Question 1

Q- What are the benefits of using an electric vehicle gear reducer (TTI Brand: TorqueBox®)?

Accepted Answer

A- Gear reduction multiplies the available torque of a motor an amount equal to the reduction ratio. Keep in mind the reduction also reduces driveshaft rpm by a factor of the gearbox ratio. Therefore a 2 to 1 reduction doubles the motors torque while a 3 to 1 triples the  torque. Without a reduction gearbox (known as “direct drive”), you would need to use a much larger and more expensive motor to reach the same performance level of a smaller motor with a reduction gearbox.
 
All OE electric vehicles on the road today are running a reduction gearbox of one design or another. All Tesla vehicles run gearboxes and while they are a single speed and do not shift they generally run a reduction ratio between 9 and 12 to 1 in their transaxle system.

Running a TorqueBox® brand gearbox in a vehicle with a gear ratio in the drive axle(s), you simple multiply the TorqueBox® ratio by the ring and pinion ratio to find your final drive ratio (FDR).

example

In a vehicle with a 4.10 to 1 ring and pinion and a 1.90 TorqueBox® you have an FDR of 4.10 x 1.9 = 7.79 to 1, while our new 3.00 to 1 TorqueBox® would give an FDR of 12.30 to 1. To put this math into torque numbers, a motor with 300 lb ft of torque and the 7.79 FDR would be 2,337 lb ft of torque to the tires, while the same vehicle with our 3.00 to 1 TorqueBox® would realize an FDR of 3,690 lb ft of torque to the tires.

Caution: Keep the rpm reduction in the equation! If your motor is rpm limited to 6000 rpm the tire rotation is reduced to 770 rpm with the 1.90 to 1 TorqueBox® while with the 3.00 to 1 TorqueBox®, it is reduced all the way down to 488 rpm and  while this increases torque and acceleration, this will limit your vehicles top speed dramatically. That said the 1.90 to 1 ratio is best for the limited rpm motors and the 3.00 to 1 works well with the high rpm motors.

Note: the numbers and explanations found here are general. Call us or your preferred installer to get the exact numbers and recommendations for your build.

In summary; running a reduction box allows big motor performance from a smaller, more economical motor.

Question 2

Q- What is the best gearbox for my application?

Accepted Answer

A- A TorqueBox® of course. The real question is what ratio TorqueBox® would best suit my vehicle and driving style.
 
Really low budget and most all of the early gas to ev conversions just made an adapter and coupler to bolt the electric motor to the existing "gas appropriate" multiple speed manual transmission. Then they would typically run in either second or third gear. This is very energy inefficient. A proper reduction gearbox saves weight and reduces frictional losses which extends the operating range of the vehicle. A reverse gear is not needed as most electric motors can simply be run backwards for reverse.

Question 3

Q- What reduction ratios are available in a TorqueBox®?

Accepted Answer

A- We have marketed a 1.90 to 1 ratio-based reduction gearbox under the TorqueBox® name for over ten years.
	
At SEMA 2023, we debuted a re-designed planetary reduction gearbox  with a 3.00 to 1 ratio. With these two TorqueBox® ratios, we have an ideal ratio for 95% of the single ev conversion market. We also debuted a new non-planetary Dual Motor "Torque Vectoring Capable" TorqueBox® and initially offer this in three ratios: 3.80, 5.14, and 5.62 to 1 reduction ratios.

Question 4

Q- Is the ev TorqueBox® a manual or automatic transmission?

Accepted Answer

A- The ev TorqueBox® is based on a planetary gear system like found in automatic transmissions but is a single speed that does not shift.  This box is more accurately referred to as a reduction gearbox or gear reducer. The planetary gear system requires Synthetic ATF fluid and can be damaged by running any other lubricant. Never run a motor oil or gear oil in a planetary-based TorqueBox® brand reduction gearbox.

Question 5

Q- Can an ev TorqueBox® be customized or upgraded for better performance?

Accepted Answer

A- While not every vehicle needs its TorqueBox® customized we do offer several upgrades for performance improvements when they are needed. 
 
For performance vehicles, we offer micro shot peened sun gears. The driven or reaction sun gear is splined to the input shaft and turns at motor speed while driving three pinion gears. The fixed sun gear does not move but is in constant mesh with three pinion gears. Think of each sun gear as being in a fight against three other gears at the same time. The wear rate is then potentially three times that of a single pinion gear and this is why we recommend shot peening of these two vital gears. In extreme performance or in HD commercial applications we recommend shot peening the entire gear set.
 
Most all transmission gears are made from 8620 steel alloy, this is a great material that balances strength and longevity. When the vehicle is an extreme performance (over 500 HP) or HD commercial (over 10,000lbs) and strength outways longevity, then we recommend our Extreme Performance EN-36 material gear set with all gears getting the shot peen process.

Question 6

Q- How can I be sure that a TorqueBox® will fit in the tunnel of my vehicle?

Accepted Answer

A- The TorqueBox® was designed to fit in tight tunnels and compact spaces. A diameter of only eight (8) inches and length of 10-12 inches allows this unit to fit in tunnels of cars like '65 Mustangs, Mazda Miatas and MGs.

Question 7

Q - Can the TorqueBox® handle electric motors with high torque and high rpm?

Accepted Answer

A - A re-sounding yes!

The 1.90 TorqueBox® can handle upwards of 12,000 rpm and 900 Nm of torque in it stock form and even more with a few optional upgrades. Our new 3.00 TorqueBox® can handle up to 20,000 rpm and is rated at up to 1200 hp and 1200 ft lbs of torque right out of the box and without any upgrades from stock.

Question 8

Q- Are there any specific maintenance requirements for the ev TorqueBox®?

Accepted Answer

A- Yes, the  ev TorqueBox® runs on a very small amount of synthetic ATF and so should be changed annually or every 7000 miles, whichever comes first.

TTI installs a max temperature sticker on every TorqueBox. The sticker records the highest temperature reached.

All TorqueBoxes are dyno tested to 200 degrees F. The sticker registers to 230 F. If in operation a specific vehicle runs the sticker above 225 degrees F, even once, then we recommend an external pump and cooler be added to the system to offer longevity to the TorqueBox.

Remember, the 100% synthetic ATF is the lifeblood of the TorqueBox, keep it under 225 degrees F and clean, and you can expect a long gearbox life and loads of fun.

Question 9

Q- Can I use motor oil or gear oil in a TorqueBox®?

Accepted Answer

A- Our planetary-based TorqueBox® units use directed splash lubrication and rely on oil misting to lubricate some of the most critical areas. Only a full synthetic ATF fluid has the unique misting qualities needed.

However, our Dual Motor Torque Vectoring Capable TorqueBox® is  not planetary-based and here we do recommend a full synthetic 75W90 gear oil.

Question 10

Q- Can the TorqueBox® be used in marine applications?

Accepted Answer

A- Yes, we have been used in numerous inboard and even a few outboard applications.

Frequently Asked Questions

The EV conversion industry is new and growing by leaps and bounds. Information that is pertinent today may not be so tomorrow. If you don't find answers to your specific questions here, please contact us.