Dynamometer Results & Comparisons - has anyone ever thought or made a portable 1/4 mile track?
03-24-2012, 09:59 PM
i have been thinking of making a 1/4 mile setup with a christmas tree. some relay timers and two trigger for 60 foot and 1/4 mile time. and then a trap speed on top of that.
so when the light goes green it starts to count and traps the speed. then when you hit the 60 ft the first timer stops then when you hit the 1/4 mile the secound timer stops.
03-24-2012, 11:40 PM
The program logic to set one up isn't really hard, but I don't know how accurate or feasible it would be. A lot of physics classes use software called Vernier to data log lab experiments with velocity and such. I had to use it in class to record speeds of falling objects and stuff like that.
I'm sure drag strips use a similar setup (with better sensors/equipment/software) to track runs.
As far as setting up a portable 1/4 mile with something like that, I'm sure it could probably be done, but I can't exactly see it being cheap (1/4 mile of cable for sensors?). I don't see it being feasible unless you have a half mile of straight unused road somewhere. It also wouldn't be as controlled since strips do track prep and stuff.
Still good food for thought though.
P.S. At the rate smartphones and apps are going, I wouldn't be surprised to see a gps based app or something similar in the near future to record 1/4 mile runs.
03-24-2012, 11:59 PM
the only reason for asking is the closest drag strip is a couple hours away and i have alot of straite roads that no one drives on. and i know it wont be the cheapest with the wires. i talked to my old man today about it ( he is a enginear)and the only issue we can come up with is how long it will take to get the singles from the sensors to the controller and if you put the christmas tree and timer 1/8 mile down the track it will take less wire (cheaper) but im going to talk more with him about it and see what we can come up with.
and i know the road wont be prepped but my car lunches hard on the street.
i never been to the drag strip ever in my car.
just food for thought ( kinda out there:eek2:)
03-25-2012, 12:38 AM
Unless your timers are spot on and your 1/4 is perfect length, there is an app on iPhones that are within a few tenths of a second...
03-25-2012, 10:49 AM
If it's something you can't find on google, you could always try getting in touch with track owners to see if they'll reveal what they use to overcome the same signal distance problem.
03-26-2012, 12:30 PM
just get a vbox
03-26-2012, 06:54 PM
I have a Port-A-Tree timing system that is exactly what you are after. look em up.
I use it to tune my Drag snowmobiles for grass, and ice
yes the sensors have to be in EXACTLY the right position
03-27-2012, 10:34 PM
there are several Chassis dyno's that have a 1/4 drag test...
I know my buddies mustang dyno can do it, and he has had a dyno day drag race day with it...
his car did a 10.6x on the dyno launching off the trans brake and at the track he pulled a 10.3x
he spun the tires slightly on the dyno...no burnout heat to make them all sticky..LOL
03-28-2012, 09:22 AM
Vbox is about $2k minimum, you could get a high refresh gps receiver and datalog it on a pc or phone and get accurate readings that way
This one is only $80 and records at 10hz http://www.qstarz.com/Products/GPS%20Products/BT-Q818XT-F.htm Even has performance software, not sure how good it is for 1/4 mile but would be easy to figure it out yourself.
03-28-2012, 10:14 PM
the full video vbox with cameras and shit is that expensive. i believe they have a vbox a 10hz one that sticks on your windshield for around 400 bucks. records 0-60 0-100 1/4 mile 60-130 blah blah. atleast i think its still named vbox in that version.
this is the one. its 499 but records tons of shit. even lap times if you road race or whatever
03-31-2012, 05:05 PM
I got one of the $80 Qstarz receivers off Amazon and drove around with it in my car and it works really well, you can measure whatever you want down to 1/10th of a second since it is logging at 10hz, I use my laptop. I wrote a program to show speed at each log point so you can tell 0-60 or whatever, I just ran 12.1 0-60 in my diesel Jetta :shiner: Im going to take it to the dragstrip next weekend and leave it on the whole time and see how accurate it is, should be dead on since it is gps and 10hz. Will be interesting to see how close the 60' is.
04-06-2012, 08:03 PM
I ran a pass at Island with the gps logger running, all the stats were under 1/10th of a second on the time slip, 60', 330, 660, 1000, 1320 were all dead on. MPH were also right. Pretty nice you can have a dead on timer for $80. 0-60 showed 3.3 seconds even with a terrible 1.9 60'.