Archive for the 'driving' Category

HOD @ Laguna

I spent the day at Laguna Seca with Hooked on Driving yesterday. This was my first event with HOD, and my second day at Laguna with the new race car. Some observations:

- Shaved 5 seconds. Finished the first session about where I was at my last visit, in June. Technically speaking, in June, I was RFS — really fockin’ slow. Five seconds sounds like a lot, but there’s 2-3 easy seconds still available. There’s more after that, but will be harder to harvest.

- In T6 I improved about 5 mph, and I still need to refine the line. There’s another 5 mph if I can consistently nail the right line. (T6 at Laguna has one totally excellent line, and any other line is crap.)

- I could be faster in 5,6,8a,9,10 & 11.

- With a camcorder that shoots glorious 16:9 HD, with a wide angle lens, and with 60 progressive frames a second (the way sports video should be), the “happy hands” are real easy to see. Was that a hitch, or a twitch or a saw? Why yes it was. How about all three? Maybe I can cut it down to 4:3 before posting.

- Widest range of cars I’ve ever run with. An E36 can get a little bit of tow through T1 off a Lotus 7. A tow off a Lancer is better. SRF’s are hard to see from a (relatively speaking) ginormous production car.

- Used the HANS for the first time. My upper traps hurt. Was I doing it wrong? Just need to get used to it? Should I go for the ultra padding? Getting in and situated takes more time. Getting out is harder, and slower. I now have ample motivation to do the NASCAR door bar, for sure. Fast egress is a good thing. The driver could use some modification also. Ahem.

- Based on this one day, HOD puts on a good event.

ur doin it rong


The Circuit Compilation

Thunderhill Links

Official Site
- pdf map at official site

Trackpedia

GGR PCA turn-by-turn

NorCal SAAC turn-by-turn

cobwebby page at NA Tracks — features a topo map

gofastvideo.com

BMW Club Racing School

(more to come)

Buttonwillow

I ran Buttonwillow with the San Diego Chapter of the BMW CCA. A few observations:

- The car is very quick. I started the weekend very slow, worked on smoothing out my inputs, worked on getting re-familiarized with the track, and gradually built speed. By Sunday afternoon I was putting together some very nice laps. There are some fast portions of the track that the car certainly can take much faster. I’m not there yet, but with enough seat time …

- The car is very balanced. With the current suspension set-up, the car never felt out of sorts. I got a little greedy cresting the rise at Cotton Corners, and got a touch of power oversteer, but with some feathering, it came right back. I took a variety of lines through the Offramp, and couldn’t find one that the car didn’t like. I experimented with different lines through Talladega, including some passes on the inside, and it was all good.

- Racing starts are very cool. One of the run groups was a BMW CCA Club Racing group. While watching the start of the first race on Saturday, I felt that old, familiar adrenaline rush. I’ve decided to upgrade my August school at Thunderhill to the club racing school group.

A Lap of RFR

Here are two versions of one of my laps at RFR.

The first is basically the camera output. In FCP, I set the in and out points, and did an “Export Quicktime Movie” operation, which avoids re-encoding. I assume FCP re-encodes GOPs at the in and out points as necessary.

It’s a 200+ MB file. On my fairly decent lap top (dual core 2 GHz with 2 GB memory) Quicktime 7.4 can’t keep up, and ran at about 20-30 frames/sec (out of 60 frames/sec). On a similar computer (with upgraded graphics capabilities), Quicktime ran about 40 frames/sec, Main Concept’s H.264 plugin for WMP had syntax problems, and the VLC Media Player was near flawless at 40% CPU utilization.

The camera file was 12 Mbps. The output of FCP is slightly above 14 Mbps. I’m not sure what the overhead is. Recoding the head and tail GOPs can’t account for that magnitude of difference.

1280×720 16:9 59.94 frames/sec 12 Mbps H.264 from Sanyo HD1000 with in/out points edited in Final Cut Pro 2

The second file is quarter HD resolution, with 4 Mbps set as the cap for the H.264 codec. To generate this, I used “Export Using Quicktime Conversion”. Again, FCP has some overhead above the set bit rate, yielding a 4.2 Mbps final rate. The Quicktime player should be able to keep up with this file on most current machines. The file is 82 MB, so download may take a few minutes … or so.

640×360 16:9 59.94 frames/sec 4 Mbps H.264 from Final Cut Pro 2, transcoded from source above

Here’s a quick critique of my driving in this footage:

The Esses: There’s 5 to 10 mph more there. I wasn’t satisfied with the consistency of my line, so I wasn’t ready to find that extra speed. You can just brush the first two curbs (1, 1A). Riding them does bad things, especially when you drop off the end of the second curb into a hole.

Turn 3: Need to go faster, and then it’s possible to keep one position on the wheel and throttle steer from 2 to the entrance of 4.

Sunset Straight into 12: Rather than grabbing forth, I just backed off and waited for the braking zone. I need to practice heel-toe in that car if I’m going to do lots of shifting. For now, I kept the shifts to a minimum just to focus on line. (The synchros are pretty worn, so you really need to do a double clutch heel-toe.) Also, this particular braking zone is so wavy, there’s no sense diving in hard. Esp. with a stiff suspension, it’s hard to keep the tires on the ground, so a long, gradual braking is called for.

Turn 13: I played with two lines. This is the “go deep and rotate hard” line. There’s a “just left of middle until turning down for the apex” line that is worse geometry but makes use of better available grip on the surface. The latter line is more of a racing line. Not sure which is a faster qualifying line. (telemetry, telemetry, telemetry).

Turn 15: Same gearing comment as Sunset.

Turn 15A: There’s more grip available than I’m using.

Horse Shoe: Again, more grip available than I’m using. There are a couple lines I played with. “Ride the rim, then dive to apex”, and “double apex with a diamond”. This lap has a line kinda in between. Pick one, dude! The double apex made some instructors nervous, because it’s not the “school line”, and I could have easily taken the line from a couple guys (and have been sent home). Not sure which is the better qual line because I don’t really know how many g’s I can pull at the turn in, other than “a lot more than I did on that lap”.

Turn 23: Not a bad line that lap. Struggled with this corner. It’s a much faster corner than I took it, but, like the Esses, I was holding back until I got precision and consistency. It’s kinda like 6 at Laguna in that there’s a real sweet spot. The sweet spot isn’t as narrow as Laguna’s 6, but still, you want to be sure you can nail it before trying to push the limit.