Poor Man's Dyno

[Bootie]

I just came upon an Apple App for iPhones. It uses the accelerometers built into the iPhones to obtain Miles/Hr, Dist, Horse Power, and Forward and Lateral acceleration. It is called gMeter and it costs $8.99 but it's pretty good. Check out their website at www.hunter.pairsite.com/gmeter/
The raw data can be emailed and then incorporated in, for example, an Excel Spreadsheet.
You have to be careful about the setup and calibration but once these things are completed. It has several modes of operation (Manual,1/4mile, 0-60, 60-0)but I mostly used the 0-60 feature. The calculations are based on the acceleration so the data are kind of noisy. Also, the HP is based on vehicle velocity and weight. I think this accounts for an error in the max HP (shown below to be over 150HP).
Anyway, for $8.99 it would be worth it just to play.

The dip in the HP and Forward_g graphs is where I shifted from 1st to 2nd Gear

 

[Bootie]

Here are the results of a single Dyno Run (0-60mph) presented in a more familiar form. The data have been smoothed. The dip in the center is where I shifted from first to second gear. The data are derived from accelerometers in my iPhone. With the vibrating handlebars (to which the iPhone was mounted) the accelerometers were somewhat noisy requiring smoothing of the data.

 

[Bob Denman]

That looks as if it could be a ton of fun!! :2thumbs: How much input of data does it need to compute this stuff?

 

[Dochands]

I've looked at this for my car but how do you set a level and fixed position on your Spyder? Do you have a RAM mount or something?

 

[Bootie]

I've looked at this for my car but how do you set a level and fixed position on your Spyder? Do you have a RAM mount or something?

Yes, I purchased a RAM mount specifically for this purpose. When I am not using the iPhone as a Dyno, I can mount it on the handlebars and use it as an MP3 player and/or Phone.

 

[Bootie]

That looks as if it could be a ton of fun!! :2thumbs: How much input of data does it need to compute this stuff?

Yes, it is a ton of fun. Internally it computes (displays) MPH, Dist.,HP, Forward_Gs, Lateral_Gs.
You can email the numerical results to yourself and then incorporate the results into Excel.

 

[Phil]

Crud.... one MORE app I 'need'. Thanks Bootie!!

 

[Bootie]

Crud.... one MORE app I 'need'. Thanks Bootie!!

There's probably an app for that, too.:roflblack: