SteveR Posted May 23, 2005 Share Posted May 23, 2005 I'm having a go at making my own integrated timing & lighting software/hardware to run & control a drag race set-up. (The idea is that this will be available for the club to use, and I might even develop it into a sideline commercial project if all goes well). I am ging to need some bits of advice as I go along though, so will post here as and when questions pop up, like now.... here comes question #1.... Quote Link to comment Share on other sites More sharing options...
SteveR Posted May 23, 2005 Author Share Posted May 23, 2005 Question 1) I am looking at using light/laser beams that are broken to indicate a car is in the right/wrong location (pre staged, staged, left start line marker early/measure reaction times, to measure & calculate the terminal speed and finally to see when the car has crossed the finish line) BUT need to know how far apart the emmittor and sensor should be. Technically speaking the closer they are to each other the better - as they get further apart you need more expensive and powerful and selective equipment and it gets harder to set this equipment up (aliging lasers that you can't see for example), and off the top of my head the price is likely to increase in proportion to the square of the distance - so keeping the distance to a safe minimum is key here. I figured that 2~2.5metres apart would be ok for the start line stuff, but that might be pushing it for the closing bits (terminal speed and finish line) - even in crystal clear vis aiming for a 2.5m gap at 100mph isn't too clever??? What is the educated/experienced opinion of what would be a good safe minimum gap (for start and end lines). TIA, Steve Quote Link to comment Share on other sites More sharing options...
tbourner Posted May 23, 2005 Share Posted May 23, 2005 Love your signature!!! Oh sorry.... erm.... I reckon if you could set up the 1/4 on a strip that had a white line painted on it, you could reduce the width of the finish line as the white line down the centre would act as a subconscious guide to follow!!! Or would it confuse you and make you steer in funny directions!! Quote Link to comment Share on other sites More sharing options...
SteveR Posted May 23, 2005 Author Share Posted May 23, 2005 For background info: I did look at pressure sensors - not suitable as I think the cars will have reduced traction off the line and won't appreciate hitting a small bump at the 100+mph end line - or - more likely, just fling the sensors out of the way as they burn away. Hence I'm trying to come up with a solution that has abosultely NO physical interaction between car & timing gear at all. I also looked at magnetic prioximity sensors too, not suitible as they won't be entirely dependable/accurate (they will vary depending on each cars' individual magnetic signature - which will vary from car to car providing innacurate results and unfair advantages/disadvantages) and might not pick up a car passing at high speed - so no results at all. Quote Link to comment Share on other sites More sharing options...
SteveR Posted May 23, 2005 Author Share Posted May 23, 2005 Love your signature!!! Thanks, I can't stand veg, me. I get fed up with people saying it's good for you so I thought I'd manipulate a statistic in my favour Oh sorry.... erm.... I reckon if you could set up the 1/4 on a strip that had a white line painted on it, you could reduce the width of the finish line as the white line down the centre would act as a subconscious guide to follow!!! Or would it confuse you and make you steer in funny directions!! I thought about the white line thing - maybe even a temporary chalk line(s) towards the finish line. I'm not sure how this would work for hired airstrips/tracks/similar though - i.e. would be be allowed to do this? Cones would be another option, if they could be gauranteed not to move if a gust of wind comes along, but still - is a 2.5m gap going to be enough at 100~130mph? Quote Link to comment Share on other sites More sharing options...
SteveR Posted May 23, 2005 Author Share Posted May 23, 2005 Question 2: Reaction times - I've read on an American site that this is from the first amber light switching on, to the car moving from the line. They say that most classes have the first set of ambers on for 0.250s, then the second set of 0.250s, meaning that the green lights go on at 0.500seconds, and therefore any reaction time of 0.500 is thus perfect (anything less is a foul/whatever that's called - red light anyway! ). Is this correct? - surely it would be better to time from when the green light comes on??? (although, thinking about it, that wouldn't tell you by how far you have jumped the gun, if you did). Ta, Steve Quote Link to comment Share on other sites More sharing options...
SteveR Posted May 23, 2005 Author Share Posted May 23, 2005 come on guys, having never drag-raced myself I need your answers! Quote Link to comment Share on other sites More sharing options...
SteveR Posted May 25, 2005 Author Share Posted May 25, 2005 I feel like the chicken in that kids book, the one that wants help cooking bread... well, when you all want drag timing/top speed measuring don't expect to just come running to me Quote Link to comment Share on other sites More sharing options...
terribleturner Posted May 25, 2005 Share Posted May 25, 2005 Come on guys, we really need this info. Are you all saying that none of you know this info?? Anybody know hoe wide each lane at Santa Pod, or York race way is?? Quote Link to comment Share on other sites More sharing options...
terribleturner Posted May 25, 2005 Share Posted May 25, 2005 Steve, probably doesn't help but i found this Word Doc. Not alot of useful info, but found the following snippets. Starting system will use the 3 amber Pro Start. All amber lights are activated (shown) with a 4 tenths of a second delay to the green light start signal. Length of Track: ¼ mile Length of Shutdown area: ½ mile Width of Track: 66 feet More stuff...... Starting the race: After both race cars are staged, the "Christmas Tree" is activated and three amber lights and one green are sequenced. Drivers use amber lights as a guide to gauge when the green light is coming on. Leaving the startline too soon and a the bright red "foul" light shows. End of race for a red light. Quote Link to comment Share on other sites More sharing options...
SteveR Posted May 25, 2005 Author Share Posted May 25, 2005 Thanks James I could guess at how wide Santa Pod is, but the problem would be making the beam sensors work over that distance - reliably - and not cost £££s. If anyone could tell us a sensible minimum that would be a good starting place. If not i'll just go out in my Orion at the weekend, place a couple of cones 2.5m apart, take a mile run-up and see what happens! Quote Link to comment Share on other sites More sharing options...
SteveR Posted May 25, 2005 Author Share Posted May 25, 2005 Must have been typing my message before I spotted your 2nd one - that doc & clippets are useful thanks. I've been scouring the internet for rule s7 regs & variables - basically so I can cutomise everything on the fly; dial-in (head-start), timings between the different lights going on & off, the distances it can be used over, the purpose (drag timing/top speed measure/mix of both/lap timing _may_ be possible - can you think of anythign else?), blah blah blah - all configurable! I'm just wondering what gap people could comfortably get through at 130mph+ - maybe even 200mph :o Quote Link to comment Share on other sites More sharing options...
carl0s Posted May 26, 2005 Share Posted May 26, 2005 I'm just wondering what gap people could comfortably get through at 130mph+ - maybe even 200mph :o well unless you want kit in the middle of the road, it's going to have to leave ample space for two lanes and two cars so a side-by-side race can go through isn't it? Quote Link to comment Share on other sites More sharing options...
colsoop Posted May 26, 2005 Share Posted May 26, 2005 Has some info Here Dont know how useful it will be: Quote Link to comment Share on other sites More sharing options...
SteveR Posted May 26, 2005 Author Share Posted May 26, 2005 well unless you want kit in the middle of the road, it's going to have to leave ample space for two lanes and two cars so a side-by-side race can go through isn't it? Each lane will need it's own timing gear, so I need to work out what is a comfortable space for 1 car to get through at speed. I should have made that clearer, sorry! Quote Link to comment Share on other sites More sharing options...
SteveR Posted May 26, 2005 Author Share Posted May 26, 2005 Has some info Here Dont know how useful it will be: The more info the better, hadn't spotted that site, ta Quote Link to comment Share on other sites More sharing options...
colsoop Posted May 26, 2005 Share Posted May 26, 2005 In terms of size between cones i would go for twice the width of the supra. (181 cm ) You are going to get a mix of experienced and inexperienced drivers running so need to allow for that. Just a thought. Quote Link to comment Share on other sites More sharing options...
lust2luv Posted May 26, 2005 Share Posted May 26, 2005 Is this any use... Christmas Trees Tells you exact position of the infrared beams on the start line and the two different variants of tree. Quote Link to comment Share on other sites More sharing options...
SteveR Posted May 26, 2005 Author Share Posted May 26, 2005 brilliant, thanks a lot guys! Twice the width of the Supra - good plan (hope it's achieveable, it _should_ be), and 2 types of tree - spot on! Thanks!! Quote Link to comment Share on other sites More sharing options...
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