# dyno-ing your car w/o a machine? **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [March 13, 2008, 6:18pm UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986 "2008-03-13T18:18:10Z")\ **Posts on this page:** 14\ **Page:** 2
**Author:** ![ultradriver10000](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ultradriver10000/32/7397_2.png) [@ultradriver10000](https://forums.speedlife.net/u/ultradriver10000)\ **Post date:** [March 14, 2008, 9:36am UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/21 "2008-03-14T09:36:22Z")
You can find an average of the negative forces by decelerating. Take your car up to say 100mph, then at a set point let off the gas and let it cost to a stop. Time it, and take the distance it took you to stop. That will give you the average force needed to overcome to get to 100 mph approx. F=MA Mass= your car Acceleration will be the Distance/Time This force will include your rolling friction, air friction etc. It will not incluse power train loss. ---
**Author:** ![Fry](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fry/32/7284_2.png) [@Fry](https://forums.speedlife.net/u/Fry)\ **Post date:** [March 14, 2008, 9:42am UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/22 "2008-03-14T09:42:58Z")
> [@ultradriver10000](#): > > You can find an average of the negative forces by decelerating. Take your car up to say 100mph, then at a set point let off the gas and let it cost to a stop. Time it, and take the distance it took you to stop. That will give you the average force needed to overcome to get to 100 mph approx. > > F=MA > Mass= your car > Acceleration will be the Distance/Time > > This force will include your rolling friction, air friction etc. > > It will not incluse power train loss. There’s an interesting idea. Acceleration is usually delta-v over delta-t, but other than that little brainfart I like it. ---
**Author:** ![ultradriver10000](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ultradriver10000/32/7397_2.png) [@ultradriver10000](https://forums.speedlife.net/u/ultradriver10000)\ **Post date:** [March 14, 2008, 9:52am UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/23 "2008-03-14T09:52:06Z")
> [@Fry](#): > > There’s an interesting idea. Acceleration is usually delta-v over delta-t, but other than that little brainfart I like it. Your correct, my distance and time was meant to be the change in distance / the change in time. The distance being from the point of let off to the spot of actual stoppage. The time would be from the same two points. ---
**Author:** ![neonglh](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/neonglh/32/4951_2.png) [@neonglh](https://forums.speedlife.net/u/neonglh)\ **Post date:** [March 14, 2008, 11:52am UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/24 "2008-03-14T11:52:38Z")
> [@Viper966](#): > > or buy a used Gtech for less then 30 bux and VOILA My balls can give better dyno numbers than a gtech ---
**Author:** ![Fry](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fry/32/7284_2.png) [@Fry](https://forums.speedlife.net/u/Fry)\ **Post date:** [March 14, 2008, 12:31pm UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/25 "2008-03-14T12:31:51Z")
> [@ultradriver10000](#): > > Your correct, my distance and time was meant to be the change in distance / the change in time. Which still gives you velocity, not acceleration. 😉 ---
**Author:** ![66impalass](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/66impalass/32/7429_2.png) [@66impalass](https://forums.speedlife.net/u/66impalass)\ **Post date:** [March 14, 2008, 1:04pm UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/26 "2008-03-14T13:04:03Z")
acceleration is the change in distance over the change in time square. ---
**Author:** ![walter](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/walter/32/7202_2.png) [@walter](https://forums.speedlife.net/u/walter)\ **Post date:** [March 14, 2008, 2:49pm UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/27 "2008-03-14T14:49:29Z")
this thread is heavy with :picard: ---
**Author:** ![squid](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/squid/32/4984_2.png) [@squid](https://forums.speedlife.net/u/squid)\ **Post date:** [March 14, 2008, 3:18pm UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/28 "2008-03-14T15:18:54Z")
Why not 4wd at Kennedy’s? ---
**Author:** ![snowracer101](https://avatars.discourse-cdn.com/v4/letter/s/258eb7/32.png) [@snowracer101](https://forums.speedlife.net/u/snowracer101)\ **Post date:** [March 14, 2008, 3:39pm UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/29 "2008-03-14T15:39:44Z")
Guys, I’m not looking to actually do it… I was just wondering what the link to the site was…I thought it was much simpler. ---
**Author:** ![squid](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/squid/32/4984_2.png) [@squid](https://forums.speedlife.net/u/squid)\ **Post date:** [March 14, 2008, 3:40pm UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/30 "2008-03-14T15:40:38Z")
Not even dying is simple any more. ---
**Author:** ![RedGoober4Life](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/redgoober4life/32/7610_2.png) [@RedGoober4Life](https://forums.speedlife.net/u/RedGoober4Life)\ **Post date:** [March 14, 2008, 8:13pm UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/31 "2008-03-14T20:13:10Z")
> [@Fry](#): > > Only taking into account acceleration and drag: > > F=m((v2-v1)/t) + .5_rho_v^2_A_Cd > > Good luck getting any sort of accuracy out of it. > > Well, that just gives you average force and at this point I’ve lost interest. I prefer the time-dependent Schrodinger. ---
**Author:** ![ultradriver10000](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ultradriver10000/32/7397_2.png) [@ultradriver10000](https://forums.speedlife.net/u/ultradriver10000)\ **Post date:** [March 15, 2008, 7:20am UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/32 "2008-03-15T07:20:59Z")
yah square the time my bad ---
**Author:** ![355firebird](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/355firebird/32/7369_2.png) [@355firebird](https://forums.speedlife.net/u/355firebird)\ **Post date:** [March 19, 2008, 3:13pm UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/33 "2008-03-19T15:13:37Z")
just get a time slip ---
**Author:** ![Carnut](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/carnut/32/7590_2.png) [@Carnut](https://forums.speedlife.net/u/Carnut)\ **Post date:** [March 19, 2008, 4:01pm UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/34 "2008-03-19T16:01:30Z")
> [@Viper966](#): > > or buy a used Gtech for less then 30 bux and VOILA exactly [Previous page](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986.md?page=1)