High Speed 9.3 Transmission coming soon

The other day I decided I wanna try out the 9.3 Gears in my High Voltage Hotrod. Right now I have the 12:35 Transmission with 24.7 inch tall tires. I have the 8kw AC motor & a 24c Goliath Battery. Right now the car tops out at 57-58 Mph.

I have a spare transmission laying around and Figured I would send it to Rodney & get him to install some 9.3 gears in it and take a look around inside while it’s open make sure everything is A-ok”

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That gearbox looks easier than the legacy gearboxes.
It splits in half rather than dumping all the contents out the bottom.

Gabe is sending the 6:1 to Scott.
Ha ha! :grinning:

I had a classic 10.35 with welded plates 8kW and 25s tesla before going back to OEM. drove only once over 60mph and I got scared

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Because you did not have sway bars…

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I have no doors either so it feels faster.

I also had the 10.1 gears, 8kw, 25s Tesla battery for awhile. Ran 64mph but really struggled on acceleration and on the hills. Could not maintain speed up a grade with just one person in the car.
Good luck grant, maybe the SF hills have gotten flatter. :slight_smile:

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We have the flattest hills in FL :rofl:

Tbh I built it only because I didn’t know what I was doing or what would be the result. I was only focusing on “I want the fastest one” but then I’ve noticed that Acceleration is funnier than top speed and that I didnt wanna get crushed in a tuna can on wheels lol

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Not too long ago- a wise forum member put it into ultimate perspective
I think I will have this engraved and put above my workbench.

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Hey Gabe I would like to hear more about your high speed transmission.

Classic Gems had a few gear options

R4F sold a 6:1 (high speed gears) that would go in a Classic Spicer transmission
Then you had a Factory 9.8 gears in the early gems
Then you had 10:35 in 2002-2005 cars
Then they went to 12:35 in 05-15
Some Trucks & E6 cars had a 14:1 (cars that were to carry a Heavy payload)

Then we jump to the New (Team Brand) transmissions that have a factory 17:1 raito
R4F sells 9:3 or 12:35

My personal opinion is my car could Turn a 10:35 all day long. Zero issues! Think about it
My classic Gem had a 10:35 with a D&D 7.5 Hp
DC motor. It went up any hill I threw at it.

Fast forward to Now. I have the Big AC motor and 24 cell in my car it “should be” able to spin what my 7.5 HP D&D or R4F blue motor did all day long. Mike perhaps your car was not programed right or somthing was wrong, cause I never heard of your car not being able to make it up any hill all we were told was how fast your car was?

Now If a 10:35 was available I would jump on that gear raito because personally I think that’s the best gear raito gem has! But that’s not an option. I only have 9.3 to go with in my stock transmission. With that said yes I’m taking a risk and going with a Gear raito I’m not 100% sure will work out in my Steep community. I do think “hills can be hacked” with driving technique
(Example) a 9.3 might fly up a hill with a running start. But a 9.3 might not make it up the same hill if your car is loaded and you stop mid hill and try and start again. So it might not be for everyone I understand. I guess I have 3 options

  1. It might work out fine
  2. It might not work and I have to return to 12:35
  3. It might not work and I switch over to PMAC.

Hey Grant, mine was a classic gearbox with welded plates on its sides so it can be bolted in a 2016+ 1 of 2 that Rodney built. If you wanna give it a try lmk

I’m looking for a 13.1 to combine with Repro to see if I can make an oem one go 50+ mph

Love that idea! 12.1 with tall tires/wheels is right at 48 as you know.

Yes this is the idea

Pmac and 6:1 would be the option but it’s untested, I have Dave’s legacy one with welded plates I’m sending to scott I think.

I also have pmac motors and S6 a with mating dcf so it should work but again we all know that Sevcon is never straight forward

There was a reason I couldn’t use it. I think was a drive by CAN dld and wouldn’t mate with another dld.
I have good running pmac files though.
Maybe it will run wireless in a new gem.

@djgabriel2004 are your shafts correct length? I would like to send samples to china to be copied.

Mike kc lets all hear about the 10:35 that you HAD that could not hold speed on a hill with a single person inside! OR Is this Place (electric forum) where we share or spread info or LIKE (Facebook)” total bill ■■■■”where we share and spread mis information.

Not mis- info if it’s a report.

I could make it up hills but could not hold speed, if I was running 50 at the start of a grade (and not a steep one) I would be doing 45 at the top, foot to the floor. The issue obviously gets worse with more weight in the car, one, two, three, or four people. It was not like it was undrivable but it was noticeable.
It could very well be in the DCF and not applying enough torque, We see so few 10.1 setups that I did not mess will tuning the DCF, just went back to 12.1. Also, my 10.1 gears have something wrong with them. Super high-pitched whine above 30mph, that was unbearable and had to go. The gears have about 50 miles on them… :frowning:
You stated that your thought that 10.1 gears were perfect, I am in the camp of 12.1 being perfect for flats and hills.

I guess we will find out.
Grant, do you know if you are holding 9k rpm?
If not, maxed out on torque, and higher gears can’t add speed. Imo
Although efficiency may be better at lower rpm. It think efficiency is best at rated volts and rpm.
Rpm goes up with voltage, so im guessing about twice the rated rpm is a good place to be.
Anyone have nameplate data handy?