[bobharly]

Over the summer, I went out for a day of auto cross. It was my first experience and I loved it, even if it was 102F!!! I was a terrible driver, and proudly left that day nicknamed the "Cone Killer." After that life got busy, until mid-last week I noticed that SCCA, Cal Club at Fontana, was hosting Autocross School. It was only $147 for a non-SCCA member, for two days! Bargain if you ask me. I signed up and found myself wait listed. So it was until Thanksgiving that my registration was confirmed. I honestly didn't think I was going get in.

So, I checked in and then walked around looking at everyone's cars. Everyone was really approachable and I could talk to anyone about their car or experiences. Next we meet up and found out who our instructor was. Each instructor was paired with two students. While one student works the course or rests, the instructor is working with the other (or getting their rest). At this point we found out the order of run/work groups and went for a course walk.

I was in the first work group, so next the beginners like me had a quick lesson on working the course, like how to mark cones, identify if the cone is a penalty or not, when and how to wave the red flag. After that we were assigned work stations and issued chalk, red flags, walkies and extinguishers. Work was actually fun. It gives you a front row seat to watch how others drive the course, both the good and the mistakes. And how the weather can change the course during the course of the day. Also you learn to keep your head on a swivel, because you always need to know when the next car is coming. Resetting cones was the most hazardous part of the job. I quickly learned that it was better to let the next car pass, than to rush and save the cone. Safety First! I was deeply amused to see that Mustangs kidnap cones when they hit them. Something about their underside? The cone(s) get stuck and taken to the finish line every time!

After, you run you go to a 15 minute debrief to discuss what didn't work on the course and what DID work well. It was a good conversation, however I went rogue and joined two group debriefs that were not my group. I'm not sure what I was even doing when it was time for my group??? Maybe I was eating a poptart? I was tasty.

For my first run session, with my instructor, I set a lap of 60.XX seconds. Then the instructor drove my car to set a "goal" for me that he thought was "achievable" by the end of the day. 53.9 seconds seemed amazing! I had my doubts that I could do that. But I figured if I hit 55.XX I'd be pretty happy. After six more runs, I had spun out once (Both feet in, if you spin!). My last run was a 56.6. Hitting a 55 looked good.

Lunch was catered. Sandwiches and cookies! Soda went fast and I wasn't craving chips, but at least there was plenty of bottled water. I thought that was pretty cool, since I'm pretty sure lunch is not normally provided.

After lunch, work was a repeat. I had chatted up another novice like myself with a RS, also stock like my car. I was watching him closely hoping to match him. But when he posted a 53.5 I knew I wouldn't catch up. He later told me his best was 52.9. The RS performed well. You could see the AWD pulling the car out of the corners and acceleration out the corners was amazing. My favorite cars to watch were the Miatas, the RS, a 1980's Porsche that kept locking it's inside brakes and the old 60's muscle cars. That poor old Malibu on slicks just struggled with oversteer almost every time he passed my corner.

My second run session they made some "minor" changes to the course. We walked the course again, and it didn't look like a big deal. Some cone pointers in the entry or exit of the slaloms were flipped to the opposite side. I was in for a big surprise. Those little changes totally changed those corner entries and braking start/ends. I found myself relearning the course after I was just getting the hang of looking ahead. After two frustrating runs, where tunnel vision was taking over, the instructor offered to drive my car. That helped a lot. Seeing it from his point of view helped me to see that I was still driving cone to cone, instead of looking where I'm going. It's an easy concept, but much harder to do. Back in the drivers seat my times started to come down again. When I matched my 56.6 from earlier, the instructor got out and told me to do it on my own and just imagine he's in the car yelling at me. Feeling confident I went into my next run and I was doing good, in fact I'm certain I could have broken into the 55's, except at the end of the slalom my brake pedal got mushy and overshot my last cone! Then the next brake point the brake was still soft and not slowing me down enough. I didn't look at the time, because I was worried about my brakes. The instructor didn't seem to worried and told me to do my last run. So I went again. At the end of the slalom I began braking early, anticipating the soft brakes and barely made the corner. Then on the next and last tight corner the pedal nearly went to the floor and brakes felt more like a hand brake... I didn't even try to make the corner. I just drove between to cones off course were it was safe to come to a stop and turn around. I was so bummed and a bit worried about my car.

I spent the next 10 minutes doing some cool down laps at the far corner of the parking lot to determine if it was brake fade or boiled fluid. I concluded I had boiled my fluid. Everyone was pretty surprised by this. Which was them promptly followed by everyone sharing their favorite brand of Brake Fluid.

I later concluded, from a comment from the instructor earlier in the day about it "having a diff", that it was the E-differential that had cooked the brakes. Even with the traction control turned off, the E-diff keeps using the brakes to move power from one side to the other in every corner. So the brakes were constantly active. The second factor is that it is the original fluid from when the car was new 4 years ago. So age + constant brake activity = boiled fluid. So I couldn't even go to the second day. But it was worth every penny!!!

 

[gemery]

Yep, with the e-diff, you'll boil the brake fluid in slightly less than 5 minutes of constant autox action. With a little cool-down time, say 5 minutes, between runs, you can possibly stretch to 8-10 runs before it becomes an issue. And that's all with good brake fluid.

Club autox schools at $65-75/day should be able to afford providing lunch.

 

[bobharly]

Ok, maybe I set my expectations too low. I guess getting lunch was very reasonable.

But seriously, is there a solution to the brake boiling??? And what do you mean by "good" brake fluid? I was looking at Motul 600. Temporarily I replaced my fluid with an OEM equivalent, which feels great now. It was just too bad that I spent my second day in the garage, instead of on the course.

 

[gemery]

Well... the obvious solution is installing a limited slip differential (best), stiffer suspension to keep the inside tire loaded, and big brake kits with ducting, but that means money and moves you out of Street. One can also spray water on the discs between runs, which is relatively cheap and leaves you in Street, but not all autox formats leave you the time to do that.

Good brake fluid is fresh and could be any of the favored hi-temp varieties like Motul 600. In my wet Oregon coastal climate, I'm replacing the fluid every 6 months to reduce the incidence of moisture absorption, so at the beginning of the season and then in July before the Packwood Championship Tour (or maybe August if I'm heading to Nationals). If I were doing trackdays, the brake fluid would be replaced before each event.

 

[bobharly]

Gemery:

Thankyou. That's some good info. I was already thinking the LSD would help. So this confirms my thoughts. I had not thought about suspension or brake kits. In the long run, the LSD is my first priority. I rather like stock suspension and a BBK would mean new wheels, so yes the $$$ adds up fast. As a novice, I'm just having fun. So reliability is more important than be class competitive.

I guess, upgrading to a good brake fluid and being prepared to change it frequently will be my short term approach. I'm even thinking to take Fluid, hosing and a bottle with me in the event this happens again so I can drive home safely.

Additionally, my inputs are abrupt and not smooth. I can see this in my tire wear and know that I'm making mistakes and correcting mid-line for them. So the E-diff must be freaking out. I'm hoping as I get better, this will be less of a problem.

I want to pose another question. My current set of tires will probably last till April. As a novice, should I be looking for an autocross tire like RE-71's, or just find an affordable UHP summer tire? It seems to me that until I'm consistent in my inputs, any tire I buy will have a short life span and I am more concerned with consistency and skill, than being competitive.

 

[freakin_elrod]

It seems to me that until I'm consistent in my inputs, any tire I buy will have a short life span and I am more concerned with consistency and skill, than being competitive.

This is the one great self observation of one's self that a lot of folks fail to recognize and you doing so early on will put you worlds ahead as you continue to hone in on your skill.

A lot of folks I have competed with throughout the years have always made the quick jump to the "fastest" tire before truly taking a look at where their actual skillset was. They would become kind of fast as soon as the hot EP tire was on (mainly due to the fact that good grippy rubber can mask poor habits/technique, but soon after, they would hit a wall in terms of improvement, then become discouraged and quit altogether.

 

[gemery]

It seems to me that until I'm consistent in my inputs, any tire I buy will have a short life span and I am more concerned with consistency and skill, than being competitive.

As @freakin_elrod said, you already have a lot of insight for somebody starting out, so you will go far. I would say skip the RE-71R at this point if you don't have a set of spare rims as they're a little obnoxious on the street (tread hum, ride quality unforgiving to tire pressure swings).

One of the locals who finished her second season has been turning up the aggressiveness this year and got to the point this summer where the tires are definitely holding her back. They might have helped her at the beginning of this year, but she's now learned how smoothness helps. We're expecting her to be reasonably competitive next season provided she gets good tires.

Smoothness... it's relatively subjective. I'm easy on tires and look smooth from the outside, but I always warn people riding with me that it is more violent than they expect. Light bulbs usually go off after they've ridden with me, that they're being too smooth too much of the time. On the other hand, there are other people who forget to turn off the aggression when necessary, so they learn to occasionally tiptoe.