home dyno?
Super Moderator
Joined: May 2001
Posts: 11,851
Likes: 2
From: Rancho Palos Verdes, CA
Vehicle: 2008 Toyota Prius 2006 Suzuki SV650S
Great idea in theory, however in practice, it is subject to so many errors in variables that the output is worthless.
What it basically does is record when the spark plugs fire. The faster the RPMS rise, the faster the sparks occur, the more power you have.
So by knowing WHEN the plugs fired...how fast RPMS went up...divided by vehicle weight...add in some gear ratio information...and viola! You have HP and torque readings!
But...since our cars use a "waste spark" ignition system...our RPM's would have to be divided in half.
Also... you need a perfectly flat, level, smooth place to do your run, and you need to do "balls to the wall" full out acceleration. Since the System cannot sense wheelspin, that factors in to the calcuation...as does air tempature and air density, wind..etc..etc..etc..
I would spend my money on a G-Tech pro before this...but for my money...spend it on 2 real dyno runs.
What it basically does is record when the spark plugs fire. The faster the RPMS rise, the faster the sparks occur, the more power you have.
So by knowing WHEN the plugs fired...how fast RPMS went up...divided by vehicle weight...add in some gear ratio information...and viola! You have HP and torque readings!
But...since our cars use a "waste spark" ignition system...our RPM's would have to be divided in half.
Also... you need a perfectly flat, level, smooth place to do your run, and you need to do "balls to the wall" full out acceleration. Since the System cannot sense wheelspin, that factors in to the calcuation...as does air tempature and air density, wind..etc..etc..etc..
I would spend my money on a G-Tech pro before this...but for my money...spend it on 2 real dyno runs.
