Sunday, October 22, 2006

Threshold

Am just returned from TWS. It was a good event for the spouse and I, as she made her debut in the "blue" intermediate group and I managed to not run off track.

TWS is a nice track for many reasons, but one of them is the tunnel. To get into the track, you have to drive through a nine foot high tunnel under the old oval. The tunnel ends in the infield.

It's a threshold between the outside world and the world of the track that is sharper and more well-defined than at any other track in Texas, save perhaps TMS. It's easy to enter the tunnel and come out the other side subtly changed. You need not worry about very much in the track world, except apexes, mid-corner speed and safety rules. It's a wonderful demarcation.

A friend carried my tires again. This part of the hobby is becoming more of a burden. I hate to impose on my mates to carry part of the car, but at the moment I have few alternatives. Within the next two years, we'll most likely buy a tow vehicle and a trailer, but for now, I have the best friends in the world.

Met a couple more Austinites at the track, and we'll sign them up for the mailing list of track folks we maintain. Always good to have more people to talk cars with.

It was a bad weekend for Corvettes. Three had catastrophic failures: Two timing chains and one head gasket. The timing chains were both on C6 Z-06 cars, leading me to wonder how good that bit of the engine is. Both cars were heavily modified, so perhaps the chain is good, unless you hop up the car. We also lost another one to some kind of oiling problem, but I don't know the details. I'm reminded more and more why I chose to leave the engine stock on my car. It ran without complaint or problem in all eight sessions this weekend.

I spent much time playing with three cars: A modified Mustang, a Subaru STI and a crazy Porsche Turbo Carerra. The mustang and the Porsche ran away from me. I was puzzled by this a bit, since normally I can catch such cars. It turned out both were making over 500 HP, the Porsche by some margin. He claimed 640 at the wheels, with his mods. I felt a little vindicated knowing that I had been outpowered rather than outdriven. The Subaru was driven by a friend, and we are about the same speed and skill level. I've got a bit more HP, the STI has AWD. Makes for fun sessions where we pass one another only when one of us makes a mistake.

Spouse's blue debut went well for the most part, though she had one spot of trouble in an early session. One change made all the difference: Not pulling off line to let other cars pass.

When I went to my first HPDE, the instructors explained how passing works: When you see someone in your mirrors that is clearly faster than you, you point to one side or the other (with your arm out the window of your car) and let them know they can pass you on that side. In the beginner classes, you do not alter your "line" or trajectory through the course, but rather just decrease speed and let the faster car get around you how they may. In the more advanced classes, you are supposed to pull off line and allow the faster car to take the fastest line. Some instructors start teaching this earlier than others, and for a relatively new student this can be misleading. Driving fast on a roadcourse is all about rythm, and when you have to interruput that every few minutes to allow a pass, you never get it, which means you slow down, and more folks want to pass, etc. Once she quit allowing that sort of pass, she did quite well and I'm very proud of her.

So I was sitting in the pit and talking about the threshold thing:
"So, it's like when you come into the track here, because of the tunnel, it's like coming into a different world. Different rules, seperate value system..." I say
"Yeah" says my friend, the one who hauled my tires "I was making breakfast in the RV this morning, and I suddenly realized, that's not a poptart, that's a pastry!"

Argh. So much for my cool metaphor. Having friends that bring you perspective is priceless, I think, in track-land or the real world.

Wednesday, October 18, 2006

Track Prep: October 21-22

Going HPDE this weekend! Woohoo! It's been too long. Prep this time was oil changes for both cars (blue and yellow; mine and spouse), plus brake pads for her. Decided on Carbotech Bobcats this time around. Hope she likes them. This plus the usual fluids check, tires, belt check, brake line check, wheel bearing check, power steering fluid check, radiator check, etc. Kind of like I imagine pre-flight to be in an aircraft, but less formal.

The track is good old TWS, in the counter clockwise direction (which is the intended route, but a little slower than colckwise).

This time out is special because my father-in-law is attending, as a driver. He was a hot rodder in his younger days, and we bought him a session. He'll be driving a Mercedes, I think, which will have plenty of power (if not cornering ability). Hope he has fun.

Tires are going to be a problem this time. My usual friendly tire transporter will not be attending, so I have to find other means of moving them to the track. This part of the hobby is getting to be a pain. I need to find a better way to take me and my tires to the track. I have thought of buying a trailer and borrowing a pickup to pull it on track weekends, but that seems silly. Might break down and put a trailer for tires on the vette, though that is a little weird (many do this, but my wife hates the idea).

I feel lucky to be solving this sort of problem, actually. A bad day at the track is still a day at the track.

The objective this time out is to run as smooth and clean as possible, and work on the chicane. The chicane at TWS leads onto the main straight (going this direction). If you hit it right, you get a great launch onto the banking and down the main straight. If you hit it wrong, your entry onto the straight is botched, and you end up slow. It's a hard left turn followed by a right and an immediate left, then a quick right that leads into a gentle left onto the straight. The last left is not really a turn, as you can use the entire width of the straight to get lined up down track, and you're pointed up the banking at that point, so there's plenty of grip.

Like most sequences, it makes the most sense to work it backwards. If you want to be pointed downtrack coming on to the straight, where must you exit that last right turn? If you want to hit that right correctly, how must you enter the upstream left? And so on. The end of the sequence is how do you brake to enter the first left. I've found that I have to hug the left side of the track before I turn into the chicane. I'm literally wheels parallel to the left side of the track, a few inches from the edge before I turn back right. That requires a very late entry into the turn, and heavy braking, as you want no slip angle when you have to turn back right. I'm really looking forward to it.

Another section to work on is the entry into turn 1 and 2, coming off the main straight. This turn can be done going very fast, but requires good spotting and good timing. I want to try a lower line and see how that works as it's a shorter distance around when you go that way.