Thread: Calculating horse power

With your calculation the car wouldn't develop any horsepowers going on a flat road, right?

Originally Posted by djmickyg

i had a thought last night..
calculating horse power with gps...

i know im going to get flamed for this, so go on an get it all out of youeself if u feel the need to

and i know it will be pretty unacurate...

but here goes...

i did a bit of a search to refresh my menmory on calculating horse power
this is what i came up with

http://wiki.ehow.com/Calculate-Your-...nd-Horse-Power
http://www.glenbrook.k12.il.us/gbssc...rgy/u5l1e.html

so going with the first site..



we know the nmea refreshes every 1 sec.. so t = 1

mass would have to be entered in some ini file somewhere. this is one of the measurment that could make it in acurate

height would be the current altitude measurment - the altitude fromt he previous second. giving the rise over that one second

well this is just a start.

comments?

Good one.

Also, from that first web site:

"Don't take the numbers too seriously; they can be inaccurate under certain circumstances. For example, air friction is not part of the calculation and lower numbers can occur if the stairs is not very steep (side movement does not count). So they should not be considered as numbers that say how strong you are, just how efficient you are in that particular stair."

Wind resistance, or drag, matters when talking about an automobile.

Here's a different way to accomplish what you are asking for: Using OBDII as a dyno.

you would'nt use altitude, thats just for the example, you'd use distance of course.

and it would only show teh current amount of BHP you car is producing at that moment in time.

It would be 10x better off your speedo.

Another good way to calculate HP is to rig a bicycle to a small generator or alternator and measure the voltage drop and currect across a load. Now granted, what you are measuring is "useful" HP, which doesn't take into account losses due to heat and friction, but the system could be calibrated without too much difficulty.

-g.

Surely your indicated HP would massively increase if you were going down hill?

You can buy devices that you stick on your dash and after putting in your cars weight will give you an approximate HP. Think they work off the effects of acceleration though rather than GPS

fair points everyone.. i knew it wouldnt be the most accurate way of doing it..
but i was just throwng a thought out..