Engine Masters. Daily report.

Post by **Stan Weiss** » Thu Nov 26, 2009 6:08 am

OK here is David's first set of graphs.

mbrooks · Post by **mbrooks** » Thu Nov 26, 2009 8:26 am

looks like the 3.2 rear gear would be the best selection from looking at the graph.

David Redszus · Post by **David Redszus** » Thu Nov 26, 2009 12:39 pm

Sometimes the gear ratios discussed do not match the ratios based on gear tooth counts.

For anyone who might be interested, if you send me an email address, I'll send you a gear ratio calculation program that can be used for transmission as well as rear end gear sets.

David Redszus · Post by **David Redszus** » Thu Nov 26, 2009 12:53 pm

Thanks Stan for posting the graphs.

I wrote and lost a post describing the data that the curves represent.
Here is what the graphs are based on.

The torque curve is from an EMC engine; torque curves posted on page 2 by Kwik for a 534 cu in.

Vehicle weight 3400 lbs
Frontal area 24 sq ft
Aero Cd .46
Traction limit 1.25Gs
Tire dia 27.0 in
Drive line losses 15%
Rolling losses 2%

The dashed lines represent the maximum acceleration through the gears for three different rear end ratios.

Any suggestions for changes or alternative data are welcome.