final drive ratio vs differential ratio

If you alter this ratio it also alters every gears effective ratio thereby affecting the vehicle performance and economy. VCM Editor Version 329.

2011 2014 F150 Rear Gears Differential Truck Tyres Jeep Tyre Size

373 will get better gas mileage 427 will have more punch and might get more life out of the transmission.

. This is known as the final drive differential gear Crown. 373 means the driveshaft spins 373 rotations for 1 rotation of the tires. There is a large range to choose from.

Differential Gear Ratio also known as Final gear Changing a diff to better suit larger wheelstires is a good idea and in some cases is a must. Ratio is up to you. But it can also reduce your top speed and fuel economy.

Shorter tires require a higher gearing to travel the same distance as a taller tire so as tire sizes got smaller and engines produced more power the gear ratios tended to get higher. To pick the right rear gears you must know the peak torque RPM of your engine the ideal cruising RPM and the speed. This is a great way to improve any Mustang whether its stock or has been highly modified.

Both of the transmissions that i am considering have a 073 final gear ratio but one has a differential ratio if 355 and one has 325. I think a 488 to 1 ratio would be ideal for an automatic. Another way to think of this is the revolutions of the driveshaft which is connected to the pinion ge.

Spend a few minutes in any bench-racing session and soon youll hear rear axle gear ratios discussed. Feb 8 2021. If fitting larger tires to a 4x4 which are 3-4 sizes bigger stock was 30 inch new tires 33-34 inches or even larger than that it will affect the way the vehicle will drive.

I understand how a final gear ratio works it is the relationship betwen engine speed and the wheel speed. The final drive differential gear ratio. The final-drive ratio is the extent to which the rotating speed of the driveshaft output from the gearbox finally reduces before it reaches the driven wheels.

The final drive ratio is what you end up with when you factor in the transmission and transfer case gearing and the axle gear ratio. A final drive is your diff ratio. Final Drive Ratio.

Answer 1 of 2. The axle ratio refers to the revolutions of the pinion gear vs. Using a lower final drive and upgrading to a limited slip differential can improve acceleration.

The front axle and the rear axle will have the same 427 ratio. For many performance cars 373s and 410s are common gear choices. So it accounts for all gears in the drivetrain and axle.

That is why for instance an MGB with 14 wheels was fitted with a 390 gear ratio and the earlier MGA with 15 wheels had a lower gear ratio. So running a 282 rear gear in a 83 overdrive gear would give you the same final drive ratio as running a 234 rear gear and our trans in 4th which is 11 gear I may have missed the boat on what final drive ratio is referring to but Ive always referred to it as the ratio between the crank and the axle drive-train. A lower taller gear ratio provides a higher top speed and a higher shorter gear ratio provides faster acceleration.

There is a lot of confusion in the trucking industry about what is the best gear ratio for pulling power fuel mileage and a good cruising speed. If the ratio is 21 the driveshaft should. With this transmissions First gear ratio of 274 combined with a 373 axle ratio the final drive ratio yields a 1022 274 x 373 1022.

A cars gearing is all about compromise. 427 is well 427 rotations. Final Drive Ratios - E28 Model Rear Axle Ratio 518i 520i 410 520iA 535i-E34-Auto 391 525e 293 525eA 307 525e Cat 293 525i 535i-E34-Man 364 528i 320i-E36 346 528i Sports Gearbox 325 535iM 307.

The two ratios multiplied together equal the final drive ratio. Taller gears allow. Hence the manufacturers term it as the final drive ratio.

I suppose if you were DD on-road only and putting a. Besides the gears in the transmission there is also a gear in the rear differential. I could still do 28MPH in 1st 7000RPMs versus 35MPH in 1st 7100RPMs for the manual410.

How does the differential ratio effect the behavior of the transmission. I think using crawl ratio is ending the conversation too soon just like only using engine hptorque numbers and not talking about the rest of the drivetrain. Get the rear locker.

The engine produces a certain hptorque rating but thats not the end of. The final drive ratio is the last bit of gearing between your transmission and the driven wheels. Overall the final drive ratio of your truck has a minor impact on fuel economy compared to other factors such as low tire pressure overuse of air conditioning an inefficient or neglected engine and frequent rapid acceleration.

This article will pertain to the over the road semi truck NOT heavy haul or vocational local trucking. I see these two components with the exact same description but two different values from a stock 2009 Chevrolet Express 3500 van with a 60 liter V8. Under SPEEDO CALIBRATION GEAR RATIO TIRE SIZE FINAL DRIVE.

GMC Motorhome Turbo Hydra-Matic Transmission gear ratios Information from GMC manuals for standard 307 final drive ratio Transmission Gear Ratios L 1st 2481 up to 551 S 2nd 1481 up to 321 D 3rd 1001 ratio increases up to 21 L and S can be multiplied by as much as 221 depending on the slip. By changing it you can affect the performance of your car rather dramatically in some cases. Final drive ratio is the ratio of engine revolutions to drive wheel.

This would give me the holeshot from a dead stop and still better economy at 60 MPH with a 488 automatics 2326 RPMs versus the 410 manuals 2575 RPMs. There is a little different RPM difference between the two but shouldnt be a big deal. The two terms are often used interchangeably but they arent precisely the same thing.

So if you got a final drive diff of 389 then with an od box you would end up with a final drive figure of 389 share 25 OD ratio 311 and a 370 would be 370 25 296 So a 296 final overall ratio will be better for cruise mpg But only if you got the power torque to pull a higher gear. How Changing Your Final Drive Ratio Can Make Your Car Quicker. According to BMW the following final drive ratios were fitted to the E28.

Final drive is the differential ratio but all of those terms leave out the last gear in the system the tires. Final Drive Ratio This ratio is the number of times the driveshaft needs to spin to get the wheels to spin. Choosing your right gearing is all about compromise.

As of 2019 a 41 axle ratio from the factory shouldnt cost much more than 50. If you have a 1 to 1 gear in the trans then that gears final drive ratio will be the same as the axle ratio. An automobile uses gear ratios in both the transmission and the drive axle to multiply power.

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