1989-1990 Sentra B12 with GA16i-- 4 and 5 speed transmissions These are the ratios for the RS5F31A five speed... 1st Gear 3.333:1, 2nd Gear 1.955:1, 3rd Gear 1.286:1, 4th Gear 0.902:1, 5th Gear 0.733:1, Reverse 3.417:1 Final drive ratio 3.895:1 And here are the ratios for the RN4F31A four speed... 1st gear 3.333:1, 2nd gear 1.955:1, 3rd gear 1.286:1, 4th gear 0.902:1, Reverse 3.417:1 ** Final drive ratio 3.650:1 ____see note below 1989-1990 Pulsar N13 with GA16i RS5F31A 5 speed has 1st gear 3.063:1, 2nd gear 1.826:1, 3rd gear 1.207:1, 4th gear 0.902:1, 5th gear 0.756:1, Reverse 3.417:1 Final drive ratio 4.167:1 เครียดเว๊ย
I figured out my mistake the RN4F31A in the B12 has a 3.650:1 diffrential. The B12's RS5F31A has a 3.895:1 diffrential. Where they say it is the final frive ratio I was confused, they are talking about the diffrential's gearing, not the overall ratio between the input and output shaft. So the B12 Sentra's 5 speed overall ratio would be: 5th gear (.733:1)X diff ratio (3.895:1)= 2.855:1 and the B12 Sentra's 4 speed overall ratio would be : 4th gear (.902:1)X diff ratio (3.650:1)= 3.292:1 and the N13 Pulsar's 5 speed overall ratio would be: 5th gear (.756:1)X diff ratio (4.167:1)= 3.150:1 That means for the transmissions that the N13 Pulsar's 5 speed is slightly higher geared than the 4 speed from the B12 Sentra To compare 3,000 RPM in Sentra 5 Speed= 73MPH 3,000 RPM in Sentra 4 Speed= 63MPH 3,000 RPM in Pulsar 5 Speed= 66MPH 2,000 RPM in Sentra 5 speed= 49MPH 2,000 RPM in Sentra 4 speed= 42MPH 2,000 RPM in Sentra 5 speed= 44MPH
