Shouldnt this 99 DS be faster after upgrade?

[brotherhay]

Ive built up a 1999 DS series cart pretty nicely. Poppin wheelies with the torque, but it really feels like it should be faster on the top end.

Alltrax 48600 600A controller, with personality switch
all HD components as well as 2G wires.
14"rims/23" tires
New battery pack as of May 2019
Plum Quick Rattlesnake motor (rated to do 29-32mph). Talked to the guy on the phone about the motor when I ordered it. He figured with the tires and controller 32mph was about right.

I cannot get the cart over 27mph on flat blacktop. Ive played with the Alltrax toolkit and made some adjustments, but from what I can tell its set to give 600Amps, and 100% of full throttle. From watching the logging while driving, I could see it was getting 100% throttle, nothing else really stood out.

Does it seem this setup should reach 32mph? Pretty sure Ill have to get some logs from the controller, but dont have a laptop/tablet handy currently.

[WalterM6]

From the web site.

Speed 28-30 mph (estimated) and added 50% more torque *must upgrade controller*, flat terrain and a good quality battery pack.

Maybe you need the HD forward and reverse switch?

[brotherhay]

Oh I got all that. Solenoid, F/R Switch, Cables. I changed the gear oil, replaced with synthetic. New pads and drums

I suspect im just up against a weight issue. Rear seat, HD leaf springs, added accessories. Add a few people on and for sure its going to slow it down on the top end.

Time to really get digging in to the Alltrax settings. Speed and torque curves were set to standard also.

[BBBHC]

What are your RPMs at full throttle? That will tell you how fast your cart should go. You can use this to calculate expected speed: http://www.buggiesgonewild.com/speed-calculator.php, it's found in "Quick Links" in the tool bar.

If I remember right the gear ratio is about 12.3 and you will want to measure your tires for better accuracy.

[Out2Sea]

Remember that the speed calculator does not include rolling or wind resistance. It’s a hypothetical number. Reason Detroit auto makers have wind tunnels and tire makers have rolling resistance ratings.

[scottyb]

The motor would need to reach 5750 rpms for the 23s to reach 32 mph. You may call them and ask if that is possible. You might also save a monitor file and post it here so we can look at other factors like motor amperage draw & battery voltage drop when the cart is at full speed.

[brotherhay]

I should be able to get logs mid-week. I notice on PQs site it has a field map chart of motor type (not including the one I have), and every motor looked to withstand 6500 rpm.

https://plumquick.com/wp-content/upl...-map-chart.jpg

Does the alltrax toolkit 3.8 allow you to adjust the max RPM? Im not sure I saw a setting for that, albeit their manual shows it from the previous version.

I did also notice that my tires are not 23" around, they are more low profile, and are actually 20.5".

[brotherhay]

Time to bump this up since I have fixed a previous issue that was hindering my testing.

I do not see anything in the Alltrax toolkit for my controller that displays RPMs.

I can get a file, but of what. Just save it from the Monitor section? Looks like each tab saves its own config/log files.

[Sergio]

Series motors don't have speed sensors so there is no rpm monitor.

The comment about rpm I think was meant as the mathematical rpm your motor would be rotating given your parameters.

The manufacturer could tell You what kind of torque to expect at that rpm.

This is how You save a log from a test run:

https://alltraxinc.com/wp-content/up...al.pdf#page=29

The things I think are important to look at:

1) What is the Maximum Motor Armature Current and what are the other parameters at that time (Motor Voltage, Battery Voltage and Battery Current)?

2) What is the Maximum Battery Current and what are the other parameters at that time (Motor Voltage, Motor Voltage and Motor Armature Current)?

3) What is the Minimum Battery Voltage and what are the other parameters at that time (Motor Armature Current, Motor Voltage and Motor Armature Current)?

4) What is the Maximum Motor Voltage and what are the other parameters at that time (Motor Armature Current, Battery Voltage and Battery Current)?

That will allow you to determine if the Controller was a limiting factor, the batteries were a limiting factor, the throttle was a limiting factor or the motor was the limiting factor.