The BIG motor Shootout . Which of the high Hp Motors is the best?

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 :sob:


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 .

Watching! :grinning:

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?

Very interesting test. Can’t wait to see your “best in show”.


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.

Mikes black motor is a Advanced motor so he has what your talking about. I’m afraid what you would want for the GE 7hp.

Any updates? Like to hear your test results, I might be in for a new motor… :frowning:

1 Like

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 .

Hope to get to the GE motor this week .

I was poking around on the r4f website and saw this which made me laugh after reading your post “hear “Turbo Whistle” of Ride-4-Fun Motor”

It’s not a whine… it’s the turbo kicking in!