Reduction gear ratio swap?

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Dala

Well-known member
Leaf Supporting Member
Joined
Oct 28, 2018
Messages
464
Location
Finland
Hi,
I recently found this excellent video taking a deep-dive into the Nissan Leaf reduction gear housing
https://www.youtube.com/watch?v=UxJTEXxveUg

Summary, seems like there are two versions of the gearing
7.94:1 for 2011-2013 ZE0 (White interior)
8.30:1 for 2013-2017 AZE0 (Black interior)

This would explain why the first gen seems a bit peppier than the second generation.

Do we know if these can be swapped between versions? Both ways would be interesting, the ZE0 version is better for quick acceleration, and the AZE0 is better for energy economy, so it would depend on your usecase what you desire. Anyone tried this?

EDIT: Further research on this has proved the opposite. The ratios should be turned the other way, 1:7.94 accelerates slightly slower than the 1:8.30 version!
 
The change in acceleration is from a change in the magnets in the motor and in programming. This happened for 2013, while the first gearset was still in use.
 
you have the gear ratios backwards maybe? a lower gear ratio will result in slower acceleration, a higher gear ratio will result in faster acceleration because it multiplies the torque more. This means the 2013 and up Leafs should accelerate better (very slightly) than the first gens, but have a lower top speed.

interesting that it is different, i didn't know that myself. i suppose the change came along with going from a separated motor levels in 11-12 and integrated vertical stack of stuff in 2013 and up.
 
estomax said:
you have the gear ratios backwards maybe? a lower gear ratio will result in slower acceleration, a higher gear ratio will result in faster acceleration because it multiplies the torque more. This means the 2013 and up Leafs should accelerate better (very slightly) than the first gens, but have a lower top speed.

interesting that it is different, i didn't know that myself. i suppose the change came along with going from a separated motor levels in 11-12 and integrated vertical stack of stuff in 2013 and up.

No, the original poster was correct. The low number transmission will be peppier.. Just like the front crank on a bicycle. The larger chain ring will improve top speed, and the middle chain ring will improve acceleration.

This is interesting that there are several versions of the transmission... However, the original poster cannot be thinking of changing his transmission just to get a different one? That would be foolish. Really foolish.
 
That's where my logical thinking brought me too. So the 7.94:1 is better for acceleration. Topspeed is irrelevant, since it is software limited to 150km/h, so it would be very interesting to time some 0-100 testing with the two different ratios.

Why do you think it be foolish? You can get the gears or the whole case for quite cheap.
 
top speed is limited by motor max speed to some extent also, which i am not sure how close we are to hitting, but you're right, software limits it primarily.

i think you guys are looking at the transmission backwards, the small gear is the input shaft, and the large gear is the output shaft. The more turns the input gear does, for each rotation of the output gear, the faster (easier) you will accelerate (just like on a bicycle as referenced above), thus 8.3:1 being faster at accelerating than 7.9:1. Unless the leaf transmission is completely backwards from a normal car gearset, then i have been confused the whole time as the ratio should be 1:8.3.

Marko
 
My 2011 could use some extra towing grunt.
But it's only about a 4.54% difference.
For a pickup truck a slight change in axle ratio can be the difference between base and off road or towing package.
But the difference between standard and off road or towing gear ratios is more like a 10% change.

On gasoline powered street cars they always want the numerically higher ratio for better acceleration.

If all first Gen leaf cars peak at 210 ft•lb of torque then early cars make 1,667 ft•lb to the wheel and later cars make a tire smoking 1,743 imperial units of torque.
 
Looks like it should be good for about 1g acceleration--anybody ever use a g-analyst or similar tool to measure it?
 
nlspace said:
Looks like it should be good for about 1g acceleration--anybody ever use a g-analyst or similar tool to measure it?

that's a neat thought, my estimates based on a 1500kg car with 8.3:1 gearbox and 24.9 inch diameter tire indicate that 1g of acceleration requires 413 lb-ft at the motor. If the motor can put out 210 lb-ft, then max acceleration is right around 1/2g. This is assuming no losses from friction and gearbox (perfect world). The number will drop a bit as we add in motor and wheel inertias as well as friction losses.

oilpan, i agree that only a 4.5% difference will make it very hard to measure acceleration difference in a real world comparison.

in pure math, the difference seems to be around 2% faster acceleration between the two gearboxes.
 
4.5% more torque with the early more aggressive motor/inverter ramp up rate might be fun.

Now if only we could find someone who sells modded VCUs.
 
Dala said somewhere that he will start looking into getting more power through the VCM. Dala, let me know if you need help with testing!
 
LeftieBiker said:
The change in acceleration is from a change in the magnets in the motor and in programming. This happened for 2013, while the first gearset was still in use.

Perhaps the drive ratio was increased a bit to recover some of the low-end acceleration after the motor change?
 
Nubo said:
LeftieBiker said:
The change in acceleration is from a change in the magnets in the motor and in programming. This happened for 2013, while the first gearset was still in use.

Perhaps the drive ratio was increased a bit to recover some of the low-end acceleration after the motor change?

Maybe, but what happens is the 2013 cars are slower off the line, but accelerate a little faster at higher speeds, to get to 60 at the same time, more or less. That is completely consistent with the ratio staying the same and the power curve changing.
 
I looked up the specifications in the service manuals. The difference in ratio is due to a change in the number of gear teeth on the first driven gear from 31 to 32. The numbers of teeth on all other gears are the same so I suspect the change was made for ease of manufacturing rather than specifically to change the ratio. The difference in acceleration between the 2011/2012 models and 2013-2017 models is primarily the programming that limits torque if you floor the accelerator on 2013 or later units.

My 2011 would give all it had to offer if I just floored the accelerator. I thought my 2015 was significantly slower until I met someone from the test track who told me to feather the accelerator instead of flooring it. The 2015 was almost as quick as the 2011 if I feathered the accelerator just right, but it was hard to be consistent--the 2011 would have been much better for bracket drag racing because it was consistent. The 2019 also benefits from feathering, but the OEM tires also limit maximum acceleration (very easy to light the traction control indicator) since they are dealing with twice the horsepower. Still, I would gladly purchase a "performance chip" to get instant accelerator pedal response if one were available in the USA and it would not impact warranty coverage.
 
Wonder why Ben measured 8.25:1 (average of 2 tests) when the calculated was 8.3044:1 ?

calc. = (75/17)(32/17) = 8.3044

Also he said the wiki was reporting 7.94:1, but based upon Gerry's finding the calculated would be

(75/17)(31/17) = 8.0449 : 1

For sure the error or difference is on the order of 1% or less, but still that seems excessive. Is there considerable backlash or clearance in the meshing of the gear teeth to account for that difference?
 
From service manuals:
2011 Input shaft gear: 17 teeth
2011 Intermediate shaft gears: 31 teeth, 17 teeth
2011 Output shaft gear: 74 teeth

2015 and 2019 Input shaft gear: 17 teeth
2015 and 2019 Intermediate shaft gears: 32 teeth, 17 teeth
2015 and 2019 Output shaft gear: 74 teeth

2011 RE1F61A Reduction Gear Ratio:
(74/17)(31/17)=7.9377

2015 and 2019 RE1F61B Reduction Gear Ratio:
(74/17)(32/17)=8.1938

Difference in overall ratio is about 3.2 percent.
 
Way to go Gerry, Thanks for looking up the gears, and that explains it--Ben failed counting teeth in school. i tried to count the teeth from the video but it was too jumpy for me, and i just trusted Ben's numbers.
 
Any leads on performance VCUs?
I have a 2011 with over 70,000 miles, the warranty is moot at this point.
I would like to see what it can do going from 0rpm to full torque and then some in less than a second.
 
I don't think that the NISMO chip does more than remove the WFO throttle restriction on the 2013+ Leaf, and maybe get to full throttle a bit faster in the pedal travel. My evidence? No stories of Japanese NISMO Leafs performing any remarkable feats of acceleration. The best mod would be the ePlus inverter in a 30 or 40 KWH Leaf. I'm not sure how well it would work with a 24 - you'd probably have to use full throttle only when above 80% charge.
 
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