openinverter forum

jerrykco wrote: ↑Wed Jan 12, 2022 7:38 pm Looks like 0-3000 RPM full torque. at 3000 RPM car will be doing 55mph. At 5000 RPM 116mph. Not that I want to go that fast.....

RPM ratios and (non)use of reducing gearbox was discussed here https://openinverter.org/forum/viewtopic.php?f=4&t=2137

From experience i can say i have been involved in building a car using Leaf motor with OEM gearbox as well as a car using leaf motor coupled with original transmission, allowing it to shift clutchless.
I got following impressions:
1. Nissan OEM gearbox was clearly calculated with similar car mass and torque in mind. Off the line car feels smooth and there is lots of torque with instant delivery from throttle.

2. Original Mazda transmission allowed use of all the gears. Yes one could driveoff in 5th too, but torque would suffer. The best driveoff was from 2nd, shifting to 3rd for cruising, maybe 4th for going really fast on highway. Downsides of transmission were springiness inside the coupling which would impede direct torque delivery. There was some rattling in 3rd gear which i assume is standard for RX8 transmission where rotary engine is usually ran at.

So I would summarize, transmission is never ideal for electric motor. There is allways some rattling of gears and such anomalies which are now heared since engine does not drown them in noise.
Motors own OEM gearbox is allways considered optimal.

Thanks for all the feedback. At least initially I plan on going direct to the rear end as is. If it's a complete sluggish dog then maybe a change is in order. Perhaps in the rear end?
One more thought. I am not to keen to drive this no real protection/no airbags and only a lap belt to crazily. I am just doing this for a little fun and to prove I can.

As for progress, yes I now have the 2-24packs rewired (With the CORECT POLARITY) for the BMS. And all is well. Next Steps:
Charge the Batteries back up to 50%.
Design Iron Frame for the Batteries to mount one in the trunk crossways (frame to frame) and one behind the seats (frame to frame)...
Yet another reason to not get crazy.

jerrykco wrote: ↑Fri Jan 21, 2022 12:03 am Thanks for all the feedback. At least initially I plan on going direct to the rear end as is. If it's a complete sluggish dog then maybe a change is in order. Perhaps in the rear end?
One more thought. I am not to keen to drive this no real protection/no airbags and only a lap belt to crazily. I am just doing this for a little fun and to prove I can.

Sure, keep it simple - try it - if its quick enough then great, if you need some more go-go then you have options.
Change the rear axle ratio - maybe able to find 4:1 - 5:1 gears?
Fit smaller dia tyres?
Or if you want a substantial wheel torque improvement then maybe you could re-purpose a 4x4 low range transfer box - take off the chain for the front axle output and cut/modify the housing - so you are just using the planetary reduction gear set? If 2.5:1 reduction combined with your rear axle ratio should get you somewhere around 9:1 which seems to be where most electric motors work well.

NP231 transfer box

Thanks superv8, I like those ideas. Here in the states there are meetups for DIY's in the Denver metro area and I decided to go to one with the MGB after I mounted the motor, then measured the distance and had the driveshaft made and then installed it.
Lowered the car and tried to move it. Ha ha. Not a chance. Had to raise it up and remove the driveshaft to roll it onto the trailer.

Cool project! I have a '67 MGB that I might convert—the engine currently runs too well to bother!

I'm curious to see what you get for 0-60 times. You're leaving a lot of acceleration on the table, but these were slow cars to begin with, so i don't think you'll lose anything to the stock drivetrain after maybe 40mph.

What's the plan for the batteries? One row in the trunk, one cube in the engine bay?

Hi Tremelune,
Plan is one in trunk and one behind the seats. both welded to the frame cross ways.

Any help would be appreciated.
I have hit a snag using the pack sniffer 2 from Woftronix.
The new 24 pack I built was put on a purchased 24 pack buss bar.
I used the existing 12 pack wiring to figure out how to rewire the new 24 pack to match the sense wiring of the two 12 packs.
However, When I do the initial power on of the PS2 it gives the following sequence.
As you can see in step 7 and 8. those readings indicate something is amiss.

I have awesome news! My battery pack is working and WolfTronix PS2 is working also. I was at v1.0. Wolf made a change at v1.2 that fixed a timing glitch. I upgraded to v1.2 and everything is now working. So, my rewire job for the 24 pack sense wires in my rebuilt 2ed 24 pack to match the two 12 packs is 100% working. Whew! Really good news. I still want to also get the STM32F1 for Johannes' "car" code. I'll need a digital canbus speedometer!

I'm really curious what capacity level is left in your pack from Battery Hookup? I've found it VERY hit or miss buying used cells from them, and I'd like to use them in the future IF I can feel like I'm not throwing my money away. A good deal is very tempting, until you feel like your money would be better put to use buying NEW cells.
Thanks!

sigdigits wrote: ↑Thu Mar 24, 2022 5:45 pm I'm really curious what capacity level is left in your pack from Battery Hookup? I've found it VERY hit or miss buying used cells from them, and I'd like to use them in the future IF I can feel like I'm not throwing my money away. A good deal is very tempting, until you feel like your money would be better put to use buying NEW cells.
Thanks!

96%. The Leaf battery pack was a replacement pack (Ready to install in a Leaf) from the manufacturer and was in storage at the depot for the manufacturer here in the USA. It had never been in a car, never charged fully and stored at ~30% charge. I have charged it a couple times, first 35% and now 45%.

jerrykco wrote: ↑Thu Mar 24, 2022 6:17 pm

sigdigits wrote: ↑Thu Mar 24, 2022 5:45 pm I'm really curious what capacity level is left in your pack from Battery Hookup? I've found it VERY hit or miss buying used cells from them, and I'd like to use them in the future IF I can feel like I'm not throwing my money away. A good deal is very tempting, until you feel like your money would be better put to use buying NEW cells.
Thanks!

96%. The Leaf battery pack was a replacement pack (Ready to install in a Leaf) from the manufacturer and was in storage at the depot for the manufacturer here in the USA. It had never been in a car, never charged fully and stored at ~30% charge. I have charged it a couple times, first 35% and now 45%.

You really DID score! BH never seems to have anything like this these days

HI, (I'm back)
After two Spinal Fusion surgeries, followed by a serious back infection at the second surgery site and a third surgery to clean out the wound and now daily antibiotics to suppress reinfection, I am back working on the this MGB project.
Next step install these two 24 cell (2s2P) battery modules into the MGB. Conveniently they will fit cross ways one in the trunk and one behind the seats mounted to the MGB Tubular frame. I am working on the steel mounts. Pictures to follow of the mounts.

Started on the installing of the two 24 pack Leaf batteries in the MGB.
The tubular frame was reinforced to mount the battery packs and now we will check fit and decide on the mounting.
One 24 pack will go behind the seats and one in the trunk.

jerrykco wrote: ↑Tue Sep 26, 2023 3:23 pm HI, (I'm back)
After two Spinal Fusion surgeries, followed by a serious back infection at the second surgery site and a third surgery to clean out the wound and now daily antibiotics to suppress reinfection, ...........

make sure you take Probiotics when you take antibiotics. otherwise all good bacteria in your body is killed by Abtibiotics.

Florastor probiotics can be taken with antibiotics and is not killed by Antibiotics.

No batteries under the hood? I wonder what the corner weights are...

This will be a fun car.

Does anyone know what size cable I should run from the battery to the motor inverter? I was thinking 2/0 to 4/0.
4/0 is $11.00/ft kind of expensive.
2/0 is $6.56/ft
from here in the USA https://www.batterycablesusa.com/extrem ... cable-bulk

There is this chart. But for me the voltage is 365 - 420V

Table of Allowable Amperage for copper conductors 50V or less with 105C rating:
Gauge Amps Outside Amps Inside
of Engine Space of Engine Space
6 120 102
4 160 136
2 210 178
1 245 208
1/0 285 242
2/0 330 280
4/0 445 378

Where are you getting those prices? Buy welding cable.

I used 2/0. I think Nissan used 1/0.

Tremelune wrote: ↑Fri Feb 09, 2024 9:38 pm Where are you getting those prices? Buy welding cable.

That is welding cable.
see link in the Question above.

Well that's interesting...I pid $3.35/ft here a few years ago:

https://weldingsupply.com/cgi-bin/einst ... 304-1330UF

Black cable is currently like $4.50/ft in 2/0...Might still be able to save a couple bucks by buying orange tape instead to mark it!

Tremelune wrote: ↑Fri Feb 09, 2024 10:31 pm Black cable is currently like $4.50/ft in 2/0...Might still be able to save a couple bucks by buying orange tape instead to mark it!

I was planning on using orange split tubing. So that plus sonme orange tape like you suggest should save me a bunch.
Thanks!