Z3: first track day!

I finally got to drive my 1996 Z3, and at my favorite track no less! Let’s have a look at the spec sheet as it sits.

• 1.9L engine with 150k miles. It made 138 crank hp when new, so maybe 110 at the wheels right now.
• Curb weight is listed at 2600, but that’s with a spare tire and without a roll bar or driver. It probably weighs around 2800 lbs. All told, that’s over 25 lbs / hp. Not great on paper.
• 5-speed manual transmission and probably a limited slip differential (haven’t checked).
• ABS yes, but there was no stability control back on the 1996 model.
• The suspension was upgraded to KW Variant 2 by a previous owner. It’s lower and stiffer than stock. Not brutal, but also not very comfortable on bumpy roads. There’s also an upgraded ARB.
• 225/50/16 Federal Evoluzion ST-1 tires. Tire reviews show that this budget tire is not well loved.

Before heading to the track (Thunderhill West), I tried to estimate the lap time based on previous experiences in a Miata and Yaris. The Miata was often shod in 200TW and did a lot of 1:32s. That was several years ago. It weighed a lot less than the Z3 and probably made similar power. The Yaris runs 1:34s on 200TW. Here’s what I wrote in my notebook.

The Z3 on 300TW tires is not going to be very fast. Maybe 1:35. With a really sticky tire, it might get to 1:32.

The actual lap time was 1:34.001, so a little better than expected. I didn’t write down how I expected it to drive, but if I had, I probably would have written something like “typical BMW goodness”. In fact, it drove even better. I think it’s one of the best cars I’ve driven. It’s certainly not one of the fastest, but that’s not what I look for in a car anyway. You can push it hard, and it responds predictably. It has very little body roll. The rear comes around nicely under braking or throttle. Perfect. Well, except for a few things.

Not every day goes 100% according to plan. My front right brake ran really hot . When I came in after the first session, it was smoking. Almost every driver dropped by to say “when you passed me, I could smell your brakes”. I left the second session a little early and skipped the third entirely. All because my brakes were overheating. I could be sad/angry about the brakes, but I’m so pleased with the car in general that I don’t care. Not sure if the caliper needs to be rebuilt or I need a different pad compound, but I’ll definitely have to address brakes before the next track day.

Another not so great thing was the seat. I had very little support and I had to jam my left foot into the dead pedal to try to compensate. I’m would say that a seat was my next purchase, but I already have a spare, and the Z3 came with race seat mounting hardware. So it’s just a matter of me not being lazy. I may take out both seats as this is really just a track toy.

I also had plans for some lap timer testing and video, but I lost patience partly because I was so cold. Oh well, next time.