Gear ratio calculations…
4th gear 1:1 – 31” tires, 4:10 ring & pinion – at 79 MPH (my freeway speed) = 3862 RPMs
5th gear 0.8:1 – 31” tires, 4:10 ring & pinion – at 79 MPH (my freeway speed) = 2809 RPMs
Gear ratio calculations…
4th gear 1:1 – 31” tires, 4:56 ring & pinion – at 79 MPH (my freeway speed) = 4396 RPMs
5th gear 0.8:1 – 31” tires, 4:56 ring & pinion – at 79 MPH (my freeway speed) = 3124 RPMs
The peak torque “sweet spot” with this engine rebuild (261C cam+DT header), according to my desktop dyno, is between 3100 to 3300 RPMs (it may be different on the street and when chassis dyno’d) As Snowtoy pointed out, his butt dyno likes the snappy lower gear ratio. I may end up spending the money to swap in 4:56 ring & pinions.
Gnarls.
Time for a remedial math class.....
3862 * .8 = 3090
4396 * .8 = 3517
3862 * 4.56 / 4.10 = 4295
Are you at least sure about the 3862 ?
