[jimclark]

Having now watched a fair number of autocross videos of various sorts, and scrolling through performance times of several events, I think I understand the method (generally speaking) and the means by which times are generated, but I'm not sure.

For almost every event of which I've watched video, the driver begins his run upon the hand (and verbal?) signal of a race official. The driver dashes through the course and crosses a finish area which has an electronic timing device aimed along/over the finish line so as to register finish time.

Is there also a "start time" electronic eye sort of apparatus that registers start time? I presume so, but often can't see it in the vids.

What standards are expected of the mechanical framework and the officials that place and keep stable the timing elements? Times are generally registered in thousandths of seconds; at that level, even a slight nudge of the apparatus can affect time registered, I'd guess.

What is the expected level of reproducibility of results? Are there other standards expected of timing of these events? Any special considerations one must undertake to do it properly?

 

[Cligedy]

Most clubs use an optical trigger for their start and finish lines. Timing starts when the driver crosses the start line, not when the driver is given the Ok to begin. The starting line is usually 20-50 feet after the start worker, so that hard launches aren't usually necessary.

The optical triggers send their signals to a computer which uses software to account for multiple drivers, so that more than 1 car can be on course at a time and still generate representative times.

The timing lights can be costly and are set up in small enclosures on the ground. If you want to piss off a lot of people, drive like an out of control ass and run over the finish lights. No sense of humor about that at all.

 

[RodMoe]

During the drivers meetings we are told don't hit the timing equipment if you do and break it you pay for it. Plus the drivers all give you crap .. Lol

 

[Slowclimb]

Even a course worker running through the lights generates hostility as it results in a bunch of reruns - reruns result in less regular runs for everyone...we don't get threatened with paying for them, they they are never happy when someone takes them out.

 

[jimclark]

Looks like my supposition holds true--it's all optical sensors that trigger on/off, and any mucking around with 'em will cause grief, anxiety, and heartache. And anger, no doubt. Probably lots of anger.

 

[Smokin]

We'll school you in a couple of weeks. You are registered for event 1 aren't you? That will get your hand-foot-eye coordination scaling up... ;-)

 

[jimclark]

Smokin--I'm probably gonna be out of town that weekend--family. But I say "probably" because it turns out it may not be so. If that's the case, well, I hope to be there!

 

[Smokin]

We'll see you at the school the next week anyway. looking forward to it............

Club meeting next Tuesday!

 

[jimclark]

I'll make it to the meeting; busy weekend ahead. See ya Tuesday!