The ultimate add on?

Discussion in 'Performance Mods' started by andyinchville1, Nov 8, 2007.

  1. HI all,

    As you know I have been searching for ways to improve our motorized bikes and even wanted a way to quantitatively determine which modifications really work and if so how much they actually work.....Normal testing often involves seat of the pants feel or looking on a digital speedo but I was looking for a better way....I came to the conclusion that the Dyno was possibly the way to go but since they are frighteningly expensive I decided to try to build one but still had to sort out the electronics portion of the setup (need to have a RPM counter and timer)....Anyways, I did locate a company that sold the needed equipment (the electronics and software part at least) but was still looking for a better way.....then I ran across this site....(OK I don't know how to do links BUT if you type "g tech pro" under a google search they are the first one that pops up)...Seems like this would do everything needed to determine actual performance....Only thing tho it needs 12 V power which I suppose could be supplied by a lawn mower battery but would have to wonder if it (the machine) could sense the spark to determine engine RPM's....

    Does anybody out there have one in their car?.....Do you think it would work on our bikes?....I do have a call in to the manufacturer but I wanted to know
    if anybody actually had real world experience with this.



  2. jpilot

    jpilot Guest

    My brother tried one out with mixed results. He races boats and was interested in using one to tune his race boat. They sort of work. Measurements are made using an accelerometer. The unit is very susceptible to vibration and must be mounted and stay level. RPMs are measured by sensing the residual AC ripple from the alternator and must be calibrated against an external tachometer. The weight of the vehicle must be entered into the unit. Don't know if it would accept such light weights as a bicycle/rider. With the very moderate acceleration and vibration of these motored bikes I would be afraid that the accelerometer measurements would be lost in the noise.

    If the electronics are all that are stopping you from building your own dyno, check out They sell everything you need including the electronics and software for around $525.

    I'm currently evaluating the use of a computer sound card as the measurement component for an inertial type dyno. The sensing device will be either a hall effect or optical sensor. If I can get a nice square wave out of the sensor into the mic input of a PC, the rest is just software. The sensor electronics would cost around $10. The software is fairly easy but will take some time to develop.

    If you try out the gtech let us know how it works!
  3. Alaskavan

    Alaskavan Guest

  4. Thanks for the responses guys....I will definitely follow-up on this great new info.