openinverter forum

Hi,
Just wondering, given Damian's proof of the ability of the CVTs I'm wanting to plug some gaps in my knowledge before splurging on one of these CVTs so that I can be confident I can run it at the full documented speed.
Anyway.
Given the inverter takes the OEM battery voltage of around 220V or whatever it is and boosts it to 650V, is this still the case when you feed it around 400V via the zombieverter given the boost stage of the inverter is bypassed and it is connected directly to the capacitor bus bars. Essentially does the inverter guarantee the motor gets 650V and can run at its max speed despite the voltage fed into it?

Feel free to correct me anyone, but I think bypassing the boost stage means the inverter can only deliver the same max voltage as the battery. But Damien has said/shown that these gearboxes don't need 650V.

JamesA wrote: ↑Tue Apr 18, 2023 12:35 pm Feel free to correct me anyone, but I think bypassing the boost stage means the inverter can only deliver the same max voltage as the battery. But Damien has said/shown that these gearboxes don't need 650V.

Yes he has said that, the problem is understanding what rpm they then put out at a lower voltage. For my application, the GS300H would need to run full speed (4230rpm out the gearbox), for 85mph is this rpm still achievable at a normal EV voltage (circa 360V in my case). I probably need to buy one and test it but given people are doing this at present I'd like to see if anyone has any experience with this yet.

I haven't been able to find a video of Damian's where he drove with the RPM of MG2 displayed again, but this would be really interesting to see if anyone knows which video.

around 5 -6mins in for motorway speeds.

I'm running a Mercedes B250e battery pack from Tesla with my GS450h transmission. Fully charged, I'm at 352.8 volts. I've only been up to about 80mph on the highway, but power is not a concern.

PatrcioEV-ATX wrote: ↑Tue Apr 18, 2023 5:34 pm I'm running a Mercedes B250e battery pack from Tesla with my GS450h transmission. Fully charged, I'm at 352.8 volts. I've only been up to about 80mph on the highway, but power is not a concern.

Is that in low or high gear on the transmission?

What sort of rpms is mg2 doing for those speeds? Cheers

royhen99 wrote: ↑Tue Apr 18, 2023 2:18 pm
around 5 -6mins in for motorway speeds.

So he doesn't say as far as I have noticed what gear ratio he is in but from a rough calc he must be in the 1.9 ratio to get those speeds at that rpm for mg2. The problem here for me is I'm looking at using the gs300H which outputs at 3.33 so is a lot slower, and his rear diff is 2.8.

Ideally I'd need to be running up to max rpm of 14000 for 85mph or change my rear diff gearing which I believe they don't do any lower that 4.1 for my van (not sure how universal the gears are between makes however....)

The inverter puts out the same voltage as you feed into it. You don't need 650V, it's perfectly usable on 320V ish,

xp677 wrote: ↑Tue Apr 18, 2023 10:56 pm The inverter puts out the same voltage as you feed into it. You don't need 650V, it's perfectly usable on 320V ish,

Thanks, yes I'm aware of that now. I understand that they are usable, I was hoping to be able to understand whether a GS300H would be usable also. Which, if not run at full revs, is not for my purposes as stated in my previous post. The GS450H 2 speed gearbox is really the reason that it can be run on lower voltages as it enables the gearbox to achieve highway speeds at a fraction of its max rpm output.

PatrcioEV-ATX wrote: ↑Tue Apr 18, 2023 5:34 pm I'm running a Mercedes B250e battery pack from Tesla with my GS450h transmission. Fully charged, I'm at 352.8 volts. I've only been up to about 80mph on the highway, but power is not a concern.

What is the max rpm for MG2 with your setup? I'd like to understand what the maximum is with these transmissions in order to know if I can achieve the necessary RPM output for my van. I need to achieve circa 14000rpm with my van for it to be able to drive at motorway speeds, however, given I won't be feeding it 650V and instead will be at around 350V I want to know if this will affect the top speed possible. Is the rpm/volt relationship linear also?

Jacobsmess wrote: ↑Tue May 02, 2023 4:57 pm What is the max rpm for MG2 with your setup? I'd like to understand what the maximum is with these transmissions in order to know if I can achieve the necessary RPM output for my van. I need to achieve circa 14000rpm with my van for it to be able to drive at motorway speeds, however, given I won't be feeding it 650V and instead will be at around 350V I want to know if this will affect the top speed possible. Is the rpm/volt relationship linear also?

I have it limited to 11,000 in the software but have never gotten anywhere close to that. I don't think anyone uses this transmission at much higher RPMs. With my rear diff, I only see ~6,000 MG2 rpm at 90+. I'm thinking of changing out my ring gear to get more torque at low speeds. I don't ever need to go over 90mph. I've done 95mph when the pack was around 300 volts.

PatrcioEV-ATX wrote: ↑Wed May 03, 2023 12:53 pm I have it limited to 11,000 in the software but have never gotten anywhere close to that. I don't think anyone uses this transmission at much higher RPMs. With my rear diff, I only see ~6,000 MG2 rpm at 90+. I'm thinking of changing out my ring gear to get more torque at low speeds. I don't ever need to go over 90mph. I've done 95mph when the pack was around 300 volts.

Thanks, mind sharing your gear ratio and wheel diameter?

Jacobsmess wrote: ↑Wed May 03, 2023 1:20 pm Thanks, mind sharing your gear ratio and wheel diameter?

2.73 and 26.3"

PatrcioEV-ATX wrote: ↑Wed May 03, 2023 6:48 pm 2.73 and 26.3"

Thanks, so you'd be in the 1.9 gear on the transmission. Are you running the original oil pump setup and have you locked the input shaft?

Jacobsmess wrote: ↑Wed May 03, 2023 6:59 pm Thanks, so you'd be in the 1.9 gear on the transmission. Are you running the original oil pump setup and have you locked the input shaft?

Yes to both.