em1gangsta

wat does the final drive gear ratio? and what does it do?

BlueIntegraBoy

iTrader: (5)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Googled &raquo;</TD></TR><TR><TD CLASS="quote">Final Drive Ratio: This is the ratio of the gearset (usually the differential) that is farthest from the engine. A ratio of 4.40:1 means the driveshaft turns 4.40 times for every one turn of the wheels. Generally speaking, the higher the number, the better the vehicle's initial acceleration and pulling power. The lower the number, the better the vehicle's fuel economy.</TD></TR></TABLE>

em1gangsta

thanks...jst a burning question i had.

Syndacate

Just another note: The final drive ratio is the "rear end" that people usually refer to when talking about muscle cars, the higher the number, the lower the rear end, the better your acceleration and the faster you top out in each gear.

It's called a "final drive" here - but because it's the last gear in a RWD car (and in a FWD for that matter, but in a RWD it's also the furthest back) it's commonly referred to as a rear end.

I don't really like the definition posted above so I'm going to go out on a limb here:

Every output path (each gear) has two ratios - the gear ratio and the rear end.

So if you're in first with a Z6 transmission - your rotational power (through the amplification as X number of times one shaft turned to Y number of times the other shaft turned) - you have a 3.25 first gear, then a 4.25 final drive ratio, so your (everything) gets amplified by those two, so it creates something similar to X * 3.25 * 4.25 = output. Then obviously the number changes with each gear, so in 2nd it would be X * 1.9 * 4.25 - so on and so forth till the 5th which is X * .702 * 4.25. That equation - replace for X for torque, HP, and number of rotations, they are all amplified by the same amount.

Hope that helps explain it a little more...I don't like that definition .

PS: As far as the above definition goes - it's not 100% accurate. The lower the final drive the better your gas mileage is ON THE HIGHWAY - though for a city or town like area a slightly higher final drive will net you better gas mileage as you don't have to A) wind each gear out as long in order to not bog the next gear down, B) You can shift earlier and still be in torque without bogging the motor, and C) You don't have to give it as much gas for hills and the like.

em1gangsta

that does help. it explains a lot more about it, and it seems a lot of math is involved. i gues thats engineering for ya. thanks.