# GEM won't go over 29 mph **URL:** \ **Category:** GEM Forum\ **Created:** [February 27, 2016, 10:55am UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804 "2016-02-27T10:55:43Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Old\_Houseboater](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/old_houseboater/32/544_2.png) [@Old\_Houseboater](https://community.electricforum.com/u/Old_Houseboater)\ **Post date:** [February 28, 2016, 8:04pm UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/41 "2016-02-28T20:04:56Z")
Dave I don’t think he cares about RPM. He just wants to see the GPS read over 29 MPH. You and I want to see the GPS read over 29 MPH Once we get this problem solved we can go back and refine the settings to give the best performance/longevity balance for the motor he has. Right now we have settings strong enough for a R4F motor to get to 40 MPH. I have a small quirk, I don’t give up ---
**Author:** ![spider445](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spider445](https://community.electricforum.com/u/spider445)\ **Post date:** [February 29, 2016, 10:39am UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/42 "2016-02-29T10:39:09Z")
Well completed another test using the MM, this one is the adjustable MM and was set to read actual speed up to 22mph then switch to half speed. Reading went to 22 MPH on speedo and then went to 13/14 with GPS reading 27/28 mph. Then adjusted it up 2 turns, speedo read 24/25 and didn’t switch with GPS reading 28/29. Removed the MM and speedo went to 25/26 flashing with a top speed of 29 mph on GPS. So I did not get any additional speed by using the MM, which also relates to controller programing changes having very little effect on speed. The major increase came from using the taller tires. The T3 controller must have some type of built in limiter preventing a speed increase of more that 29 mph. At this point I’m not sure that even changing to a RFF motor, would make it go any faster based on the T3 controller settings. Would be nice to know if position #7 could be changed. Thanks for all your help guys. Greg ---
**Author:** ![Old\_Houseboater](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/old_houseboater/32/544_2.png) [@Old\_Houseboater](https://community.electricforum.com/u/Old_Houseboater)\ **Post date:** [February 29, 2016, 11:30am UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/43 "2016-02-29T11:30:47Z")
Manual says 5,6,7,and 8 are unused However 4 seems to show up in most T3 read outs. What the hell change the 4 to 3 or 5 and see if it does anything. Looks like KingHappy has the skinnys. Dave have you got field weakening figured out? ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [February 29, 2016, 11:37am UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/44 "2016-02-29T11:37:56Z")
No, see my new thread. I value any input. I have zero experience changing settings. What about the other field settings? ---
**Author:** ![LithiumGods](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/lithiumgods/32/672_2.png) [@LithiumGods](https://community.electricforum.com/u/LithiumGods)\ **Post date:** [February 29, 2016, 5:54pm UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/45 "2016-02-29T17:54:41Z")
greg, if Dave has an external device that well lower field weakening , that should work for you . if he could make you a device to drop it down by 75% you should see a top speed improvement . p.s. a RFF motor is completely different from a stock motor , even with the same controller setting you should see a higher speed . but I have not tested it that way . ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [February 29, 2016, 6:33pm UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/46 "2016-02-29T18:33:47Z")
I can do that. To make something safe to let out of my control is another matter. Right now I have 72v at the switch. If Rodney had a T3 to play with, I would trust him with it. I already helped him fry a controller. He can take a punch!😃 If I was in a “Gem” area, I’d just buy a 2005 for testing. ---
**Author:** ![LithiumGods](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/lithiumgods/32/672_2.png) [@LithiumGods](https://community.electricforum.com/u/LithiumGods)\ **Post date:** [February 29, 2016, 6:45pm UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/47 "2016-02-29T18:45:38Z")
[quote=Inwo;29294]I can do that. To make something safe to let out of my control is another matter. Right now I have 72v at the switch. If Rodney had a T3 to play with, I would trust him with it. I already helped him fry a controller. He can take a punch!😃 If I was in a “Gem” area, I’d just buy a 2005 for testing.[/quote] come on you have to give us a little more info on the fried controller ---
**Author:** ![LithiumGods](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/lithiumgods/32/672_2.png) [@LithiumGods](https://community.electricforum.com/u/LithiumGods)\ **Post date:** [February 29, 2016, 6:46pm UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/48 "2016-02-29T18:46:59Z")
also cant you just swap out a t3 for a t4 in a cart ? ---
**Author:** ![Old\_Houseboater](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/old_houseboater/32/544_2.png) [@Old\_Houseboater](https://community.electricforum.com/u/Old_Houseboater)\ **Post date:** [March 1, 2016, 6:13am UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/49 "2016-03-01T06:13:01Z")
This would be the way to go. HOWEVER: It would be an expensive fix for a project that has only 5 HP and when complete will end up at no more than 32 MPH due to not wanting to burn up the motor. The thing here is that we have an unusual problem that we have come up with that HAS TO BE SOLVED so the people involved can sleep at night.😃 > [@kinghappy;29297](#): > > also cant you just swap out a t3 for a t4 in a cart ? ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [March 1, 2016, 6:44am UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/50 "2016-03-01T06:44:58Z")
> [@kinghappy;29296](#): > > come on you have to give us a little more info on the fried controller Nothing to do with MM. Just a slip of a test probe.🙂 ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [March 1, 2016, 6:45am UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/51 "2016-03-01T06:45:58Z")
[quote=OLD HOUSEBOATER;29301]This would be the way to go. HOWEVER: It would be an expensive fix for a project that has only 5 HP and when complete will end up at no more than 32 MPH due to not wanting to burn up the motor. The thing here is that we have an unusual problem that we have come up with that HAS TO BE SOLVED so the people involved can sleep at night.:D[/quote] I suppose we could find a T3 to test if they swap. ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [March 1, 2016, 6:49am UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/52 "2016-03-01T06:49:02Z")
Testing on hold in Minnesota…:rain:😃 ---
**Author:** ![LithiumGods](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/lithiumgods/32/672_2.png) [@LithiumGods](https://community.electricforum.com/u/LithiumGods)\ **Post date:** [March 1, 2016, 7:04am UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/53 "2016-03-01T07:04:32Z")
does anyone know if a t4 can be swapped in for a t3 ? ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [March 1, 2016, 8:50am UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/54 "2016-03-01T08:50:08Z")
Are the dash displays the same? The T4 is connected to p23. Tx data may not be the same. I expect it is.🙂 ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [March 1, 2016, 1:30pm UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/55 "2016-03-01T13:30:10Z")
[quote=Inwo;29238]That is exactly how they should work. Just a more convenient fix than magnet change. Hope to learn from this!😕[/quote] [quote=OLD HOUSEBOATER;29247]Dave this is really interesting. Refer to the spread sheet I sent you on tire diameter and plug in 23 inch tire. Look in the 10.35 row. then read the 30 mph column. About 4540 RPM then look up the same RPM in the 12.44 Row. Gregs real world results track perfectly. The control limits RPM to somewhere south of 4500 RPM Greg Try The MM again I believe we GOT IT Rodney[/quote] Finally looked at spread sheet .😕 Don’t follow the math. Remember we are not actually changing gears. Just telling the controller to make the computations of spread sheet. If the controller was set to limit at 4500rpm, speedometer should read 25mph. Set to 12. If set to 10 then 30mph at 4500 rpm. Which would be over mph limit. Now let me think another way.😕 Say, RPM is limited to 3700 internally. That seems to make sense. :clap2: No effect when 10/1. As it can reach 25 on speedometer. But when speedometer is set to compute 12/1, speedometer can only go to 22mph. As it hits 3700 RPM limit. Is this another way of saying what you are thinking? ---
**Author:** ![Old\_Houseboater](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/old_houseboater/32/544_2.png) [@Old\_Houseboater](https://community.electricforum.com/u/Old_Houseboater)\ **Post date:** [March 1, 2016, 2:04pm UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/56 "2016-03-01T14:04:56Z")
Not at all. Just trying to use the speed limiter to keep the speed within the motor limits when the MM is installed. I don’t know if it will work. If it does you can have hotter programming for better performance at less than the limited speed. ---
**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\ **Post date:** [March 1, 2016, 2:33pm UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/57 "2016-03-01T14:33:52Z")
Limit is set to 3700 if there is one. Make sense? ---
**Author:** ![Old\_Houseboater](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/old_houseboater/32/544_2.png) [@Old\_Houseboater](https://community.electricforum.com/u/Old_Houseboater)\ **Post date:** [March 1, 2016, 4:24pm UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/58 "2016-03-01T16:24:02Z")
Yep, that’s the truth:eek: ---
**Author:** ![spider445](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spider445](https://community.electricforum.com/u/spider445)\ **Post date:** [March 2, 2016, 12:22pm UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/59 "2016-03-02T12:22:03Z")
Well conducted another test today with some additional that might help, but still didn’t get over 29 mph. Fresh charge on batteries. Changed the following settings; #4 from 235 to 208. #8 from 255 to 235. #9 from 218 to 100. #10 from 170 to 80 Speedo went to 25/26 flashing and GPS read 29 mph but no faster, car didn’t feel as quick but did get to the max speed of 29 mph, so something in the controller must be causing it to not go over 29mph. Also sent a message to RFF re my issue and was advised that I would just have to let them know the motor was for a 2005 wit T3 so they could send me the correct motor? Also I should get about 40 mph using the RFF motor. Thanks for your help! Greg ---
**Author:** ![LithiumGods](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/lithiumgods/32/672_2.png) [@LithiumGods](https://community.electricforum.com/u/LithiumGods)\ **Post date:** [March 2, 2016, 12:42pm UTC](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804/60 "2016-03-02T12:42:45Z")
greg can you keep the same parameters and and just drop #13 down 10 points from where it is ? with the above you might pick up 2 more . don’t change anything else. [Previous page](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804.md?page=2) [Next page](https://community.electricforum.com/t/gem-wont-go-over-29-mph/5804.md?page=4)