How to get maximum output from a Jag?

[Thundrio]

We are using bicycle wheels on our robot this year (ironically to make crossing the barrier easy), but we are having difficulty crossing a replica of the barrier in the center of the field. When we apply full forward using RobotDrive() (java, arcade drive, 4 motors), it gets the front wheels over the ramp and cuts out when the bottom ones hit the ramp.
We are using 4 black Jaguars updated to firmware 101 and connected with pwm connections. Our mechanical lead has done the math and says the four cim motors we are using should be able to output more power/torque(not sure if I'm using the right word) than we are getting. One of our mentors believes this is because we need to ramp up the speed over a period of time, which should let it cross the barrier. We tried switching the jaguars to automatic ramp mode, which did not help anything. Afterwards we reset it back to manual ramp and using bdc-comm tried to set the ramp values on the jags to 1000, but realized the value reset to 0 when the robot was powercycled (and after we manually changed the values, my code couldn't move the jags until after a powercycle)
Now the mentor believes that it is something in the RobotDrive/Jaguar wpilibj code (which I showed him) that is causing the ramp rate to reset, or to cause the robotdrive to not give the maximum output. As programming lead I explained that the jaguar will only accept values from -1 to 1, and by my understanding full forward sends the maximum output (I tested this by making a button that when pushed sent a value of 1/-1 to all of the Jaguars, which gave the same effect as full forward). My question is are we actually able to get more out of the Jaguars than just using RobotDrive() (without using encoders/CAN/PID loops), and if so how.
Also a quick wpilibj question if anyone can answer. I proved that I was sending the maximum value to the Jaguars by assigning them to a button and outputting the resulting speed using .get(). however I do not know how to read the Jaguars values when using robotdrive (if this is possible). When I create Jaguar objects that are assigned to the same ports as specified in RobotDrive, it will not run.

Any help on this would be great.

tyvmia