I’m finishing my latest Gem project and need to decide which motor to run . The big 3 motors are the G.E 7hp , Advanced 7hp (8 brush) and the 7.5hp Rife 4 fun . I have ran all 3 motors but never in the same Gem or with the same battery pack . So i decided to do a comparison of all 3 in my new Gem . Into the parts closet I go .
The Gem is a 2014 e4 with 1,000 miles on it . It has a 10.35 trans , 24.2" tall tires and a 27s Lifepo4 battery bank (about 92v) . With a 5hp GE motor it would easily go over 40mph . I let others drive it so it is limited to 37mph .
With the smaller motor , the controller was set to drop field current at higher rpm to increase power in the upper rpm range . With these larger motors I slightly increased minimum field current at high rpm . This drops the armature current which will increase torque and consume less power . My number one goal is fast acceleration . With the large diameter tires and low gear ratio to over come , this thing needs lots of torque to get the acceleration i’m looking for .
The R4F motor weighs 46lbs , The GE 7hp weighs 57 and the Advanced 8 brush weighs a hefty 65lbs . One thing for sure my back is going to hate me when this is over
The first motor up will be the R4F , then Advance , then GE . The GE has to go back to Rodney for some additional repairs . So this one wont test until next week .
I’m Intrested to know what kind of amps each motor draws. Can I ask you to
Do a test?
On a stretch of road (one that has a slight hill) could you get you car up to 30Mph and note the Amp draw each motor requires to pull you to and maintain 30 mph or any speed you choose?
If you want to add one to make the group complete. I have a RFF Black motor, by AMD that I blessed and have been running on my cart for the past year. These motors have a bad reputation and have pretty much been warranted out by Polaris with the Blue D&D. IMHO it is the strongest performance motor. My modifications make it as reliable as the Blue motor. It is NOT for sale.
I currently have a super condition 7 HP GE , a T4 still in the box and a fresh Zivan with 7day restart in stock.
SO far i have tested the R4F and the advanced motor . The R4F is the lightest motor . It performed well , Does not have a lot of low end torque but seems to rev a little easier to higher rpm’s . The Advance motor has more bottom end torque but it seems to take a little longer to hit top speed . The advance motor is much quieter then the R4F motor . All 3 of these motors are used but Rodney has went thru all 3 . For me the R4F whines too much . I took all of the regen out and it helped some but the whine is noticeable on acceleration and deceleration . Think of the R4f as a turbo 4cyl and the Big Advance motor as a v8 .
Okay okay, I have been a little busy and didn’t finish this thread. But as a bonus for waiting, you get a review on a 4th motor. My Gem was upgraded to a 96v ,15kw battery. I have been running these motors for a while now and have good experience with them.
The GE 7hp. This motor is strong, very close to the Advance 7hp but quicker. A little less refined but super fun to drive. Quiet and strong. V8 pulling force. I really like this motor.
The 4th motor is the D&D 7hp long motor.( D&D makes the 7.5 for Ride4fun, it is the short motor designed for 2000-2004 gems) This motor is the long motor like the GE and Advance. It weighs a whooping 68 lbs, Its heavy. D&D makes 2 versions of the big motor.
The “68” is the high torque motor, pulls hard but will not rev high. Max speed is in the 25mph range. This motor uses less power then the others and was designed for work trucks. @grantwest used one for a while. The other motor they make is the “69”. This is what I tested, Higher revving motor. It is much stronger than it’s “little blue brother”. Accelerates pretty well but seems to have a little less power on the top end than GE or ADV. Smooth as hell and makes this cool, EV like, sound on acceleration. @RS_E6 ran one of these @96v in an E6. Ran great until he decided to run it down hill at warp 9. The only guy who found a way to break one. Nice job Roman your the man!
Final thoughts. There are different ways to rate electric motors. Anyone of these motors could be rated to 10hp if the manufacture wanted. This is why the small Ride4fun motor can say 7.5 hp, when it’s big brother is 7hp. The R4F 7.5 was the smallest of the 4 and had the least power. It revs well and has that big" turbo whine" @Old_Houseboater says the short 5hp GE motors that came in these years are not good and not even worth fixing when they break. So The R4F motor would be a good upgrade(FYI do not use them in a 6 passenger)
Now the other three 7hp motors were close. I would run any of them and be happy. The “69” D&D was a little slower that the others so I would put it in a close 3rd place. Note, it is a sealed motor and I would recommend it to anyone that lives close to saltwater. I believe this motor would hold up better.
Now down to the last 2, really close. But for me the GE 7 is the top pick. In realty if tested side by side, 1/3 of people would pick the GE , 1/3 the Advance and 1/3 wouldn’t notice any difference. Now off to search for someone to build me a custom 10hp motor!
I know this thread is old. My ride 4 fun motor burnt up. I have a 2002 gem and was getting 35 mph out of it before the burn up. What motor would be a good replacement. From reading here I need the shorter motor. I still would like to get 35 mph. I assume I have an upgraded controller. I bought the car with the motor and updated controller already there. Any suggestions? Thanks in advance.
IMO for your case, stick with what works. Get another R$F blue or the D&D Motor Systems speed motor which is what R$F is actually selling you.
The blue motors are high RPM motors. They work well for the 00-04 years. And some 05’s with the 10:35 diffs to replace the short GE motors.
You can’t fit the long GE or other long motors without moving shock mounting points around and the GEs aren’t as fast turning as the blues. The AMD black is overkill for your uses based on what you posted in other threads.
I wouldn’t call your controller upgraded, so much as it had some parameters changed to allow a higher top speed and maybe a few other settings.
Get in touch with @Old_Houseboater about a refurbished motor. He does good work and you’ll save some coin.
Second on @Old_Houseboater . Maybe even send him your motor to see if he can rebuild it. I found pirateship.com has discounted shipping rate. I was able to send him a gearbox for around $60 from San Diego.
