Track Worthy

Track Worthy

The purpose for this little gold '84 318i was simple: track car. The first step to getting it on the track was making it safe and reliable. Fast was something to worry about at a much later date. While I knew that making the car a reliable track machine was going to be a long process, there were several tasks to concentrate on initially.

The first thing I did was bring the car to Strictly BMW, the local independent bimmer shop. I had them do a "track inspection". They found several items to work on. One of which, the rear transmission seal, I ended up paying them to do -- it sounded like a ton of work, requiring expensive tools that I didn't have. While they were at it, they replaced some of the plastic shift-linkage bushings. This improved the "loose" feeling of the shifter a little, but in the future I'm planning on buying an aftermarket short shifter kit to fix this problem more permanently.

The first work I did was an oil change. This was pretty easy -- following the instructions in the Bentley book, I drained the old oil from the car, replaced the oil filter, and refilled it with 10W-30 synthetic oil. If you don't know anything about oil (I didn't) the numbers indicate the weight, or thickness, of the oil. Oil rated with two numbers has different weights (that viscosity thing they talk about in commercials during football games) based on cold and heated temperature. You want a low friction, light oil when the engine is cold (that's the "10W" part) and a somewhat thicker, and more protective, oil once the engine is warm (that the 30 part). I chose synthetic oil because, even though it tends to leak more (because it's more slippery than dinosaur oil), and is more expensive, it tends to break down less at high heat and is "slicker" (i.e. less engine motion become friction – therefore heat). The oil change process is one that I've gotten very good at with the 318i – I change the oil and filter every other track event on the premise that oil (even synthetic oil) is cheap and the whirring metal bits in the engine are quite expensive. Plus, it gives me a warm, happy feeling knowing that the oil in the car is clean as can be.

Next, I did the most important thing you can do for any track car: brakes. If you can't stop your car reliably, you shouldn't be on the track (for that matter, on the street). Brakes for track driving are super-important. Because you use them over and over again, really hard, they generate a ton of heat (that's what they're designed to do: turn kinetic energy into heat energy). After a certain point – a relatively low temperature for "street brakes" – the brakes begin to function poorly, and eventually won't stop the car at all. That's bad. There are a number of things you can do to you brake system to mitigate this problem.

The first and most important step is new brake fluid. Old brake fluid gets "worn out" because of air and water that has slowly, over time, accumulated in the brake lines. This lowers the boiling point of the brake fluid. I chose to use the ATE "Super Blue" brake fluid because it's designed for high-heat applications and has a higher boiling point than other brake fluids. It also is a really cool blue color. Why is boiling brake fluid bad? When the fluid boils, your brake pedal gets really mushy – the hydraulic properties of the fluid are greatly reduced, and so it no longer translates the energy of your foot moving (and the vacuum-based brake booster – that's the big round black thing mounted on the firewall on the driver side) efficiently to the brake caliper. When the caliper's ability to "squeeze" is removed, the brakes no longer translates kinetic energy into heat energy, and the car won't stop.

To change the brake fluid, I used a $45 pressure bleeder ordered from BMP. While messy, this works fine. I put the bleeder on the master cylinder to create pressure to "push" the brake fluid through the system. Then, starting at the right rear brake, and working progressively closer to the master cylinder, I opened the small valves and bled the fluid through surgical tubing into a container. I bled the fluid until it was clear and then some more to be sure. Like changing my oil, I've gotten quite good at it, as it's something I do every other track event. Because this was the first time I had bled these brakes, I did the complete process twice in order to flush out as much of the "gunk" as possible.

The next thing to do was brake pads and brake rotors (Pads are what the caliper squeezes against the rotor). Like brake fluid, they need to work well when hot – and they will get very hot on the track. The first step was to take the calipers off. The E30 calipers have two large (19mm) bolts that mount them to the strut. The bolts on these were locked incredibly tight with corrosion. I grunted and groaned and swore, but wasn't able to get them to budge. Then I remembered what that Greek dude said: long lever and place to stand = easily removed caliper mounting bolts. Paraphrased. I also cheated by squirting a ton of WD40 on the bolts and letting them sit for several hours while I ran to Sears and bought a breaker bar. To increase the length of my lever, I threw a bit of hollow pipe on the end of the breaker bar. This time when I cranked, the bolts came right out. Two lessons learned for the novice mechanic: WD40 is magic and leverage is a good idea.

I hung the calipers off the strut-springs with a bit of twisted wire hanger. With the calipers off, it was a matter of pulling the old pads out and removing the rotors. For replacement pads I made the mistake of using the no-name set of extra metallic pads that had come with the car. Ugh – what I was I thinking? It seemed like a good idea at the time...

For rotors I chose the ATE power disk rotors for much the same reason as the pads – they were very cheap. While I'm not sure it's worth anything, they had the cool gas slotting to make them look really "fast".

There were also a number of items I replaced or checked, including: all of the hoses – fuel and coolant both, engine mounts, v-belts (those are the little thin belts on the front of the engine), fuel filter and the rear shock mounts. I worked on the principal of replacing it if was at all worn. The last thing I wanted is what might be a very expensive and at very least hassle-laden failure on the track of a $5 part. I think I generally did a pretty good job, as I only had one mechanical "DNS" at a track day the entire following year out of 15 track days (it was, naturally, a $5 part – but it didn't happen at the track). All of these little projects were new to me, but limited in scope – the Bentley manual and a lot of head scratching were sufficient to get me through unscathed.

After doing these reliability and safety enhancements it was time to take the car down to SIR and shake it out. After a few laps the brakes were toast – Argh! I had boiled the brake fluid. I took it really easy for the rest of the day – but that's no fun!

What had I done wrong? I was suspicious of the cheap brake pads.