# dyno-ing your car w/o a machine?

**URL:** <https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986>\
**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:** 1\
**Showing post:** 15

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**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, 6:50am UTC](https://forums.speedlife.net/t/dyno-ing-your-car-w-o-a-machine/44986/15 "2008-03-14T06:50:42Z")

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you forgot to include rolling resistance of the tires, probably have to take into account the air density to get a more accurate F resulting from air… shit if you actually know what you are doing in regards to this, but I doubt many people would want to actually sit down and do the math to this, and you might want a program like mathcad where you only have to define the variables.

EDIT: and you have to also take into account your lack of reaction times for the timing system

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