The heat cycled tires now need to rest for at least 24 hours, better to leave them for 48. 


3a) TIRE PRESSURES

BFG T/A R1: 24-30 F, 26-32 R.  Pressure difference F to R should be ~2 lbs. Most others should be around 38-40 psi with the same 2 psi difference.

3b) WHEEL OPTIONS

All MKI's came with 14" wheels, the SC wheels being 6" wide with a 39mm offset. If you plan on autox'ing in stock class then you have to use this size rim. If you have upgraded your street tires to 15" or larger they will put you in Street Prepared. It's very hard to make a SC (or any car) competitive in ASP without spending lots of money. If you do decide to try the ASP waters then you will probably want to go with 13x7 or 13x8 rims with 225x13 R compound tires. The 13" rims will give you much better gearing for better launches.

4) WHAT STRUTS SHOULD I GET?

Koni or Tokico (Illumina) adjustables? Koni has more followers; Tokico are cheaper. With Tokico's set the rear to full firm (5) and the fronts to 3. Let's face it, since any MKI is now at least 10 years old, the struts are bound to be worn out. Even putting fresh OEM struts on will make a great improvement over what is most likely on your car now. I went with the Illuminas because of price. They made a huge difference over my 130K mile OEM units even though I though the OEMs still felt good. 


5) WEIGHT

The stock MR2 SC has a weight bias of 42F/58R. This is great for laying power down out of a turn, but leads to some understeering at slow speeds and a tendency to snap oversteer if care isn't taken in a corner. The snap oversteer is no where as prevalent as with the MKII (even the 93+) but it can bite you. 

One thing to can do is remove some weight at the rear of the car. In Stock classes you can replace the entire exhaust system behind the cat, in Street Prepared you can remove the cat as well. You can build a very light exhaust system for around $35.00. It won't be quiet, but it will be light (about 10lbs vs the stock 50lbs). Since this is at the extreme rear and behind the rear wheels, the effective lightening is multiplied. 

For the ASP racers you can also move the Battery to the bottom of the front trunk. This has many benefits. Doing this lowers the center of gravity. The weight shift is actually double the weight of the battery, as far as the percentage goes. For instance, if the battery weighs 15 pounds, then the effective shift in weight (rear to front) is 30 pounds. This can be done fairly cheaply. You'll need 10' or 15' of some 1 or 2 gauge wire and a marine battery box. Run the positive battery cable through the hump to the front. Ground the battery to the chassis. 

6) RECOMMENDED READING