Spec Miata trackday 6 July 2004
It's been almost a week, and I should have written this up much sooner, but I've had lots of life happening to me lately.
Last week, on 6 July, Dave Vodden put on a Spec Miata day at Thunderhill. It was a last minute event, organized on a rather ad hoc basis. My impression is that someone cancelled, and Dave saw an opportunity to make use of the open day.
About 6 spec miata drivers showed up for the day. If your goal was track time on an open track, it's hard to get a better deal. I was slow getting out on track to start (about half an hour after the track went green, maybe more), and I took a very long break in the morning session, to rest up and rehydrate, and I still put 101 miles on the car before lunch.
If anything the afternoon session was even moreso, as two or three drivers had left by 2PM. So, there were three or four people sharing the track at the end of the day.
Those were the best bits, lots of tracktime, with an average of 3-4 cars on a three mile track at any given time during the day.
Dave didn't plan out any specific instruction, or exercises. I completely understand this, and I'm not denigrating him in any way for the way he ran it. For an event, put on at such a last minute, he did a great job.
He talked a bit with folks before the morning session, discussed hand signals for lead and follow, encouraged the faster, or more experienced drivers to lead around the less experienced, and went out on the track to be a roving instructor.
At lunch, we discussed what we did in various turns, and what we should do. We talked about gear choices, lines, and shared our techniques for each turn.
I found out, that by verbal description, it seems that I'm doing just about the same as Dave in just about every turn. Unfortunately, my laptimes are still 4-5 seconds a lap slower than his.
One of my biggest motivations for heading up there for that day was to be able to follow faster drivers and learn from them. In the morning session, Bill and Dave were having quite a dice. I was pretty much able to keep up with them, until I spun in turn 6 after a few laps. However, the offensive and defensive lines they were taking, were not the fast lines, and I didn't really get a chance to do much more than practice keeping up and trying a few variations through several of the turns.
In the afternoon, I thought I had caught up to Dave, right after he'd been leading a slower driver around. I chased him down for a lap or two, but when he pulled into the paddock, low on fuel, I found out that it wasn't Dave that I'd been keeping up with, but one of the track employees Dave had loaned his car to.
My day ended early when, as I now know, my car sucked a valve and customized #4 piston to have very low aerodynamic drag, by the expedient of a big hole in the middle of the piston.
Larry Oka, very generously, let me take one of his cars out for a few laps when I asked about renting one of his cars for 20 minutes so I could see if my poor laptimes were due to the car, or my driving.
If the speedometer in the car I borrowed lied the same as the speedometer in my car, it had substantially better acceleration. Not being at all familar with the feel of the car, as well as REALLY not wanting to prang a borrowed car in the three laps I had it, I was being very conservative through the turns, but was hitting much higher speeds at the end of the straights 105+ versus 95-100 at the end of the main straight, and similar differences going into turn 9.
I also learned that I really need to install my hotlap in the car. The transponders are great, but they don't give the instant feedback that lets me know whether what I'm doing is really faster or slower.
Another thing I learned was that trying to take turn 9 at Thunderhill by keeping the gas flat and just left foot braking a bit, does not work. I haven't gone through the video to watch that agricultural excursion yet, but judging by the dirt I scattered all over and in the car, it should be rather entertaining to watch.
Checking my speedometer, coming out of turn 2, I did determine that third gear gave me a touch faster exit speed, usually about 82MPH rather than 80MPH in fourth.
Speaking of video, I taped almost all of my on track sessions, so if you were there and want video of while I was behind you, let me know, I'll try to burn a CD for you.
I would really love to do another one of these days. I'd actually prefer to have more drivers there. Perhaps one could bribe some of the front of the pack hotshoes, to come out and teach, by letting them do the day for free. Do a morning session of about an hour, with transponders on, and instructors observing, from either on the track or watching from a turn. Group 2-4 students with each instructor, based on laptimes. I know that if I have more than one student and they aren't running close to the same laptimes, it's very hard to do a good job helping both of them.
I'd also love the opportunity to do one of these days doing "exercises" rather than just turning laps. Practicing specific skills. I just don't know what those exercises would be. On the raceteachers yahoo group, someone mentioned driving a session with people paired up side by side, all the way around the track, as fast as they safely can. Stuff like that.
I suspect that the day could be more of a financial success if it were run with two groups, which alternated 25-45 minute sessions. One group being Spec Miatas, the other being "street" Miatas, where the drivers have open passing experience. Everybody would still get three hours of tracktime, but the potential market would be a lot bigger.
Despite it not being quite everything I'd hoped for, the day was a lot of fun. Even though my afternoon times were a touch slower than my moring times (105F rather than "only" 95F in the morning, my motor being about to explode, me being hot, tired and thirsty?) I did learn a lot during the day. My lines through and exit speeds on turns 1, 9 and 10 improved tremendously. I had a lot of fun and got an insane amount of track time (180 miles when my engine blew 40 minutes before the end of the day).
click on thumbs for a bigger picture. We didn't get a good picture of the valve head sitting in the hole in the piston.
small size movie of engine destruction
movie of engine destruction
what I found
How long to pull a motor?
Clickable thumbnails at:
just a few of just the piston
32 more of the damage:
Sandy sent me the files from the transponder for the day:
The fields in the database are:
5 and 6 disregard
7. lap time in seconds
8. transponder #.
Your important fields are 2, 4 and 7.