![]() | #46 |
BHPian Join Date: Oct 2016 Location: Bombay
Posts: 242
Thanked: 1,149 Times
| ![]() Hi! Great job with the Beat. A few questions: Where are you getting the motor and the batteries from? Are the batteries modular, can the packs be shaped to integrate/fit anywhere? Are you coding the electronics yourselves? What about the info-screen tablet and its interface? Thanks. This is truly inspirational. |
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![]() | #47 | ||
BHPian ![]() Join Date: May 2005 Location: Pune
Posts: 192
Thanked: 1,227 Times
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Gear box: 1. Regarding a single speed transmission, one needs to understand that the selected motor needs to cater to the max load conditions and max torque requirements while also achieving the needed top speed. Given that the motor availability is limited, instead of choosing for a higher torque and rpm motor, we decided to opt for a slightly smaller one which saved cost and battery size, weight and price as well. The motor used works on the car in a single gear - 2nd throughout absolutely fine unless you make 4 ppl sit in the car and go to a heavy incline. That’s when the first gear is absolutely necessary else the car would be stuck. Unlike an OEM, conversions have their limitations. Also utilising the existing gearbox assures me reliability for the differential, drive shafts, oil seals, and a lot of things that otherwise would be difficult but not impossible to make It’s more of a make and buy decision for this particular application. However in theory it makes more sense to optimise the entire system for a single speed transmission. The gear ratios for the beat diesel are quite tall. And my motor does 8500 rpm. I can use the car in second gear from 0-100 kmph without an issue. If it were a petrol car I would have probably used 3rd gear. May be. Check out our upcoming builds on the use of DCT, AT, CVT, Single speed on EV converts 😉 stay tuned. Quote:
The electronics and coding is done by my team yes. All in-house. Last edited by moralfibre : 25th May 2020 at 13:57. Reason: Back to back posts. | ||
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![]() | #48 | |
BHPian ![]() Join Date: May 2005 Location: Pune
Posts: 192
Thanked: 1,227 Times
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😉 Enjoy. Cheers. | |
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![]() | #49 |
Newbie Join Date: Mar 2019 Location: Bangalore
Posts: 14
Thanked: 13 Times
| ![]() Soo cool! I'm a fan of everything except coming down to personal taste, those wheels ![]() Great pics, phenomenal job! |
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![]() | #50 | |
Senior - BHPian ![]() | ![]() Quote:
The machining is almost top level and looks like a factory install. Keep it up and keep posting Best Regards & Drive Safe | |
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![]() | #51 |
Newbie Join Date: Sep 2019 Location: Mumbai
Posts: 5
Thanked: 3 Times
| ![]() This is amazing!! Hats off to you for pulling this. Please keep posting the project details of Maruti 800, I am sure to follow the post. |
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![]() | #52 |
BHPian ![]() Join Date: May 2015 Location: New Delhi
Posts: 56
Thanked: 238 Times
| ![]() First let me congratulate you for an excellent as well as a very intriguing conversion. I just have a few noob questions ![]() From what I understood, you retained gearbox because of the low power of the motor. But, in doing this, is some efficiency being sacrificed (additional weight and moving parts)? To the best of my knowledge, EVs are very efficient because of their minuscule number of moving parts compared to an ICE car. Also, I believe only the Porsche Taycan is the only stock EV that comes with a two speed gearbox. You have mentioned that your future conversions include CVT, dual clutch gearboxes etc. But wouldn't it be simpler and more efficient if you had just gone for a higher powered motor? You mentioned that you have done away with the 3rd, 4th and 5th gears. If you had kept the first(for fully loaded starts), and then used the fifth gear(removing 2nd, 3rd and 4th), would it have resulted in higher speed and more efficient cruising? Your batteries are placed inside the car, under the seat and in place of the spare. Would it be a hazard in places like Delhi, where it's almost touching 45 degrees for several days now? Also, since the interiors is guaranteed to be several degrees hotter than the outside, will it make the batteries wear out sooner? Eagerly waiting for your Maruti 800 conversion. |
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![]() | #53 | |
BHPian ![]() Join Date: May 2005 Location: Pune
Posts: 192
Thanked: 1,227 Times
| ![]() Quote:
1. Motor used is slightly undersized - yes. That’s why I need first gear for extreme conditions - yes. Else I can do with 2nd throughout - yes. Causing additional losses - no not really. So when EVs are compared to ICE the whole talks about less moving parts are on the engine side. All EVs, be it a Tesla , a Mahindra e-verito, a forklift or even a golf Kart, all have a reduction gearbox after the motor followed by a differential. By single speed reduction they mean a fixed ratio. But everything inside remains the same as of my setup except I have one more gear pair which is freely rolling unless engaged. The additional loss of that is not considerable. So efficiency wise the drop between using a single speed transmission vs what we are using is about 98% same. 2. Porsche has learnt now 😜 3. We have had multiple theory and practical trials and even road trials on higher gears. The truth of the matter is, higher gears can provide higher speed at reduced power / torque IF the motor can support it. In case of my beat, even 3rd gear ratio will not be supported by my motor. Let alone 4th and 5th. Not enough torque. Plus contrary to ICE, EV motors prefer being run at high revs. Say I’m at 80 kmph with my motor spinning at 7500 rpm in 2nd gear. And say I engage third, and then at the same speed 80kmph I am say at 6000 rpm,-> My system efficiency will be higher in second at 7500 rpm with lower load on motor and other electronics. So cruising is ideal at higher revs. To increase my speed I need to reprogram the controller to go to Say 9000 rpm and not shift to third gear and add load on the motor and power electronics. Hope this point is clear. 4. I’m not a battery expert, but I prefer LFP chemistry as it’s more reliable and can take the torture. We have 45 deg in Pune and it’s fine. And on the contrary, LFP cells run very efficient between 30-45 deg C. It’s the low temp conditions that damage them. Very good questions. Thanks once again. Stay tuned and you’ll love the 800. Cheers | |
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![]() | #54 |
BHPian ![]() Join Date: Apr 2010 Location: kochi
Posts: 100
Thanked: 101 Times
| ![]() [quote=stuntfreak;4810614]Don't know whether I am jumping the gun, but if you go on a commercial basis, please evaluate the possibility of opening a desk to help the newly converts for these formalities (on a later stage of operation). |
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![]() | #55 |
BHPian ![]() Join Date: May 2005 Location: Pune
Posts: 192
Thanked: 1,227 Times
| ![]() [quote=adityadeva;4810865]Haha. Thanks for your input. Will think over your suggestion. Thanks buddy |
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![]() | #56 |
BHPian Join Date: Oct 2013 Location: Bangalore
Posts: 28
Thanked: 15 Times
| ![]() Very Impressive work Stuntfreak. this is turning out to be a very informative and entertaining thread. Do you have any certification or License/ Recognition of any sort to be making such conversions if it is needed at the RTOs or for the Insurance Purposes. and this build has Batteries under the rear seats and in the Boot/dickey of the car, and that will make the CG of the car more towards the rear axle than the front, have you notices any loss of traction in the front wheels going uphill? or does the weight of the Gearbox and the Motor makes for acceptable weight distribution? |
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![]() | #57 |
BHPian ![]() Join Date: Apr 2006 Location: MUM/CCU/Tokyo
Posts: 217
Thanked: 218 Times
| ![]() Dear Stunt freak. Amazing build and explaination. I have some questions which I would be grateful if you replied. In one of the videos you mentioned the motor matches the ratio of the output shaft and the shift will be smoothly made. So you have sensors that gives the data of speed and then the ECU controls the speed of motor during those few seconds of the gear lever being moved from 1st to 2nd. Very curious for this one a bit of detail on this. Can you down shift, like from 2nd gear to 1st whilst on the move.? Thank you in advance, great build and please keep up the good work. We desperately need a Elon Musk equivalent here. |
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![]() | #58 | ||
BHPian Join Date: Apr 2015 Location: Kuala Lumpur
Posts: 174
Thanked: 253 Times
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![]() | #59 |
BHPian Join Date: Oct 2012 Location: pune
Posts: 132
Thanked: 178 Times
| ![]() WOW ![]() What you have achieved and with the plans you have , more than government initiatives and subsidies , you can make Electric Vehicles more accessible and economical than most OEMs could even think of. Really appreciate you thanking God and your Father for having the setup for you as I too am thankful to both as my business too is a Legacy of my father and I am into automobile engineering. Wont get into technical details as most have already asked all the right kind of questions, but here is a take away- how about converting a Tata Safari to fully electric? You can have mine . The best thing is "APAN PUNEKAR"! Would love to come and meet you soon. Till then looking forward to all the posts on this thread. Cheers! |
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![]() | #60 |
BHPian ![]() Join Date: Apr 2019 Location: Bangalore
Posts: 114
Thanked: 297 Times
| ![]() Sir, I am simply stunned at the EV Beat. Probably the first fully usable, reliable and daily drive EV conversion that I have seen. Few points: Brilliant job in retaining gearbox, this has saved weeks or months otherwise required to make parts that will hold drive shafts and other parts. Is that tablet held firmly by something in the background? Does it have any remote features etc For your next project, my suggestion would be to use a NANO instead of M800. Nano has more space, may be a little lighter too. Battery pack would easily fit in the front Stepney area and also the rear small boot. I have an old activa and always wanted to switch to EV, as I mainly use it for short and frequent rides within city limits. What could be the cost for EV CONVERSION for the same? Is there any readily available kit that you can suggest me? I am a metal fabricator by hobby and should be able to do this as a diy for an activa, with ample guidance from pro's like you. Once again, overall a brilliant job, ![]() All the best. |
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