[changzuki]

Originally Posted by narclepticfool

This is going to be pretty sweet if you can get it worked out. With the extra gear and the OD, have you figured the new top speed? Think this is going to improve your MPG, or just give you a higher top speed?

Excellent questions! I do have an rpm/speed chart based on the components being used... The calculations only do rpms in "x" increments or rpms for a given speed.
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Here is the breakdown:
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The "top speed" target is going to be exactly "88 miles per hour" because:
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http://www.youtube.com/watch?v=JFT7hNhop7w

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The big question will be the fuel economy boost or bust. I believe like any vehicle, that will depend on how it's driven. What I don't know will be the overall impact on fuel economy based on:
1) The extra weight of the larger 4-speed with Laycock overdrive
2) Any losses used to drive the pump in the Laycock overdrive

The stock three rail transmission is quite small and heavy for its size (but not heavy overall, maybe 35 pounds).
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It is shown below for reference:
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More to come of course!
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~CrazyJerry