2000 SAN - How to get GPS Perfect Pass to Hold Speed Better with Extra Weight in Boat

[jhamrick]

I've got a 2000 Super Air loaded down pretty heavy. Perfect Pass Pro Series (see attached pic) was installed maybe 2011 or 2012 I think. In order to get cruise control to hold, what I end up having to do is to get the speed a mph or two over where i have cruise control set. Then, I back off on the throttle but, to prevent the speed from dropping below the set point, I have to give it a bit more throttle as the speed is decreasing to the point where it slowly drops down to the set point. Otherwise, it drops too far and won't get back up to the set point.

If there's less weight in the boat, obviously the speed holds better and this is not as much of an issue. But, I definitely want the weight in the boat to increase the wake size.

So, is there anything I can do to make it less sensitive and more quickly get set on the speed I want without having to decrease ballast? Would changing the prop help at all? Is there something with the perfect pass I can adjust? Something else I'm overlooking? I know I can increase or decrease the KDW on the Perfect Pass but I'm not sure if that effects anything?

Any comments are much appreciated !

[swatguy]

To my knowledge that is not GPS based its paddle wheel based . Stargazer is the only gps based system I am aware of from perfect pass.


With that in mind there are two settings you need to dial in for the weight configuration you run. KDW is the amount of “juice “ the system will tell the boat to give for speed adjustments , the more weight you run the higher the KDW. The fact that it holds speed better when weighted less means your KDW is too low for the weight you are running. If you’re running around 2k-3k you’re KDW should be 160-200 on average.

The next adjustment pertains to the paddle wheel. It’s the NN value. That value is how many rotations of the paddle wheel the system tracks before it makes its adjustment on speed. If you’re NN is too low the boat will surge and hunt quite a bit for speed. And you’ll feel like you’re constantly speeding up and slowing down . If you’re NN is too high the boat will be slow to respond and fluctuate more through the speed. I believe factory setting for NN is 50. Bump that to 65 Heavily weighted boats need a bit higher NN value.


When adjusting the KDW go in 10 increments. It’s a process
similar with the NN. While it may not seem like an immediate difference it’s good to go slowly through the adjustments and take your time and get it dialed. Adjust 1 value at a time KDW or NN. Not both at once. It gives you a more true reading of each adjustment and it’s effect.



http://perfectpass.com/?q=manuals

[jhamrick]

Swatguy, really appreciate the response. Forgive the ignorance, though, I don't think my boat even uses paddle wheel. Am I wrong about that?

[MTRBTR]

Changing the prop will help if the rpms are pretty low at the speed you want.

[rbalan]

If you installed stargazer PP, there is no paddle wheel. If you updated PP to stargazer you would have a paddle wheel. Definitely adjust the KDW in small increments as said, it can make a big difference. Repropping may be the ticket if you aren't getting good results. If it takes a real long time to get on plane when weighted, I would consider repropping anyway. Is this for surfing or boarding?

[jhamrick]

Thanks guys about the prop suggestion. Boat is for wake boarding; not surfing. Any suggestions on what prop to use? Pitch and all that?

[rbalan]

First check and see what your prop is, how much ballast and crew are you running? I have a different boat so I can't comment from experience, but I'm sure someone will chime in.

[brit_hunsicker]

I’m assuming you have the GT-40? The Acme 1616 is a great prop for your boat. That’s what I put on mine and it is a night and day difference from stock. I too was having the same issues with not being able to hold speed. I first messed with the KDW and it helped but not tremendously. I was also having issues getting on plane with heavy weight before the prop change. I run about 2,000 lbs of ballast and with 3-5 people in the boat it still performs well with the 1616 prop. I’m at roughly 1,500 ft of elevation. If you’re at a much higher elevation or run a lot more weight I would suggest the Acme 2570.


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[swatguy]

Your perfect pass most likely has a paddlewheel. Again unless someone upgraded yours with an aftermarket gps plug in .

if you look underneath the boat you should see it just off the center line opposite engine raw water pick up . While the factory Speedo uses pitot tubes(no paddle wheel) , the perfect pass should have a paddlewheel to get it’s signal from during that year( again unless you upgraded to stargazer it added an aftermarket plug in like nautilogic) . Inspect the paddle wheel itself. Make sure all the fins are on it and it spins freely. If you can’t get under your boat you should be able to pull it from inside the boat. It’s a black plastic cone shaped housing . Take note. The arrow should point towards the bow and be straight for the best performance .

The 1616 is where’d id be on the prop depending on what weight you’re running

[OREGON85]

My display looks exactly like that. I have no paddle wheel, but under my dash is the Stargazer system. I have a bit of trouble holding speeds in tight canyons, presumably because it affects the GPS signal. It just reacts slower. This is on a 2000 Air Nautique, the system was installed in 2007.

[funkster]

Like others have said I would start with checking the KDW. If that works, your done. If not, next I would check your linkage to see if it is binding or getting caught on something. If that is free and working properly, I would then check your servo. You can perform a test following this video. I was having a similar problem and then eventually it wouldn’t hold speed at all. My servo was seized up and needed full replacement. However, if you can get your boat to hold a speed, maybe you just have to clean the servo motor. PP also has a how to video on how to clean your servo motor.




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[jhamrick]

Thanks all for the replies.

1. I'm pretty sure my boat does not have paddle wheel (anymore at least); just GPS.
2. I've got 2750 - 3000 pounds at least of weight in the boat - any particular KDW work best or just keep toying with it?
3. For the prop, please see the attached pic. I think this is an ACME prop but it's a bit difficult to make out the numbers: 1-888-661. I'm not sure what prop this is? Anyone know? Would upgrading this prop really make a difference? ACME website is telling me, based on altitude, weight amount in boat and wake size, that either a 1630 or a 1578 would be ideal but I dunno.

Anymore thoughts?

Really appreciate the responses!

[swatguy]

The prop is actually stamped the the end with the nut , so those are the numbers we need. It will have a number stamped and then dimensions. The numbers you show on the back in the pic are just the acme phone number .

Its possible you don’t have a paddle wheel, it woulda been an upgrade offered down the road when god became more widely used.


kdw with 3k should be around 200. Give or take.

[MTRBTR]

Let’s take bets. I’m guessing the old one is a 644. And I would agree with those two props you mentioned for how you use your boat.

[jhamrick]

So dumb me, it occurred to me to go back through old emails to see if I could find anything. In 2012, a friend of mine wrecked my prop and bought me a new one. This is what he said in 2012 about the most current prop I have on my boat

"I ordered an ACME 1248 prop - 13.5" diameter, with 16" pitch. This is same pitch as factory, but 1/4 inch larger in diameter, with 4 blades. They tell me it will hold speed better than the factory prop, and will not change the engine rpm. They also told me that an ACME 1464 prop will get you up faster, but it will make the engine run 500 rpm faster. If you want a different prop in the future, that's the one to try - but use with caution."

Thoughts?