Mmagus wrote:As to the finish...last month I beg to differ. For the safety of the timing equipment we try to finish on a straight, and there was a lot of run off space.
Finishing on a straight is a fine idea to protect the timing equipment, but the length of that straight and the possible speed through the final turn before the finishing straight is critical. They must be gauged to the capabilities of the fastest cars (with the least experienced drivers) running. Last month, my student had an RX-7 Mazda with an LS6 SBC V-8 in it (430HP in a 2300 lb. car on street tires w/ marginal brakes). The torque of that car allowed him such a squirt of speed out of the last turn to the finish line that he could not easily slow down enough before the right turn back to the grid. I finally told him that he would probably have to lift before the finish line in order to stay on the course after the finish and not DNF or hit cones. I almost went off myself the first time I went through the lights at speed and did not immediately threshold brake to "whoa up" enough, and then still had to trail brake through the turn to make it, so I don't agree that last month's course was a whole lot better. It didn't have any K-rail behind it though, just much softer spectators.
This month we struggled with the finish, I admit, we changed the finish three times from the first drawn design, though to my knowledge we only had one car out of 111 DNF after finish.
You must mean in timed runs only one car DNF'd? I was parked down by the finish, and all day in practice cars without ABS were locking brakes after the finish and running down and through the cones on the outside of the left turn leading to the grid. For several practice sessions, no one even picked up the downed cones there as they were hit so often. I agree that there was probably enough runoff after the cones to prevent anyone from hitting the K-rail unless they had total brake failure or brain fade (which can't really be planned for in any case). But even with my little 180HP/2300lb. car I was still trail braking to make it around that turn, even after threshold braking immediately after the finish. IMHO, the final turn was just too fast. Either the radius of that turn needed to be reduced to lower entry and cornering speed, or the timing lights needed to be moved up the course 15 or 20' to reduce the acceleration distance after the exit and before the finish, which would have also increased the straight-line braking zone. With lower cornering speed in the final corner, you don't need as much distance to the timing lights to protect them from a car that spins there, as they won't slide as far because they are going slower when they lose control. That last turn should probably be the slowest one on the course, just to "whoa" drivers up before the finish naturally, and save the threshold braking for the long straightaways instead of after the lights.
Lastly, I say this to all you good forum folks, not in a defensive manner, but so that we are as safe and fun as possible. I send the track to Safety, the CDI Team, and the other AX Guru's before posting it. Then we try to get it posted early for preview, this month was a bit tight. I recieved 0, Zero, None, nada, ziltch, comments on possible issues with the design. If you see something that raises a flag in your minds, Please, please, please, let me know. Change before throwing the track is fairly simple, but gets much more complicated the day of the event, especially if we have to throw the track on Saturday morning.
My intentions in offering these comments are only meant to be positive and helpful. The last thing I want to do is make you defensive about the great job you are doing for the club, or to dampen your considerable and commendable enthusiasm for designing and managing fun courses and events for us to run, in what is undeniably a deteriorating venue. Your contributions are greatly appreciated. I would suggest, though, that it is difficult if not impossible to make such comments or suggestions before the track is thrown. The only way to gauge the "finer" safety parameters of a track is to drive it at speed. Judging things from a map or drawing can tell you basic things like distances to fixed obstacles, etc., but it is very difficult to tell ahead of actually driving the course with some race pace what the dynamics will be. This is normally only done by the safety chairs right before the event starts, and it is really their responsibility to bring these issues to light. By the time an ordinary competitor like me gets to try the course at speed and make suggestions, it is past the time when you can easily make changes. A tried and true strategy for avoiding these kinds of issues is to put a fairly "kinky" turn right before the finish, and also shortly after the start (so drivers are not tempted to be speed-shifting through second and third gears before entering the first brake zone at 50mph with cold pads). We seem to be trending away from this past practice.
Speaking of changes, when there is a major adjustment of the course done to avoid surface break-up, etc., which seems to be getting more and more common, are we still doing a thorough job of informing folks about it? This should include a PA announcement as well as a warning by the starter to each driver after the change is made. I am just mentioning this because I did not hear anything about the change to the downhill "S" turns before I arrived there the first time, and was a little surprised to find that what had been a couple of third-gear sweepers were turned into a second-gear chicane!
I realize we get a warm-up lap before our timed runs and can do it at "reconnaissance" speeds, but I tend to push a little harder on that lap to get tire and brake temps up before the first timed run (without hitting any cones. hopefully!) Maybe I missed the PA announcement when I was warming my car up for the session? This is why a followup warning from the starter is always helpful.
Thanks for all you do for the club, Mark! (and your fantastic attitude about being the AX Whippingboy)
TT
Posted: Sat May 07, 2011 7:23 pm
It also seemed that after a full day with not many spins, many folks felt that the could magicly just get faster and still hold those lines in Timed runs and it was a spin fest. lol I know that all set us behind on time but you were all very patient and flexible and I thank you for it. I hope everyone had fun.
). Great job Mark in soldiering on through a day with a few hiccups and making it happen.