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Old 12-19-2008, 03:45 AM   #10 (permalink)
almightybmw
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Join Date: Jul 2008
Location: Bozeman, MT
Posts: 248

Daily Driver - '02 Pontiac Grand Prix SE
90 day: 18.45 mpg (US)
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Quote:
Originally Posted by i_am_socket View Post
I'd have to check what my current 65 RPM is; been a while since I drove that fast. I'm @ ~2100 RPM doing 55 MPH with the current auto.

*edit* that calculator is pretty handy. So, by inference from the calculator, I'd actually want a lower final drive to increase speed at a given RPM?
Lower final yes produces lower rpm to tire speed. Think of it this way if you ever get confused again: Your engine rotates at 2000rpms. Tire dimensions given say 766rpm (random number). That's a ratio right there, 2000:766, mythical ratio I made up is 2.61:1. Remember, this is all revolutions per minute. If your engine rotates 1rpm, wouldn't you want your car to move forward on the tire 1rpm? That'd be pretty impressive gearing (assuming a reasonably sized tire).

/end ratio tangent.
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