3.5 vs 5 hp and dana 8.9

GEM Forum
1

hey guys I just picked up 2 motors one is a stock 3.5 and the other is a 5hp
is there any benefit to the 5 hp? speed torque? the 5hp has an extra black plug coming from the brush area of motor with oblong plug What is this for`?
Also the 5hp spins at approx 500 less rpm than the 3.5

I use my truck version for utility use and although speed is fun torque often is needed more than speed I am currently using a 8.9 gear and think I’d be better off with the 10,9 or 12 how much speed will a sacrifice using the lower gear ratios

2

5HP will give more torque. Speed is a function of the programming. Gear ratio - Tire diameter etc.

Speed is limited by how fast you can turn the motor without having it “Grenade”

3.5 motor is rated for 4500 Rpm 5 motor is rated for 4100 Both motors will live at 5000 Rpm

Since you have a truck you would be happier with a 10.35 or a 12.44
If your on flat ground go with the 10.35 if in hilly go with a 12,44.

You have the 5HP long motor which is from the later model carts. the extra wires are for a thermal sensor. You don’t have to use it

List your tire diameter and gear ratio and I wll tell you your Motor RPM at 25, 30 and 40MPH

Rodney

3

[quote=OLD HOUSEBOATER;27798]5HP will give more torque. Speed is a function of the programming. Gear ratio - Tire diameter etc.

Speed is limited by how fast you can turn the motor without having it “Grenade”

3.5 motor is rated for 4500 Rpm 5 motor is rated for 4100 Both motors will live at 5000 Rpm

Since you have a truck you would be happier with a 10.35 or a 12.44
If your on flat ground go with the 10.35 if in hilly go with a 12,44.

You have the 5HP long motor which is from the later model carts. the extra wires are for a thermal sensor. You don’t have to use it

List your tire diameter and gear ratio and I wll tell you your Motor RPM at 25, 30 and 40MPH

Rodney[/quote]
14x23 is tire size

4

…25MPH … 30MPH

8.9 - …3253 …3904

10.35 - …3783 …4540

12,44 - …4547 … 5456

If your on flat ground you have the long 5 which is pretty strong. Pop it on your 8.9 gear box.,

Set function 1 (MPH scaling) to 23 - Set function 7 (min field current) to 62 - Set function 20 (MPH limit) to 32

The cart should do pretty with those settings, if you easy foot it when you have 4 aboard.
,
Let us know how it works out

Rodney

5

I already had this typed out before it was answered, so I’ll post it for future reference.:o

23"D X pi = 72.26" circ. = 6.2’ cir

5280ft/mile / 6.02circ= 877rp mile

motor 8.9 times as fast = 7805 motor rotations per hour

25mph = 195,133 motor rotations per 25 miles (in 1 hour)

195,133 / 60 = 3,252 rotations per minute (RPM)

6

Dave

I sent you my spread sheet by email

All you have to do is enter the tire diameter

Rodney

7

Thank you,
Now what will I do to stay awake? :smiley:

8

if u decide to sell the 3.5 hp motor , please let me know.

9

I’ve got a short 5 and a 7 surplus

10

Rodney,

what are “short 5” motors ? did they make different length 5’s ?

11

Short 5 was used thru 2004.

Long 5 starting in 2005 - has overheat sensor.

12

[quote=SCOUT202;27797]hey guys I just picked up 2 motors one is a stock 3.5 and the other is a 5hp
is there any benefit to the 5 hp? speed torque? the 5hp has an extra black plug coming from the brush area of motor with oblong plug What is this for`?
Also the 5hp spins at approx 500 less rpm than the 3.5

I use my truck version for utility use and although speed is fun torque often is needed more than speed I am currently using a 8.9 gear and think I’d be better off with the 10,9 or 12 how much speed will a sacrifice using the lower gear ratios[/quote]

Rodney,
I received my used controller from Arizona and installed it i replaced my 3.5 with the other 3.5 both ohmed out fine. I have 6 brand new battery’s i tested voltage into the controller it is 75.9 the large contactor is engaging. When pedal is depressed motor whines but no rotation. tried a different motor with same result> I’m stumped any suggestions?

13

Bad controller

14

are there any voltage readings out of bottom of controller when pedal depressed? should voltage start low and progress to high at full throtle?

15

Make sure you have field wires on field and armature wires on armature.

As the field current changes the armature current increases.

16

did some voltage checks at motor key on or off readings are the same
A-1 to ground 40.0 volts
A-2 to ground 40.0 volts
F-1 to ground 33.6 volts
F-2 to ground 33.7 volts
Key on forward gear pedal depressed engages large relay and motor does nothing whine coming from controller.

17

The 72v supply is not grounded, so checks to ground aren’t helpful.

18

OH would know more, but an analog voltmeter should read F and A voltages…

A to A and F to F.