General questions concerning Perfect Pass

[Tbub]

I like to know how things work. That being said, I need to stop tweaking PP, but just a few question that I am sure folks on this forum can easily answer. I have been using Classic Mode for a while and like it, seems a bit easier. Classic Mode is RPM based so why would crew weight and skier weight make a difference? Doesn't PP just try to maintain that RPM? Also, to get times in Classic you still have to autocal the system then map the course, correct? Using Classic I am getting an entrance gate beep and a beep at each ball so it is using GPS for that, right? Sorry for all of the questions but I am certain you guys have all the answers. Thanks so much. Tom

[Jmoski]

Which version of PP do you have? The more crew weight you have, the more water the hull is displacing, hence you will need higher rpm to achieve the same speed due to the extra drag on the hull.

[Tbub]

StarGazer Ver. 9.2

[BraceMaker]

Baselines essentially calibrate the system to what rpm is roughly correct for your boat elevation etc. it has algorithms built in for how much response is needed and when. It’s not just saying rpm low speed up rpm high slow down it has dampening and response curves to help it apply the correct amount of input to generate the right amount of throttle change.

 

Imagine I can correct 1000 times a second but our data is revs per minute. How do I rectify the slow data to lots of corrections and how much magnitude do I give? One way would be to apply 100% throttle whenever in the snapshot of rpm data coming in was low and 0% throttle whenever it was high. Another could be every time it’s low we give a bit more throttle until it’s high then we back off. But for a skier where we know load is periodic and magnitude is different for a 200 pound guy short line vs a 100 lb gal at 22 off we want to modify the response so that we’re not chasing the target.

 

 

[BraceMaker]

Z box and zero off add a different layer which are accelerometer ie. Right now the boat is slowing or accelerating. Classic rpm mode doesn’t have that so it extrapolates what it would be.

[skiboyny]

For every lb you add in either skier weight or crew weight the system adds RPM to keep the boat moving at a rate that will make total time. (more weight slower boat) There is a bit of guesswork involved that's why at the end of each pass it shows a rpm add + or - On your other questions Yes the system is using GPS for mapping. When in classic mode it's rpm based, In stargazer mode it's still rpm based but gps is making corrections along the way in terms of speed.

[HMan66]

@Tbub you have to map the course for the gps slalom mode to work properly, but it’s super easy. I just upgraded to 9.2 and the pull is so much better!