Portland International Raceway
Portland, Oregon, USA
April 13 and 14
Well, I'm still not quite used to the 325. I feel quite comfortable in it, since it's so similar to one of my street cars. But there's a few tings that make me a little less than comfortable when driving it.
Earlier in the month, I did a test-and-tune day at SIR. I wanted to shake the car out, since I didn't get many laps in when my suspension failed. The weather wasn't exactly dry, but it was good enough to wring-out the car for a little bit. Unfortunately, after my first session in the morning, I left my engine running.
I had gotten into the habit of leaving the engine on after coming in from a session because it lets oil circulate and helps cool the car. Unfortunately, I became involved in a conversation with one of my friends, and completely forgot that the car was idling in my pit area. That's terrible news, as the car doesn't have a fan!
Just before my next session, I returned to the car to find it steaming; the needle was just getting into the red, so I shut it down and waited it out. A bunch of coolant boiled over, which was a bit troubling; race cars should run water and water wetter instead of coolant, as coolant is very slick. If it spills onto the track, it's very difficult to clean up--it's worse than oil.
After the test-and-tune day, but before the race, I drained the cooling system. BMW engineers didn't make coolant replacement easy. The radiator has a nice low drain screw which empties about half the system. Coolant from the block is drained by removing a bolt in the bottom of the block, over the manifold. What a nightmare!
The bolt is terribly hard to reach, and once it is open, coolant falls from the engine, splashes all over the headers, and goes everywhere. I had a terrible mess to clean up.
When it came time to fill the car with water and water wetter, I was tired and frustrated. I filled the reservoir bottle full, and didn't bleed the system, since I was afraid that I had already put too much fluid into it. Of course, the fact that I had drained more than ten quarts of water and only added about a gallon of fluid didn't really matter. I wasn't thinking anything through, I guess.
I drove the car around my neighborhood and didn't notice the coolant temperature meter jump, so I figured I Was all set.
Boy, was I wrong! At the race, during my first practice session, the coolant temperature meter rose sharply before the end of the first lap. The car was past the exit of the pits, so I had to take another lap before I could stop. I cut the engine and tried to coast through it, pointing other drivers around me furiously and staying off-line in case I was spewing more fluid.
Because there was still air getting through the car, I didn't peg the meter--but it was very high. I waited for the car to cool, and then began adding fluid. I carefully read the manual this time; I was to add fluid until it came out of the bleeder hole. When working on the car at home, I misunderstood the shop manual and stopped adding water at the first sign of fluid in the bleeder hole.
By slowly adding fluid, I put nearly a gallon more water into the cooling system! By massaging the hoses, I got all the air out of the system and the car fired up without spiking the temperature meeting. I wanted to make sure I was ready (and that the car wasn't damaged), so I asked for a hardship lap. This is a single lap (or two) between practice or race sessions. The stewards and the workers have to go out of their way to allow a car out when they would normally be using the bathroom, resting, or cleaning up their section of the track.
Fortunately, the hardship lap went well and the coolant temperature as lower than it had ever been. Since everyone in the race was pitted in the infield, I'd have to wait a session before crossing if I needed to leave the track to buy more distilled water or parts.
What a lesson! Funny thing was, I felt great: I had discovered the problem, diagnosed it, and then fixed it, all without any outside help. And after all that, the race went very well, though it was rather uneventful. I managed to clock a 1:26.470, which wasn't so bad for driving while staring at the temperature gauge! That time is just less than two seconds behind the front-runners, but I felt very ambitious about finding the speed to cover the gap.
Before the race, we had to switch off my wet set of tires because the weather looked threatening all day. Just before the start of the race, the clouds cleared and the sun came through.
Well, now I was sure I knew how to service my cooling system, and didn't feel badly for making a mistake with the maintenance. I had a wonderful weekend, though traffic on the way home was terrible because there was an accident.