Quote:
Originally Posted by StudeChamp
Hello Ecomodders,
So I read MetroMPG's thread on final drive ratios, wanting to confirm that I indeed have a 3.52 final drive tranny from the Suzuki. I duly lined up my timing mark, raised the RH wheel (LH on ground), chalked the wheel, set the car in 5th gear, and turned the crank one full 360. The RH wheel made approx . 75% (maybe 77%) turn. This doesn't correspond the potential results in MetroMPG's thread as I understand it -- what am I missing? Advice, please!
I am going to post in that thread as well. Thanks in advance for your input.
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As I understand it:
You went .77 rotations for one rotation of the engine crank (1 wheel up).
That means .385 actual rotations if you'd had two wheels up.
1/.385 gives you an overall final ratio of 2.597 (insanely good!)
I think the 5th gear ratio in your car is .76, so... 2.597/.76 = 3.42
That last should be your diff ratio, but it seems a little low, maybe measurement?
So let's try your first estimate: if it's .75 rotations to one crank, then it's .375, hence 2.67.
2.67/.76 = 3.51, which seems like it's exactly what you were looking for.
EDIT: If you were at the stock 4.10 diff (I think that's right?), then: 4.1*.76 =3.116... (1/3.116)*2 = .642 rotations of your 1 wheel off the ground per crank turn.