There seem to be a lot of questions about beginning to autocross. I will hopefully be able to answer a few of these questions. My autocross experience so far has only been with my ’94 GT, so most of the following will be aimed at the SN95 crowd, but some of the advice is universal, only the part numbers may be different. I will break this up into different posts beginning with brakes, going to chassis stiffening, suspension, etc.
First and foremost, the most important item that needs to be done first, are brakes. I cannot overemphasize this issue. Any of you who have done track time will agree, the last thing you want is to feel the carpeting under the brake pedal on the bottom of your shoe as you are entering a turn full boil.
Minimum is a race brake pad. Experience suggests you stay away from the compromise street/track pads such as the “Hawk HP Plus”, they do not do a very good job on the track. The best and safest approach is to run a street pad on the street and change to a race pad on “race day”. For beginners I would suggest using a pad such as the Hawk black pad, they work with brake temperatures from 100 to 900 degrees. With this pad you will not need to worry about bringing the pad up to temperature before it begins to work properly.
After you gain experience and your lap times begin to fall, you can move up to a pad such as the Hawk HT10. This pad works from 350-1400 degrees, so warm up is very important, but it will take the higher temperatures you will place on them. Hawk does not make the HT10 for the rear of the SN95, so you will need to use the Hawk 9012 pad.
If you are running an early SN95 (94-98), you will need to upgrade the front caliper and rotor. For the 99-04 V6/GT I highly recommend you upgrade. The rear setup stays basically the same from ’94-04, V-6 to Cobra. The only difference is that the Cobra runs a thicker rotor, thinner pad, but the same size and diameter as all of the other SN95’s. On the front the 94-98 V-6/GT’s have a single piston caliper with a 11” rotor. The 99-04 V-6/GT’s have a dual piston caliper with the same 11” rotor.
A good upgrade for the front of the 94-04 V6/GT is the 99-04 Cobra/Bullit/Mach I caliper and a 13” rotor. The 99-04 Cobra/Bullit/Mach I caliper’s are mechanically similar. Just the appearances and costs are different. The Mach I calipers are plain black and the cheapest, next up is the Bullit which is red with the running pony emblem (I have these), and the Cobra caliper has COBRA written on them. They bolt right up in place of the stock caliper, the 13” rotor slides right on in place of the original 11”, BUT you will need to run the 17”, or larger rims for clearance. And of course your spare will no longer work on front.
The early SN95’s could upgrade to the 99-04 V6/GT dual piston calipers on front and save a little money. The key here is a little money. If you are going to the expense and time to upgrade, go with the 99-04 Cobra/Bullit/Mach I caliper’s, 13’ rotors and 17”+ rims for the long term. IF, you go with the dual piston calipers, you will need to grind a little of the surface on top of the bolt holes to allow the caliper to mount properly. This is not a big issue and you only need to grind a little off of the mount directly above the caliper bolt holes on the car. There is a “how-to article posted elsewhere on this website.
This is also a good time to replace your brake lines, replace all of the rubber lines front and rear, including the frame to axle rubber line. You will need the front brake lines that match the caliper you purchased. You will need an adapter for the driver’s side flexible brake line to the solid brake line on the early SN95’s. You can go with all rubber lines, upgrade to all Stainless Steel lines, or a combination of Stainless up front and rubber in the rear (which I did). You want to replace all of the lines because the early SN95’s are now over ten years old, the lines will be getting soft, and you do NOT want a burst line on track. Not only can you get hurt, you can take someone else out along with you, AND they will need to shut down the track to clean up the fluid on the track.
For rotors, stay away from the drilled rotors. They may be fine on the street, but they have a tendency to crack under track conditions. This is due to the way they cool, the rotor surface under the caliper when parked cools slower than the rest of the rotor, so the metal is contracting slower than the surface area that is not under the caliper, thus a crack can develop. There are mixed reviews about slotted rotors, they are supposed swipe away the gasses trapped between the brake pad surface and the rotor surface. But, the slots can also “cut” away the brake pad material as the slot passes under the rotor. I had slotted, but they cracked. Due to the cost of the slotted rotor and the fact that they lasted only one plus season, I am personally now going with a solid rotor. Much more cost effective and according to others (I have no track time with solid front rotors) they do an excellent job of braking as do the slotted.
Last but definitely not least on the brake list, is fluid. If you like me didn’t give brake fluid much thought besides adding when low, think again. I never changed my brake fluid and never gave it any thought until I got into autocross. Now I am a fanatic. Change your brake fluid on your street cars per manufacturer’s specs. DOT 3 is fine on the street.
For autocross, for all of you just starting out, a good cost effective brake fluid is Motorcraft High Performance Brake Fluid. It approaches the dry boiling point (500) of racing fluid without breaking the bank. If you have some experience you can move up to a better racing fluid. I would stay away from synthetic and DOT 5 brake fluids. I have heard some not good things about them and I don’t think they are necessary for us amateur autocrosser’s. I use Wilwood® High-Temp 570 brake fluid; it has a dry boiling point of 570.
It is important if you are doing track time to flush all of the old fluid out of the system and replace it with a good high temp brake fluid. You should replace ALL of the fluid after every track event. In my case, we flush the fluid from the front calipers after every track day. You would be surprised how “foamy” the fluid in the front calipers looks after just one day of track time. But, you may not need to flush every track day, because we run the car twice as much as everyone else. We have two people running back to back sessions and with an auto
trans most of the slowing of the car for corners is with the brakes. With a manual you are able to drop gears to use engine braking to help slow the car.
The name brands I have used in this and subsequent articles are not meant to signify superiority over other brands. These are just products I personally have experience with, or which have been recommended to me. Other products from other companies may be equal to, or better than the products I have listed. Please feel free to substitute other brands with similar specifications if you choose.
The information provided here is from my personal experience, from more experienced autocrosser’s, and mostly from people like you who post to this site and others like it to share their wisdom with others. And I THANK YOU all very much for providing a forum for all of us to learn and share for the betterment of everyone.
Autocross brake information 
to attend every weekend, whereas autox, I could. You are right about the S197's. They are by far the best handling stock Mustang ever, despite their weight. Next choice would be a 03-04 Mach I or 99-01 Cobra. All run in SCCA F/Stock class. Get out and run it!
