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Ed Obermeier's Stargazer Tuning document


Chef23
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I copied this off BOS after Ed posted it a while back and a few people have been looking for it so here it is.

 

Directions for SG setup.

1) First thing is to MAKE SURE you don't overshoot your baseline rpm on pullup, especially on a short setup. If you overshoot the set baseline (too high rpm) it takes SG longer to settle back down to the right prm than it does to come up to it. Gauge where your throttle handle should end up when you pull up a skier and be consistant about taking the throttle handle to that same exact point every time (as much as possible) so your pullup's are consistant and you're not overthrottling the pullup.

 

2) How quickly your SG engages (locks in) determines how quickly it will settle in to correct speed, which is especially critical on short setups. I have found (and numerous others have confirmed) that LOWERING YOUR BASELINE RPM for each speed will help your SG engage more quickly. On my boat ('05 RLXI, 340 hp Monsoon engine) for 34 mph i.e. I've lowered the BASELINE RPM by about 300 rpm from the OPERATING RPM (in other words rpm the boat is running at at speed) so it's engaging at around 32.5 - 33 mph speed. Again, by not overthrottling on pull up and allowing the SG to engage sooner makes it a smooth transition to correct speed before you hit the entry gate. Overshoot and it's hunting around and won't settle properly before you hit the entry gate; that's where you often end up with a rodeo ride off three ball. Lowering the baseline doesn't affect anything except how early the system locks in. You want it to lock in before it gets up to speed but not too far ahead. The adjustment from lock in to correct speed should be seamless and if you don't over throttle it will be.

 

3) Inverting the tach signal probably needs to be at least tried if you're having issues. Several have reported that by simply inverting the tach signal they've fixed their issues without having to do anything else. Malibu's seem especially to need the tach signal inverted.

 

4) Once you've done all of the above you probably need to adjust your pre-gate, one ball, and 3-ball settings. On my '05 RLXI at 34.2 mph (55K) the pre-gate is 25 (SG manuals says it should be 80), one ball is 18, and three ball is 20 (all lower than default). You'll have to play with it a bit but once dialed in it's sweet. The analogy is that lowering the baseline's etc is like a binding move. Once you get the bindings (or rpm's in this case) in the right place, the fin tweaks (in this case adjusting the pregate/one ball/three ball settings) are to dial it in perfectly. Note that I run a 13 x 13 Acme CNC prop (stock for my boat is 13 x 12, I think...) so my numbers may not work exactly for your boat. My prop runs a bit lower rpm than the stock prop would.

 

BTW I leave my crew weight at I think 350 lbs. Seems to work well there. We usually have two plus gear in the boat while pulling a skier but with 3 in the boat pulling a skier I don't change it and it doesn't seem to matter. FWIW.

 

If anyone needs specifics on how to get to the correct menu's to reset stuff I can post that too. Let me know, happy to help but I figured this was enough for one post.

 

Cheers, Ed @ EZ-Slalom.com

 

STARGAZER OPERATING NOTES

 

Changing Screens/Modes – Use MENU button to scroll to ARROW ICON, press UP. This takes you to MODE screen (Slalom/Jump/Trick). Use MENU to select Mode, press DOWN to select settings within that Mode.

 

Slalom Modes – To select among available modes within Slalom mode highlight ARROW KEY and press UP. When SLALOM is highlighted press DOWN to access different Slalom Modes.

 

Crew Weight – To access, on main Slalom screen highlight SLALOM and press DOWN.

View All Ball Times after a pass – press DOWN key.

False Timer Trigger – Press UP to reset timer.

Tournament Mode – Press UP & Down keys at same time to enter or exit this mode.

Kx Settings – Normal is default, to firm up pull select + or ++, to soften up select -.

SUBMENU SCREEN – To access submenu screen from any Mode press MENU and UP together.

 

PRE-GATE/1-BALL/3-BALL ADJUSTMENTS – In GPS SLALOM mode press ON/OFF and UP at the same time to access.

- PRE-GATE SETTING– Controls speed of boat approaching course. If 1-ball times are slow INCREASE Pre-Gate value; if fast reduce this setting. Default setting is 70. Tweak this value first before tweaking 1-ball and 3-ball settings. Adjust 10 points at a time.

- BALL ONE TIME – Controls 1-ball time and affects 3-ball time as well. If Ball One times are still slow after adjusting Pre-Gate settings increase this value 3-4 points at a time. Default setting is 22.

- BALL THREE TIME – Adjusts 3-ball time. A higher setting speeds up boat, lower setting slows down boat. Adjust 3-4 points at a time. Default setting is 18.

 

Manually Adjust Baselines – Must be in SLALOM CAL mode. Highlight ARROW KEY, press DOWN to access screen, MENU to scroll within screen.

 

Quick Calibrate – In SLALOM CAL mode. Enter set speed and crew weight, drive up to set speed, system engages. Start timing with magnet or hand timer. If you get “OK” time for pass highlight ARROW KEY, press DOWN to access “Quick Calibrate” screen. In this screen press UP to perform calibration. System will confirm “RPM and Speedo Calibrated”. In this screen you can use MENU to scroll around to “Baseline” to manually adjust baseline RPM setting.

 

CAPTURE MODE Calibration – In SLALOM CAL mode highlight SLALOM and press UP. At top of submenu you will see “TIMED” which means you will calibrate using magnetic timing or the hand timer. Press UP to change to CAPTURE. Next select your speed, drive up and engage system. Once engaged use MENU key to highlight CAPTURE. At this point both SLALOM and CAPTURE will be highlighted. Once system reaches correct speed press UP to capture that RPM setting. System will give two quick beeps to confirm it has captured the correct RPM setting. Repeat process for each speed. Works better if your baseline is close to begin with.

 

 

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If you are having problems, definitely check your RPM signal and whether it needs to be inverted. I was having several inconsistent times with stargazer and zbox on a 2004 Mastercraft. I ran the RPm test as outlined in the book I realized that I should invert my signal. once I inverted the signal, everything fell into place
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What @chef23 said regarding overshooting on throttle up. Solves most surging issues assuming tach signal (standard or inverted) is good. Thanks Mark for posting. I've got it saved again (again...).

 

BTW the Operating Notes part of the post above - if you copy/paste that into a Word document it will print out on one sheet of paper. Print it out, have it laminated, and keep it in your boat as a quick referrence. I don't dig around in the menus enough to be good at getting around in them so having the referrence sheet has saved me a few times.

 

Ed

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Some troubleshooting tips in addition to Ed's document.

 

I have no experience with Stargazer in short setups. Heaps of room here. I've done a lot of custom systems with PP (inboards, outboards, IO and jet boats) and have a lot of troubleshooting experience.

 

The factory programmers are very capable. If it was generally the best thing to have a lower baseline, the programming would have been modified by now to do it, and would have come that way in the first place. The suggestion may have merit in short setups but generally baselines should be set as per the factory recommendations.

 

Ed's boat would be drive by wire, most people needing troubleshooting help would be running mechanical systems.

 

You need a good earth. Very few ski boats with mechanical throttle engines are wired properly. I've solved many useless perfect pass installations with a wiring loom. I prefer to err on the side of overkill so I run a pair of 6 sq mm conductor size cables direct to the battery. The positive wire has a 10 amp fuse near the battery. An ignition switched relay near the master module takes the 6mm positive wire in and provides switched power for the master module. Very much the same principal as driving lights on a car - you can google that or ask any auto electrician to do it for you.

 

6 sq mm of conductor size would be overkill and 4mm would be fine too. I use 6mm. Note 4mm CABLE size is much smaller and I would avoid that. I would use at least 4 sq mm conductor size. Don't count the plastic insulation in conductor size as it doesn't conduct.

 

Servo motor operation should be tested. Use the servo test mode. Ensure no slop is present during any tests. When the servo changes direction, the engine throttle should too. No slop, nothing bending, just exactly doing what the servo does. Some linkages bend as the servo changes direction. Very hard for PP to control speed when the engine isn't even being told the right thing to do!

 

Test the servo motor operation with the engine switched off at 1/4, 1/2, 3/4 and full throttle. It should be perfectly smooth. I've seen servo cables jump and catch at different settings. Check and fix it.

 

You may need a return spring. If PP can't get the throttle to return all the way to idle, you need a return spring. Use one as long as you can make fit. Make it only just strong enough to do the job.

 

RPM modes like classic can compensate better for a poor throttle setup as RPM mode gives PP sample data more than 200 times per second. Stargazer takes into account GPS and I think is a little slower than pure RPM mode to make compensations for a poor throttle setup. Z box is much, much more fussy about this. If your system isn't perfect with Stargazer alone, then it could be a bad candidate for Z box.

 

For example, a boat was "fine" with Stargazer but with Z box it was giving nasty hits around some buoys. Horrible to ski behind with Z box. Turned out that the blob of glue that holds the string onto the knob on the servo motor was too big and was catching on the string at certain points in the servo motor rotation. Stargazer was so fast it was able to mostly correct for this (nobody had ever noticed it) but Z box mode couldn't. Fixing this took seconds and improved the pull considerably. This was quickly found with the servo motor tests described above.

 

Another example, I had a chance to visit a customer 3000 miles away and drove his boat. His stargazer was awful. I turned it off and drove by hand and told him it was not nearly right. Hunting, couldn't lock in before the gates, poor times, poor pull, you name it. I built him the wiring loom described above and sent it to him. He told me it transformed the pull of the boat.

 

When I'm troubleshooting a mechanical PP I do this:

 

1. Check the servo motor operation as described

2. Check the voltages and or just go ahead and install the loom

 

Greg

 

 

 

 

 

 

 

 

 

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My boat is DBW and I had no complaints until this year when I tried to use it for trick mode, and then later pulling my wife at 28mph. At 32, 34 and 36 mph a monkey could push the throttle and it will lock in perfect and run great (I do have zbx also). At slower speeds you really need to be careful. Throttle up as follows. Quickly move the RPMs up to about 500rpm north of the baseline, then hold it there. If you allow RPMs to keep rising until it beeps, you're screwed. At higher speeds, it doesn't matter. I have done some things with the advice of the guys at PP and it is somewhat better, but there is no question that it requires the right pull up to work. Problem is, even with a lot of practice sometimes I can't get it right and we surge our way all the way down the course. If @jody_seal comes up with a way to ZO my boat without having to repower it, I'm likely to do it.
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FWIW @GregHind my boat is not DBW it's mechanical. All the SG equiped DBW boats I've ever had contact with had absolutely no issue with SG. In my boat no issue with SG, dials in perfectly 99+% of the time, including 28 and 30 mph. The wiring loom you described above sounds like a really good idea too, my first spring project. Next spring.
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Ed, I think the wiring harness may help you. I'd be interested to see if it makes any difference. Malibu boats are normally better with factory PP wiring than most smaller manufacturers but I think it still may help.

 

I've looked into the 300rpm base issue you mentioned and it shouldn't be necessary. The factory programmer has not heard of this workaround being necessary.

 

I'm guessing you have the earlier Z box software. Version 8.0.0?? Would you please let me know?

 

Version 8.0.2 is apparently a major help with short setups. Might be worth you upgrading prior to next season.

 

I'm not surprised to see Z box need a couple of software updates to get right. Zero Off took quite while to get their system to a point that skiers liked it.

 

Greg

 

 

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Hi Greg. I do not have Z-Box at all and don't feel any pressing need to get it. I'm perfectly happy with SG and don't ski tournaments much so the whole ZO thing is a non issue to me. The no-magnets feature would be nice though. Is that available stand alone or does it require Z-Box?

 

All I can tell you about dropping the baseline is that it works for almost everyone who I'm aware has tried it. I'm not surprised that the programmers aren't too excited about someone second guessing them, the engineers in the office usually don't like the guys on the job site telling them they're off point a bit (no offense to you engineers out here intended). A lot of the "fixes" for Z-Box I've read about came from users trial-and-error, as they did for Classic PP and SG, not from the programmers. Shouldn't work in theory but in the field it's a different story. I only throw it out for the sake of giving folks having issues with SG something based in the experience of several who read and post here something to try when all else has failed. I've received plenty of feedback from a lot of folks that it worked for them as it did for me. I've nothing to gain here, just trying to be helpful. Try it or don't folks, it may or may not help.

 

SG will occasionally freak on me once every blue moon or so but as time has gone on its happened less and less, I tend to think that when it happens it's due to momentarily losing GPS signal but that's just a guess. I find it surprising that folks are still reporting surging issues with SG as I very rarely see it myself. That's the only reason I wrote the above workarounds. For most who have tried some/all of them, they work.

 

Ed

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Hi Ed, I have a lot of respect for what you say, I've dealt with you in the past and you are a capable and particular person. And a longtime skier.

 

You have the old software and it would be worth updating to the latest GPS no magnet software. I think it would help a lot with your short setups. Hopefully you may no longer need the workaround but either way it should settle in much quicker.

 

I suspect you can get this software for less without the GPS no magnet upgrade but I'd do both. No magnet is nice!

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Any information on updates since the initial release of version 8?

 

I received mine in February, & did receive an update a week later, though it didn't change the version number form 8.0.00, it simply allowed crew weight to be displayed in kg's.

 

Whould be interested to hear what changes were made during the season, & what improvements were worked on.

 

Gotta totally agree with Greg on the No Magnets feature. Finally disconnected out smart timer last week. Gone are the false triggerings we often got crossing the wake on our turn.

 

That was one of the biggest driver input issues we had with getting up to speed on our short setup & avoiding false starting of the timer.

 

Were no able to get the revs up sooner with no need to try & drive to avoid false timer starts.

 

Cheers

 

Phil

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Hi Phil

Since you already have 8.0.0 the upgrade cost for you should be quite low. The upgrade is available from PP directly. As you are skiing now, if you did the upgrade you could give some feedback to this forum over the American winter.

 

This upgrade should help short setups. I'm sure it does lots of over little things too. 8.0.0 is basically version 1 of the z box software. I'll be upgrading too.

 

Greg

 

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Great thread @horton this should be in the classic thread section. Can't wait to apply some of these tips- I'm moving from a short setup to an even shorter setup so it looks like a decrease in base RPM is in order! Every time somebody new drives my boat I have to remind them not to pin the throttle
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