[guptad42]

By this logic, Nexon EV can become a great highway cruiser just by adding a second gear optimised for 80-100 kmph, in addition to the current single speed gearing for 50-60kmph?

If it is so easy to extend highway range from 150-160 km to 250-270km, is it not a relatively cheap thing for Tata Motors to do?

Keep the same battery pack, just add a 2nd gear with a simple electric valve/relay to change the gear position. Will probably be hardly 15,000 -20,000 rupees per car.

[jasjotbains]

@stuntfreak - Noob question below

If you have been able to get such a great range with addition of a gearbox, what is stopping the EV manufacturers from plonking in a gearbox? Will it not help address the range anxiety to quite an extent?

[falconion]

Originally Posted by jasjotbains

@stuntfreak - Noob question below

If you have been able to get such a great range with addition of a gearbox, what is stopping the EV manufacturers from plonking in a gearbox? Will it not help address the range anxiety to quite an extent?

Tesla tried the 2 speed gearbox, but it was found to be unreliable and would be complicated with higher maintenance. They went through several gearbox designs and ended up saying single speed gearbox is better.

The less parts the better and more efficient. The idea being moving away from traditional car making and not making parts overly complicated.

[jasjotbains]

Originally Posted by falconion

Tesla tried the 2 speed gearbox, but it was found to be unreliable and would be complicated with higher maintenance. They went through several gearbox designs and ended up saying single speed gearbox is better.

The less parts the better and more efficient. The idea being moving away from traditional car making and not making parts overly complicated.

Thanks Falconion

Hope then Tata can bring out motors which are highly efficient upto the 80kmph mark. Driving above that will introduce avoidable high wind resistance and drag, overcoming which wastes previous battery juice.

[stuntfreak]

Originally Posted by Mortis

Awesome project and execution ! As a fellow Dzire owner I may just opt for your services down the line.
Also would you be able to make a 48V mild hybrid system ? Basically just some torque and efficiency boosting without any all electric range

Youre most welcome to opt for the conversion kit. Drop in your details on my website and I'll send my car over to you for a drive.

Sorry no hybrids.

Originally Posted by rdst_1

Got it. And as you have said above, you are willing to sell powertrain components to others as well. On that line of thought, do you plan on having kits/components for lower power as well. I will be very keen to making a small electric ATV for use at my farm. And good thing about that will be that it can be designed from the ground up as an electric vehicle and there won't be any requirements of certifications or approvals from the govt as it is only meant to be used for small farm chores.

Yes you can buy our products from my website as per your need.

Originally Posted by guptad42

By this logic, Nexon EV can become a great highway cruiser just by adding a second gear optimised for 80-100 kmph, in addition to the current single speed gearing for 50-60kmph?

If it is so easy to extend highway range from 150-160 km to 250-270km, is it not a relatively cheap thing for Tata Motors to do?

Keep the same battery pack, just add a 2nd gear with a simple electric valve/relay to change the gear position. Will probably be hardly 15,000 -20,000 rupees per car.

You are 100% right. I have not only calculated this but also am currently experimenting on my own nexon ev with this, and IT WORKS. I should not be saying this on a public forum, but for reasons unknown, Tata has opted for a 'not so great' EV conversion Kit entirely from China which is at the moment retrofitted in the standard nexon chassis. Undoubtedly it is a FANTASTIC car, I love it, but the scope of improvement it has is tremendous. I have personally attempted changing the Final Drive ratios and have had huge differences in performance. Whether Tata brings it up or not, I will develop a 2 speed Autobox for the Nexon EV as I am connected with over 1000 users who have lots of issues, specially with range.

Originally Posted by jasjotbains

@stuntfreak - Noob question below

If you have been able to get such a great range with addition of a gearbox, what is stopping the EV manufacturers from plonking in a gearbox? Will it not help address the range anxiety to quite an extent?

Lets answer this question in a reverse way.

How many speed Transmission does a Drag Race Car have?? Just a 2 speed box. Sometimes 3. And yet it's always the fastest one off the line, with the least timing for the quarter mile at the highest speed you can imagine.

Compare this to a mid performance vehicle. It needs like 6-8 speeds to get somewhere closer to being a fast car on the track.

Now let's apply that logic to EVs.

You've got tons of torque, you have a huge Rev Range, then all you need is a single speed transmission optimized for somewhere close to the first gear of the car, and instead of shifting, just rev it up.. and you have speed.. now western countries have a different mentality. Where they go LARGE on everything. Specially the USA. They just dump in a bigger battery pack, and given their fantastic charging and road network, high payout jobs, and variety of finance options, it all works out well. That's where EV technology was born. And it has been a benchmark ever since.

Now compare it to India.. we care about every penny we pay for. Bad charging and road infrastructure. And manufacturers work on low margins. Given in this scenario, the benchmark design is taken, downsized, and used without prior thoughts behind changes needed as per conditions.

This is my thought process. I have been trying out various transmissions on Electric motors for automotive propulsion for the past many years.. I have coupled, studied, tuned, tested all types of electric motors on CVT, torque converter AT, DCT, MT, Direct Drive, Sprocket based shifter, Nuvinci, and even my own patented CVRTS and another of my own patented 2 Speed Zero Shift box.

I may not be 100% right, but I do have results.. not just on paper, but on the field.

Good day mate.

Originally Posted by falconion

Tesla tried the 2 speed gearbox, but it was found to be unreliable and would be complicated with higher maintenance. They went through several gearbox designs and ended up saying single speed gearbox is better.

The less parts the better and more efficient. The idea being moving away from traditional car making and not making parts overly complicated.

Relate to my previous post.

Originally Posted by jasjotbains

Thanks Falconion

Hope then Tata can bring out motors which are highly efficient upto the 80kmph mark. Driving above that will introduce avoidable high wind resistance and drag, overcoming which wastes previous battery juice.

True.

[K a s h]

Congrats on a great EV conversion. This is by far the best I have seen.

Originally Posted by stuntfreak

Whether Tata brings it up or not, I will develop a 2 speed Autobox for the Nexon EV as I am connected with over 1000 users who have lots of issues, specially with range.

Count me in. I'm getting a Nexon EV if you develop this. Range is the only issue stopping me from getting one since i need to do Bangalore-Chennai runs (360 kms) at highway speeds. Looking forward to your updates .

[croupier]

Awesome work stuntfreak. Amazing what you have been able to achieve. I think all your arguments of using a transmission with EVs are valid. Here is an article I remember reading sometime ago, that kind of outlines what you mentioned about how the Americans set the benchmarks and how we are just following them without thinking about local conditions.

https://cleantechnica.com/2019/07/22...-a-good-thing/

[futaboy]

Really amazing project stuntfreak. Is the kit compatible in smaller hatchbacks eg Alto/Wagon-R?
And also getting permission to ride is temporary or is it updated in the vehicle registration.

[efuture]

Hi stuntfreak, your conversion is clean and good.

If you can share some proof for some of your claims

1. 160km/h with a 15kW motor
2. 250km range with a 18kWh battery pack

Originally Posted by stuntfreak

Over my years of work, I have faced many people, who dont invest even one rupee or one minute worth of efforts, time, investment, experiments, but still claim to know everything by just reading books and specs online. I am not saying you are one of them, but many others will pop up with pessimism trying to challenge the results instead of complimenting the product and waste my time. So I have decided not to debate over any topic, with anyone, and let the test certificate do the talking. Please Find attached our Motor's test certificate with the required results which may answer all your questions. Please note that I have intentionally blanked out many areas not applicable to your Questions in the certificate so as to avoid misuse by anyone. Please see the Red Circled area. Also to clarify, Motor and Engine Power are two completely different things. Please do understand that what matters at the end of the day is, Torque. PFA our attached certified torque spec, which we are further over clocking by programming.

Hope you consider this reply positively.

Cheers brother.

Cheers

I wanted to skip the specification part as I doo not want to waste your valuable time. Still I feel it is absolutely necessary to point this out here. Is 170Nm the actual torque that the motor can deliver all the time?

Note: When someone post something related to their project on a public forum, the author is bound to answer the questions thrown at them. This is a forum for open discussion and if the author is not comfortable with hard questions, either the author must not have posted the content or should answer appropriately.

Note to mod: Over the last few months lot of misleading information's were posted related to electric vehicles which is not the standard of this forum. Request mods to filter out those posts and maintain the standards.

[stuntfreak]

Originally Posted by efuture

Hi stuntfreak, your conversion is clean and good.

If you can share some proof for some of your claims

1. 160km/h with a 15kW motor
2. 250km range with a 18kWh battery pack



I wanted to skip the specification part as I doo not want to waste your valuable time. Still I feel it is absolutely necessary to point this out here. Is 170Nm the actual torque that the motor can deliver all the time?

Note: When someone post something related to their project on a public forum, the author is bound to answer the questions thrown at them. This is a forum for open discussion and if the author is not comfortable with hard questions, either the author must not have posted the content or should answer appropriately.

Note to mod: Over the last few months lot of misleading information's were posted related to electric vehicles which is not the standard of this forum. Request mods to filter out those posts and maintain the standards.

Youre right, I apologize for sounding rude in my previous post. I should have been more suttle on my reply with scientific evidences (which have been provided). I hope all the members and Moderators take this message positively for a better EV future together.

Will create a video showcasing speed and consumption soon and post the needful on my YouTube channel. Will share a link once ready..
As it will take time to get the appropriate permissions and a track to showcase the top speed as legal limits are upto 100kmph only. However, it shall be done, and I shall post the Video with the necessary instruments in place soon.

The torque mentioned is peak, but given real world driving conditions, there is very very rarely an event when its not available and the motor or controller lacks to provide it.

Thanks

Originally Posted by futaboy

Really amazing project stuntfreak. Is the kit compatible in smaller hatchbacks eg Alto/Wagon-R?
And also getting permission to ride is temporary or is it updated in the vehicle registration.

We are working on long term permissions with RC change, but as of now we have only on test permissions for a year.

Originally Posted by croupier

Awesome work stuntfreak. Amazing what you have been able to achieve. I think all your arguments of using a transmission with EVs are valid. Here is an article I remember reading sometime ago, that kind of outlines what you mentioned about how the Americans set the benchmarks and how we are just following them without thinking about local conditions.

https://cleantechnica.com/2019/07/22...-a-good-thing/

Thanks buddy

Originally Posted by K a s h

Congrats on a great EV conversion. This is by far the best I have seen.


Count me in. I'm getting a Nexon EV if you develop this. Range is the only issue stopping me from getting one since i need to do Bangalore-Chennai runs (360 kms) at highway speeds. Looking forward to your updates .

Thanks buddy

[yashcosmos]

Amazing work, love the spirit of you trying and testing so many things, regardless of the result. Though, one thing that I feel is not worth the experiment (for others, not you) is changing the Tata Nexon EV gearbox. Simple reason, that will void the warranty on the car and you are gambling a 8yr battery pack warranty for extending a bit of range. Now, for some reason, these batteries which are not tried and tested in actual world conditions for more than a year happens to give up on the owner, Tata would easily blame the alterations to the Gearbox. For someone like the OP that isn't a big deal since he's being playing in and out with EVs and would resolve it at his end, but for a normal customer it's way too much to gamble for extending a bit of range.

[stuntfreak]

Originally Posted by yashcosmos

Amazing work, love the spirit of you trying and testing so many things, regardless of the result. Though, one thing that I feel is not worth the experiment (for others, not you) is changing the Tata Nexon EV gearbox. Simple reason, that will void the warranty on the car and you are gambling a 8yr battery pack warranty for extending a bit of range. Now, for some reason, these batteries which are not tried and tested in actual world conditions for more than a year happens to give up on the owner, Tata would easily blame the alterations to the Gearbox. For someone like the OP that isn't a big deal since he's being playing in and out with EVs and would resolve it at his end, but for a normal customer it's way too much to gamble for extending a bit of range.

Yes you're absolutely right. But I do know many people willing to give up warranty to enhance usability and get the ROI out of the vehicle while it lasts.. anyways, I'm not looking at it from a commercial angle so don't expect returns on this particular upgrade. Anyways lets hope TML can replace battery packs when if and when the ones given go kaput due to whatsoever reason..

Cheers buddy.

[vamsi.vadrevu]

Originally Posted by stuntfreak

What my argument is that: Just because a motor can spin really really fast, doesnt necessarily mean its efficient while doing that!

This is exactly where adding a gearbox helps. This is the same reason the Nexon EV Returns a range close to 300 Kms on a single charge if driven at 50 kmph, on a light foot, where as with the same type of throttle input, the car will be extremely inefficient say at 100 kmph where it will return just 150 kms on a single charge. There may be other factors at play here, like aerodynamics and stuff. But consider the efficiency drop in a Nexon Petrol at 50 kmph vs 100 kmph, and consider it in a Nexon EV at 50 and at 100.

Adding a multi speed transmission helps you drive the vehicle with the motor in its sweet spot.

I thought that electric motors could be configured to be efficient in all RPM ranges. By using Variable Voltage and Variable Frequency Drives (VVVFD), we could use just an AC Induction Motor to produce maximum torque at zero RPM and also produce maximum power at it's highest rated RPM. This is achieved by changing the voltage (thereby current) and frequency of the AC input to the Induction Motor.

Adding a gearbox would only add weight. Instead, it would be cheaper to add a Voltage and Frequency controller circuit and change the Motor characteristics at different RPMs via software.
This is the same approach Tesla uses in its cars.
However, if we're using Permanent Magnet DC Motors, our Torque characteristics would be limited, and in such cases, a gearbox would make more sense.

[stuntfreak]

Originally Posted by vamsi.vadrevu

I thought that electric motors could be configured to be efficient in all RPM ranges. By using Variable Voltage and Variable Frequency Drives (VVVFD), we could use just an AC Induction Motor to produce maximum torque at zero RPM and also produce maximum power at it's highest rated RPM. This is achieved by changing the voltage (thereby current) and frequency of the AC input to the Induction Motor.

Adding a gearbox would only add weight. Instead, it would be cheaper to add a Voltage and Frequency controller circuit and change the Motor characteristics at different RPMs via software.
This is the same approach Tesla uses in its cars.
However, if we're using Permanent Magnet DC Motors, our Torque characteristics would be limited, and in such cases, a gearbox would make more sense.

Our Motor controller has a VVFD.

Again. Theory va practicality. We have been experimenting from the past 8 years on this. A gearbox has proven to be useful with better results.

[joelstephen]

Have you implemented regenerative braking?