gear ratios

[qr25sentra]

1st 3.65
2nd 2.05
3rd 1.37
4th 0.97
5th 0.76
Reverse 3.47
Final Drive Ratio 3.53

Overall Top Gear 3.2

im not too familiar with these,is this geared for strong 1st and 2nd gear but starts to die at 4th and 5th?Can anyone explains how this works?

[drdisque]

this shows that third and fourth are low for top speed and good highway mileage and first and second are tall for fast acceleration. What you give up is close ratios and the fact that 5th is so short you'll almost always have to downshift to pass on the highway.

[qr25sentra]

short is acceleration,tall is top speed.
BTW these were the gear ratios for the srt-4.

[Evil Result]

if you engine puts out 200 ft/lbs of torque with those gear ratios and a tire diameter of 19 inch's with 12% drive train loss your putting down 1433 ft/lbs of torque to the ground.

[curtis73]

Wow. I never realized how way far apart they are !!! That's way too far apart for the SRT's torque curve. No wonder it felt so sluggish

By the way, the top gear final is 2.68 with those numbers.

I'm not sure I understand your question, but although it looks arithmetic, the increase in gearing reduces torque by a factor of its percentage of change. In first gear, the torque is multiplied by 3.68 in the tranny, then another 3.53 in the axle. 100 ft-lbs in first gear becomes 368 after the tranny, then 1299.04 at the hub. (significantly less at the radius of the tire) The first gear total torque multiplication is 12.99. The second gear torque multiplication is only 7.24, which is a difference of 44%. Simply shifting from first to second (although it looks like a simple small move) drops you to 44% of the torque you had in first. Each gear change effects a similar drop in multiplication, so by the time you get to fourth and fifth, you are only transferring a fraction of the torque to the wheels you once were.