Perfect Pass Star Gazer with Z Box vs Zero Off - Apples to Oranges comparison?

[Scott Russell]

Please bear with me, as I'm trying to re-acquaint myself with new skiing technology after having been out of skiing for 28 years. 

So I've been reading all I can about PP and ZO. The one thing I see consistently is that most seem to be of the opinion that ZO is superior after having been pulled by a boat that has it, vs their own boat with PP Star Gazer and a Z-Box (with a few exceptions). 
 

You always hear people refer to the horsepower their boats have, but you very rarely ever hear them mention the torque their engines produce, OR the rpm at which they produce said horsepower an torque numbers. When old my Stars and Stripes was in the course, it turned around 3600rpm at 36 mph. From what I can find, it appears that engine made around 240hp @ 4200 rpm, and around 340 ft lbs of torque in the mid 3k range (information seems to vary from source to source on the torque of these engines). So the boat is pulling the skier through the course at, or at least close to peak torque, which perfect, because torque is the number that matters to a skier.

The newer boats equipped with Zero Off from the factory typically have a published horsepower anywhere from the high 300's, to as much as 430 for the latest and greatest Ilmor 6.2L and I think there might ever be a supercharged version with over 600 hp?. That in itself is pretty far from the Boss HO 351 @ 310 horsepower @ 4200 rpm, and the Boss has around 360 ft lbs of torque (in my searches I've seen that number published as high as 385 ft lbs.). . 

The eye opener is that the Ilmor 6.2L makes 479 Ft lbs of torque @ 4000 rpm. I've never ridden in a boat with one of these engines, so I have no idea what the rpm is @ 36 mph, but I'd bet it's between 3600 and 4000rpm. And BTW, the 6.2L makes it's 430 hp at a whopping 5400 rpm, which I'd would think isn't of much value to a skier, since the boat will never see that rpm in the course. Again, it's torque that matters to a skier and the rpm that torque occurs in the power curve. The 6.2 is the most outstanding ski boat engine (specification wise) I've ever seen, but I've yet to see anyone mention the 479 ft lbs of torque, they only mention the 430 hp. 

So my question is, is the PP to ZO comparison apples to oranges? At the rpm the engine is running while in the course, the older 350's and 351's are down every bit of 100 ft lbs to the engines in the boats that come equipped with ZO from the factory. 

My thought is that if you put the same power (torque & throttle response, specifically) in an older boat, as the new ones have, how much difference would there REALLY be? I keep reading that ZO is superior, but I can't help but believe that people are missing the fact that you can't have that super quick/strong response when one boat has over 100 ft lbs less torque than the other. 

[03RLXi]

Interesting. You're thinking the available engine torque could be much more significant to skier feel than control via PP vs ZO. To get a proper skier feel comparision it'd have to be based on back to back ski sets at same course using identical hulls with identical DBW engines, similiar engine hours, identical prop. One with PP & Zbox, other with ZO. Probably only possible using two boats from late 2000s since newer boats tend to have ZO integrated in from day one. 

[UWSkier]

Adding to the complexity further is the fact that 6.2L is a Gen5 Direct Injected engine which responds to changes in throttle inputs faster than a TBI or PFI engine.  You are correct in your guesstimation that these new engines are next to impossible to approximate with an older setup.  The mechanical nature of PP with ZBox will never be able to respond quite as quickly or as forcefully as a Gen5 ZO setup.  But you can get close-enough for all but the most hardcore skiers.  Set the KX to ++ and prop your boat down to get a torque multiplier, and you might get close.

But at some point, the only way to get the "new boat" pull is to buy a "new boat."

[MISkier]

Don't forget that the older boats are likely 500-800 pounds lighter than the new boats.  Some of that extra weight in the new boats is offsetting the torque advantage.  But the throttle response may be the bigger factor.

I have the perspective of an old boat style and weight (Malibu LX) with an old engine (320 HP 5.7L) and factory Zero Off.  It was delivered that way in 2009.  It's noticeably different from both the PerfectPass zBox on older boats with older mechanical throttles and the Zero Off on the bigger boats with the 6.2 engines.

The 6.2 engine is absolutely the way to go in tow boats.  Very nice pull.

[Scott Russell]

3 minutes ago, 03RLXi said:

Interesting. You're thinking the available engine torque could be much more significant to skier feel than control via PP vs ZO. To get a proper skier feel comparison it'd have to be based on back to back ski sets at same course using identical hulls with identical DBW engines, similar engine hours, identical prop. One with PP & Zbox, other with ZO. Probably only possible using two boats from late 2000s since newer boats tend to have ZO integrated in from day one. 

What I'd love to do is build an older boat with the modern torque level and put BOTH systems on the SAME boat and have a few skiers run back to back sets, one with PP and one with ZO. That way the boat is not a variable AT ALL. 

I'd like to do this with a 97-01 Nautique. Great hull with great wake, just needs a modern heart transplant and updated electronics. Even with two identical boats, I think you'd still have variables between the two. Doing the testing with one boat eliminates any possibility of variances between boats. 

[jpwhit]

If you're talking PP with mechanical servo vs Zero Off with DBW, then there is no comparison in how quickly the system can make changes to the power output of the engine. I'm personally a little confused now about what PP does and doesn't support relative to DBW, but I really don't care enough to call them and ask. 

ZO uses high update rate GPS speed data, accelerometer data, mapping of the course so it knows when it's approaching gates and skier balls. Therefore, the control algorithms it uses are quite sophisticated. And they are also considered proprietary by eControls. Zbox adds accelerometer data to perfect pass in an attempt to try and duplicate the behavior of Zero Off. But it's at best an approximation. 

Unless you budget is super tight, I just don't see any good reason to do anything other than Zero Off. 

Zero Off doesn't require any tuning or messing with parameters. That in itself is huge IMO. 

@Scott Russell have you ever skied behind a ZO boat so you can see for yourself how different it is from hand driving or legacy Perfect Pass. If not, I really think that should be your next step. First-hand experience with skiing behind a ZO boat is likely to be a little eye opening. Just post up here locations where you can meet someone to ski. I think there is likely plenty of time left in the season to get a test ride in. I typically ski into November for example. 

[Scott Russell]

7 minutes ago, MISkier said:

Don't forget that the older boats are likely 500-800 pounds lighter than the new boats.  Some of that extra weight in the new boats is offsetting the torque advantage.  But the throttle response may be the bigger factor.

I have the perspective of an old boat style and weight (Malibu LX) with an old engine (320 HP 5.7L) and factory Zero Off.  It was delivered that way in 2009.  It's noticeably different from both the PerfectPass zBox on older boats with older mechanical throttles and the Zero Off on the bigger boats with the 6.2 engines.

The 6.2 engine is absolutely the way to go in tow boats.  Very nice pull.

Your experience with the 09 Malibu would seem to confirm my suspicion. And yes, from everything I find on it, the 6.2 seems to be the gold standard.  

[Scott Russell]

2 hours ago, jpwhit said:

If you're talking PP with mechanical servo vs Zero Off with DBW, then there is no comparison in how quickly the system can make changes to the power output of the engine. I'm personally a little confused now about what PP does and doesn't support relative to DBW, but I really don't care enough to call them and ask. 

ZO uses high update rate GPS speed data, accelerometer data, mapping of the course so it knows when it's approaching gates and skier balls. Therefore, the control algorithms it uses are quite sophisticated. And they are also considered proprietary by eControls. Zbox adds accelerometer data to perfect pass in an attempt to try and duplicate the behavior of Zero Off. But it's at best an approximation. 

Unless you budget is super tight, I just don't see any good reason to do anything other than Zero Off. 

Zero Off doesn't require any tuning or messing with parameters. That in itself is huge IMO. 

@Scott Russell have you ever skied behind a ZO boat so you can see for yourself how different it is from hand driving or legacy Perfect Pass. If not, I really think that should be your next step. First-hand experience with skiing behind a ZO boat is likely to be a little eye opening. Just post up here locations where you can meet someone to ski. I think there is likely plenty of time left in the season to get a test ride in. I typically ski into November for example. 

I'd love to do that, but I've got a right knee that is bone on bone right now it's being replaced Nov 13th. I'll be good go in the spring though. 
 

The mystery of ZO to me is why it requires an eControls ECU for the engine. From everything I can find about it, all of what makes it great is in the head unit itself. All DBW systems, including aftermarket stand alone systems, take a 5v signal from a potentiometer in the pedal position sensor (or throttle lever in a boat) and that 5v signal goes to the ECU and it is converted (or translated if you will) to a 12v waveform and the ECU sends the translated 12v signal to the motor on the throttle body. Then the two throttle position sensors on the end of the throttle shaft send their (matching) 5v signals back to the ECU. If they ever stop matching it sets a diagnostic trouble code and the engine goes into limp model until the output of the two tps sensors match again. 

The ECU can bypass the pedal position sensor. For example, in a car/truck when traction control is activated, vehicle speed and wheel speed stop matching, which triggers activation of the traction control, and the pedal position sensor input is disregarded and the traction control algorithm takes over control of the throttle body. There are a LOT of potential things that could be done in this fashion, disabling the pedal, or partially disabling it.

In boat with ZO, from the sound of it, once you set your speed and activate it, you push the throttle wide open and it maintains whatever speed you set, but for safety reasons, if you pull the throttle back further than a setting required to maintain the set speed, the throttle will allow you to slow the boat. Whether it take back over if you throttle up without turning ZO off, I have no idea. My guess would be that throttling below the set speed turns it off. The same signal that ZO sends to an eControls ECU to allow it take command of the throttle (or partial control) could also work with an aftermarket ECU. I'm just wondering if there is information the ECU is providing the ZO head unit that it needs to function that an aftermarket ECU wouldn't have. GPS is a possibility, but it would make far more sense to have the GPS in the head unit rather than the ECU. A tach signal for engine rpm is likely, but that's just a simple one wire connection to ANY ignition system. If there is some proprietary encryption voodoo to keep out other manufacturers ECU's then that would be hard to crack. 

I'm just wondering why limit your sales potential. By all accounts is a fine piece of electrical engineering, why be like Apple? It's annoying. I have a friend who designs and builds devices like ZO for drag racing. I'd love to take one to him and see if he can find out what the "protection" is that keeps it from working with other ECU's. If they'd simply publish why they don't want it used, or why it can't be used with other ECU's I wouldn't be so curious, but apparently that's not the case. 

[rockdog]

@Scott Russell agree with your comments re horsepower v torque. For example the DI 5.3 puts out the same torque as a 6.0 but with less horsepower. Not sure where in the RPM range the numbers appear but it's interesting for sure. I've neither driven or skied behind a 5.3 so can't compare the feel but most on here would say the 6.0 is better. The DI 6.2 is a noticeable step up.

[ETskier]

I don't remember when exactly the 5.3 became an option, but I do remember nobody liked the feel, myself included. Maybe it was because at the time most folks had 5.7s or 6.0s.  One of my ski partners has a  2019 Ski Nautique with the 5.3. To us it seems much closer to the 6.2 than others. Maybe they reworked the algorithms or something. The 6.2 is still king right now. 

[MISkier]

2 hours ago, Scott Russell said:

The mystery of ZO to me is why it requires an eControls ECU for the engine. From everything I can find about it, all of what makes it great is in the head unit itself.

I seem to recall that the actual ZO algorithms were embedded in the eControls ECU itself and the head unit is just an interface/menu system.  The ECU is particularly important as it utilizes a CANbus mechanism to not only manage throttle response, but to do so while being aware of torque and horsepower curves of the various engines in conjunction with accelerometer measurements and the GPS timing.  I think some of this was in the eControls patent documentation itself.

Regarding the 5.3 engine, I never liked it.  Whatever they were doing for the ZO calibration of algorithms for that engine seemed harsh, unforgiving, and abrupt to me.  I really don't care much for some of the 6.0 engines setup either.  

[jjackkrash]

If you spike a new boat with a 6.2L DI engine and zero off it will grab ahold of you and break you in half in a way that an older carby with Z-box won't.  Don't spike/overyoke the boat and there's not nearly as much of a difference.  So if you are used to training behind an older boat and like to yoke you won't like the result if you roll into a tournament unprepared.  It's the penalty for inefficiency that I see as the big difference.    

[MDB1056]

@Scott Russell- again/ unless you are training to ski competitively at a HIGH level, ZO is NOT needed, adds nothing, isn’t worth it , etc. Are we there yet??????

[Drago]

@Scott RussellThe very first PP was speed based, it was terrible. Then came rpm based, the driver had to add rpm for crew weight, the anticipated pull of the skier, and wind (and current if in a river). It was a big guessing game and some skiers loved it because they could "pull it down" and get a slow but in tolerance time. There were magnets under buoys for the timing. If you didn't pull, it would go really fast. It came in hot at the gate.

Then came PP Stargazer: was "GPS based" it came in hot at the gate too, then changed speed at the 3 ball (heinous and ridiculous )

apparently with lots of inputs, one can get stargazer to work pretty well, and I guess Z-box is close to Zero Off.

The limiting factor is response time via a throttle cable.

ZO is always tbw with accelerometers. No inputs from the driver except for the skier's choice of pull type and speed. If you select 34 mph and just stand there, it goes 34 mph. If you pull really hard, it pulls back. It tries to get a perfect time. 
 

New boats are much  wider and heavier. New engines are really strong, they don't need to be at their peak torque curve, I don't think, the manufacturers prop them accordingly. ZO needs to know your engine size and prop. I think our 6.2 L 2020 prostar goes maybe 40 mph at 6,400' above sea level. Not sure what the rpm's are at 36 mph, but higher than older engines. 
 

I have a '97 Nautique with pp (not Stargazer) that I still love to freeski behind. No way would I run it in the course. I’m not sure anyone that skis tournaments would choose to train behind a pp boat if they have a choice.

[Horton]

@MDB1056 that brings me back to my question from a day or two ago. Is this a hobby project or is this a cool sleeper tournament boat? Just about any old tournament boat with a new 6.0 + ZO would likely be a decent training boat and pretty cool.  At Bell Acqua there is an old ProStar with a new engine plus ZO that I really want to keep behind. Repowers are pretty standard procedure these days.

Some fire breathing crazy spec custom engine + pp in an old tournament boat is a cool hobby but it's not a tournament training boat. I'm not against it but I'm just trying to differentiate the goals.

 

[Drago]

Oh, also @Scott Russell, the 5.7 liter gt40  in the '97 Nautique will pull a 36 mph skier at 6,400'. The 5.7 L engine in a 2014+ prostar or Nautique 200 won't. 

[Scott Russell]

13 minutes ago, Drago said:

Oh, also @Scott Russell, the 5.7 liter gt40  in the '97 Nautique will pull a 36 mph skier at 6,400'. The 5.7 L engine in a 2014+ prostar or Nautique 200 won't. 

Wow, that's wild. I wouldn't have thought that. I'm proud to hear that. My truck is a Ford and I have 4 Mustangs, so it's fair say I like Fords 😄 

[Scott Russell]

45 minutes ago, Horton said:

@MDB1056 that brings me back to my question from a day or two ago. Is this a hobby project or is this a cool sleeper tournament boat? Just about any old tournament boat with a new 6.0 + ZO would likely be a decent training boat and pretty cool.  At Bell Acqua there is an old ProStar with a new engine plus ZO that I really want to keep behind. Repowers are pretty standard procedure these days.

Some fire breathing crazy spec custom engine + pp in an old tournament boat is a cool hobby but it's not a tournament training boat. I'm not against it but I'm just trying to differentiate the goals.

 

The fun for me is building something I enjoy, but you make very valid point. The fact is, I could buy a new 6.2 and ZO and put it in an older boat for a quarter of what I'd pay for 3-4 year old boat and to your point, it would be a good training boat. 

That may be how it ends up happening. But the main reason I toy with the idea of building a 351 based engine is because I already have a lot of the most expensive parts I need. That and it just sounds like a fun project that would be a blast to both drive, and ski behind. The frustrating part is knowing it would never be good training boat for anyone unless it has ZO. 

Maybe a win win would be to put my engine in for a season or two till I'm skiing well enough to be worthy of an actual training level boat and then swap in a new 6.2. I could sell the 427 for more than the Ilmor 6.2 costs. 

 

[Horton]

@Scott Russell

Additionally, I cannot emphasize enough that a 6.2 is unnecessary ( cost and power). Given a choice I would always choose a 6.0. The 6.2 is only popular because Nautique forced it on us and they have a super high drag hull. At sea level the 6L ProStar is standard and the pro jumper guys say it's good enough up to 230 ft. so unless you're going to jump more than 230....

I have skied the 6.2 l in the ProStar once and I admit it felt good but not enough. better to justify the additional cost.

I understand why if you're building a hot rod there's no such thing as too much power but in a slalom boat there's a point where you're just throwing money away and not creating a better boat.

[Scott Russell]

1 hour ago, Drago said:

@Scott RussellThe very first PP was speed based, it was terrible. Then came rpm based, the driver had to add rpm for crew weight, the anticipated pull of the skier, and wind (and current if in a river). It was a big guessing game and some skiers loved it because they could "pull it down" and get a slow but in tolerance time. There were magnets under buoys for the timing. If you didn't pull, it would go really fast. It came in hot at the gate.

Then came PP Stargazer: was "GPS based" it came in hot at the gate too, then changed speed at the 3 ball (heinous and ridiculous )

apparently with lots of inputs, one can get stargazer to work pretty well, and I guess Z-box is close to Zero Off.

The limiting factor is response time via a throttle cable.

ZO is always tbw with accelerometers. No inputs from the driver except for the skier's choice of pull type and speed. If you select 34 mph and just stand there, it goes 34 mph. If you pull really hard, it pulls back. It tries to get a perfect time. 
 

New boats are much  wider and heavier. New engines are really strong, they don't need to be at their peak torque curve, I don't think, the manufacturers prop them accordingly. ZO needs to know your engine size and prop. I think our 6.2 L 2020 prostar goes maybe 40 mph at 6,400' above sea level. Not sure what the rpm's are at 36 mph, but higher than older engines. 
 

I have a '97 Nautique with pp (not Stargazer) that I still love to freeski behind. No way would I run it in the course. I’m not sure anyone that skis tournaments would choose to train behind a pp boat if they have a choice.

We have incorporated single axis, the two axis, and now three axis g-meters in drag car tuning strategies. First it was just for recognizing a loss of acceleration and pulling ignition timing to kill power. Then NLR patented using it for g-based boost control. Then the side to side axis was used to automatically deploy your chutes if the car got sideways beyond the number of degrees you set. Now the up and down axis is used to both pull timing and/or cut boost to control a wheelie that no person would have the reflexes to control. 

I'd bet ZO is likely pulling ignition timing when it needs to quickly scrub speed. It's an instant and potentially dramatic cut in power that simply closing the throttle blade cannot match. Then it has the advantage of direction injection in the 6.2, which is putting fuel directly in the combustion chamber, which will always be a fraction quicker than port injection. 

I'm thinking ZO is kinda like very high end audio. You reach a point where you almost need a highly trained ear to hear the difference. Having never experienced ZO personally, I don't know for sure, but it sure sounds like you've really got to be a high level skier to appreciate the nuances that make it superior. 

[Scott Russell]

17 minutes ago, Horton said:

@Scott Russell

Additionally, I cannot emphasize enough that a 6.2 is unnecessary ( cost and power). Given a choice I would always choose a 6.0. The 6.2 is only popular because Nautique forced it on us and they have a super high drag hull. At sea level the 6L ProStar is standard and the pro jumper guys say it's good enough up to 230 ft. so unless you're going to jump more than 230....

I have skied the 6.2 l in the ProStar once and I admit it felt good but not enough. better to justify the additional cost.

I understand why if you're building a hot rod there's no such thing as too much power but in a slalom boat there's a point where you're just throwing money away and not creating a better boat.

I'll never jump. Skied past our club's jump for a decade and was never the least bit interested in learning to jump. I just loved to slalom.

I suppose in the back of my mind I was hoping that if I could put enough torque in a boat, I could run a prop so big that no skier could alter the boat speed significantly enough to alter the boat's timing through the course. In reality that might even be possible, but I'm pretty sure it would take some ridiculous purpose built boat to accommodate the prop it would take to accomplish that feat. Either way, not very realistic. 

Maybe just build to it fling a jumper 300ft 😄 🤣 😂 

[Onside135]

Already been done…

 

https://www.mastercraft.com/news/freddy-krueger-breaks-world-skifly-record-soaring-312-feet-behind-a-mastercraft-prostar-boat-inaugural-world-of-x-games-mastercraft-throwdown

[chrislandy]

@Scott Russell back to my comment on the other thread, you'll see that the 6.2 max HP is 100rpm off the hard limit of 5500, thus being able to provide all available power throughout the rpm range. 5500rpm is the transmission limit, with a torque limit of around 550lbft. The trans on the later boats is not 1:1 and use a different prop to the earlier boats.

You mentioned which rpm to speed, I don't know specifics, but the boat will top out at round 45mph for barefooting (not that you'd want to foot that quickly), it will be roughly linear between 2k @ plane (~18mph) and 5.5k @ 45mph with a slight taper towards the upper limit.

eControls and ZO are the same company umbrella which is why ZO can only be fitted to an eControls ECM.

In your position, I would look at PPwZbox & DBW module for non eControls ECM.

 

 

[Mastercrafter]

5 hours ago, Scott Russell said:

I suppose in the back of my mind I was hoping that if I could put enough torque in a boat, I could run a prop so big that no skier could alter the boat speed significantly enough to alter the boat's timing through the course. In reality that might even be possible, but I'm pretty sure it would take some ridiculous purpose built boat to accommodate the prop it would take to accomplish that feat.

ZO holds times to 1/100 every single time. It’s not just in tolerance.. it’s 16.94, 16.95, or 16.96. I can’t recall ever seeing another time in a tournament but I’m sure there’s probably an outlier. 5.7, 6.0, 6.2… doesn’t take a monster engine and prop to keep the boat from slowing down with ZO. 

[Horton]

I think a point that maybe missing is the following:

it's not that the pull from ZO is perfect. it's more that it is a very specific, very prescriptive response to the pull of the skier. It's not about more torque or horsepower. It's about a very specific response and the immediacy of that response. If I were king for the day and had to redesign it, ZO would potentially be very different.

The result of the current state is that a skier from Botswana can show up to a tournament in Uzbekistan and if there is a zero off boat, the pull they're going to get is similar to what they get at home.

from an outsider the difference between the pull of a ProStar and a Nautique probably looks negligible but it's absolutely massive to those of us who have to deal with it. The perceived differences are arguably the speed of throttle response.

I suppose a homespun boat and engine combination with zero off could result in a great feeling boat, but more likely the end result would just be a bizarre, odd duck.

[ReallyGottaSki]

Im thinking the 427 is just too much, it gives up the benefits of small boat economy and  longevity due to side loading from long stroke and short rod .  

heads, smart cam, intake, took a 40 yo 351 that i could swing the speed +/- 2mph with no throttle inputs, and became to +/- 0.5 mph. just engine.  while exceeding 50 mph as a party trick.

Throttle response becomes both immediate and linear in all areas. Compensation, when applied, is instant, one from the improved VE and two from being in the meat of a flat torque peak and well within the useable range of the primaries,  verses skiing where they go flat. 

yet still be docile and predictable enough my daughter can enjoy pulling me slalom and not fret about speed because the speed delta was now inconsequential  (no pp) . When this boat gets pp, its not going to be doing much throttle jinking

Maybe a 393 gets you both modern big-boat power levels but can still let it spin 

[Scott Russell]

7 hours ago, chrislandy said:

@Scott Russell back to my comment on the other thread, you'll see that the 6.2 max HP is 100rpm off the hard limit of 5500, thus being able to provide all available power throughout the rpm range. 5500rpm is the transmission limit, with a torque limit of around 550lbft. The trans on the later boats is not 1:1 and use a different prop to the earlier boats.

You mentioned which rpm to speed, I don't know specifics, but the boat will top out at round 45mph for barefooting (not that you'd want to foot that quickly), it will be roughly linear between 2k @ plane (~18mph) and 5.5k @ 45mph with a slight taper towards the upper limit.

eControls and ZO are the same company umbrella which is why ZO can only be fitted to an eControls ECM.

In your position, I would look at PPwZbox & DBW module for non eControls ECM.

 

 

That's good information about the trans limitations. I didn't realize that. Thanks. 

If i end up doing the project I'd like to do I'm pretty sure I'll start with a 97-01 Nautique, which has a 1.23:1 transmission. 

The engine I plan to build will be drive by wire. But it will produce brutal torque at around 3500-4200 rpm, so with the under drive trans, it's going need a large prop with quite a bit of pitch. 

It's hard to know the future, but from where I am now, I may never try to ski any sort of sanctioned event. That said, getting used to star gazer with a Z-box for DBW instead of Zero Off is not really an issue for me personally. It would just be nice if I could make ZO work on my boat so people who DO ski sanctioned events won't be reluctant to ski behind it. From everything I've learned so far, that will never happen. 

[Drago]

Not sure pp can play with dbw ...

[Scott Russell]

1 hour ago, Horton said:

from an outsider the difference between the pull of a ProStar and a Nautique probably looks negligible but it's absolutely massive to those of us who have to deal with it. The perceived differences are arguably the speed of throttle response.

I've always skied behind either a Master Craft or a Supreme (remember, this was nearly 30 years ago). Honestly, my all time favorite Competition boat purely from an appearance standpoint was the 80's Nautique 2001, but two people in our club had them, and I didn't like them compared to mine and other Pro Stars. The Supreme was somewhere in between, and wouldn't have been my choice, but it was my closest friend in the club's boat, so we skied together a lot. 

Also, I wanted to ask, when you talk about the perceived differences between MC and SN being the speed of the throttle response, are both boats equipped with Gasoline Direct Injection engines? If they are, and they both have ZO, I'm curious what is causing the discrepancy? Any thoughts on that? I'm just curious and trying to soak in all I can while I have people who really know from experience and are willing to share. 

[MISkier]

There are different ZO software levels for each boat, according to how the manufacturer wants to tune their boat behavior with the particular engine and transmission, etc. setup they have.  I recall skiing behind a MasterCraft years ago that was accidentally loaded with the incorrect ZO software for a Nautique.  Awful pull.  But, that software versioning is why each manufacturer can feel slightly different, even with identical engines.  It's just like some of the tuner cars you see that are basically achieved by adjusting the ECM with a laptop.  They are different than factory settings.

Everything is controlled by that unit, including how responsive they want the throttle adjustments to be, regardless of inherent DBW capability.

[Sethro]

8 minutes ago, Drago said:

Not sure pp can play with dbw ...

2006 and up Malibu is DBW and PerfectPass supports that. I can’t speak for other brands. 

[Scott Russell]

1 hour ago, Horton said:

I think a point that maybe missing is the following:

it's not that the pull from ZO is perfect. it's more that it is a very specific, very prescriptive response to the pull of the skier. It's not about more torque or horsepower. It's about a very specific response and the immediacy of that response. If I were king for the day and had to redesign it, ZO would potentially be very different.

I have no frame of reference, haven't never ridden, driven or skied a boat with ZO but I'm curious what you would do differently than ZO does today? I talked to a friend who designs and builds the GPS and G-meter and wheel speed management products I use on my race cars about looking into how his current devices might be applied via a Holley Dominator ECU for a speed control application in a boat (I explained the course to him). His products sample at a thousand times per second and are getting faster all the time. In drag racing when you are trying to apply 2000hp to the racing surface on a tire that is only 28" tall and 10.5" wide, your systems have to be able to monitor and react at speeds unimaginable to most sports. That is the world I have been in for the last 25 years, and I've become an accomplished tuner using these tools. It would be interesting to hear your thoughts on what you do differently if you could start over, since I know you have a lot of experience behind a lot of different boats with ZO so I could try and apply them via some these devices I'm already very familiar with. 

[MISkier]

I believe the ZO versus PP patent case says that PP cannot be installed on new boats after whatever date the case was settled.  I think that was somewhere in 2008.

[jpwhit]

I have a 2019 ProStar at my lake house and a 2012 Nautique 200 at the ski club near my main house. And even as a 35 off skier, I also am bothered by the differences in the pull between these 2 boats. It's not at all unworkable for me, but it is somewhat annoying enough to cause me to try to minimize it. I do use different ZO settings between the 2, but still notice the difference. @Mastercrafter and I have messaged about this some as well, because he also has a similar situations. We're both in the process of trying the 3 blade "jump prop" on the ProStars to see if that equalizes things somewhat. Eric at OJ props suggested trying that. 

So clearly ZO isn't a magic bullet for making all boats ski exactly the same. And like @Horton, if I had my way I certainly also believe that ZO algorithms could be modified to make the situation even better. And when the patents expire, which is only a few years off, a competing system could be developed that had more emphasis on consistency across boats and engines as well as other improvements. I think this goes to show just how much very tiny differences in the control systems can be felt by a skier. And the difference boat to boat with ZO is tiny compared to the difference I've felt skiing behind a PP Stargazer / zbox setup. I think it's also the case that some people are much more perceptive and / or bothered by these small differences. If you're not, and you're happy with zbox, that's great I think you're fortunate. But I don't think that means everybody will be happy with that setup. 

In terms of why the differences, I don't think it's fundamentally because of the different ZO tunes between boat manufacturers and engines. I think it's mostly caused by differences in transmissions ratios, propeller designs, and small engine tuning differences. But I also think it's the case that ZO's design goal was to make the system very easy to use for the end user and to almost completely eliminate out of tolerance passes. I doubt they had any intention to try and make the system feel as close as possible boat to boat and engine to engine. And with their near monopoly on the speed control market at the moment, there is absolutely no business incentive to spend money changing anything right now. 

I also may sound like I'm a big supporter of ZO and anti-perfect pass. But that's not really the case. I think the transition from perfect pass to ZO for tournament skiing was handled extremely poorly and did cause real harm to the sport. But I blame that less on eControls and more on how the governing bodies of water skiing handled the transition. eControls did in my view "invent" a better speed control system than what existed in the market before it. Especially in terms of end user usability and more consistently in reducing the occurrences of re-rides from out of tolerance passes. And I can't really blame them for using patent law to protect their innovation. Let's not forget that Perfect Pass was also protected by patents such that another manufacturer couldn't easily step in and replace them either. And if I'm not mistaken, PP sued ZO over infringing on their patents. In most cases similar to this in the industry, two companies like this with both valid but related patents, most often agree to cross license the intellectual property. And it's typically a win-win for both the manufacturers and the consumers. The governing bodies for waterskiing could have, and should have, taken a stand that they would only accept such an arrangement for the tournament approved speed control they would support. If they had taken this route, the transition wouldn't have been so detrimental to the sport, and we as skier would likely have an even better speed control system today. 

Years ago, I was a much bigger fan of looking for alternatives to ZO. But now I think we're past that in the market because ZO boats can be had for cheap enough IMO. Part of the reason I have that view, is because with the most recent downturn in the boat market. I think it's getting pretty hard to buy an older boat, convert it to ZO, and actually spend less money than buying 2008 - 2011ish ZO boat. Especially if you're really honest about making it an apples to apples comparison. By that i mean really having equivalent boats in terms of the condition of the interior and all aspects of the boat. Also, it's a different story if you also already own a Pre-ZO boat than if you have no boat and are getting into the market. 

I fully expect someone to bring up ... "wait didn't you post earlier that you're converting an 1999 bubble butt Nautique" to a modern engine and Zero Off. Yes I am, but to @Horton's earlier point, I know exactly why I'm doing it. It's not because I'm trying to create the ultimate slalom boat for anybody. Actually, I fully recognize the opposite. Given the current state of Zero Off, it'll probably ski differently than any other boat out there. 

I'm doing it because I just think it’s fun and interesting. I doubt I’ll even keep it in this configuration long term. I’ll probably rip the 6L Ilmor back out of it later for another fun project I have in mind. 

 

[Scott Russell]

40 minutes ago, MISkier said:

I believe the ZO versus PP patent case says that PP cannot be installed on new boats after whatever date the case was settled.  I think that was somewhere in 2008.

Wow! eControls and ZO have a stranglehold on the new boat market. Crazy! I wonder when their patent runs out. Normally they only last 10 years unless you get a new application approved, then they will extend. 

[Scott Russell]

1 hour ago, Drago said:

Not sure pp can play with dbw ...

https://perfectpass.com/product/stargazer-three-event-upgrade

Looks like they offer the above upgrade for DBW

[MISkier]

@Scott Russell, I'm not sure of their patent duration.  But, the agreement/settlement between eControls and PerfectPass in 2008 did give eControls the monopoly on new boat speed control going forward.  I believe the 2009 model year was the first year that it was exercised.

[Scott Russell]

54 minutes ago, MISkier said:

There are different ZO software levels for each boat, according to how the manufacturer wants to tune their boat behavior with the particular engine and transmission, etc. setup they have.  I recall skiing behind a MasterCraft years ago that was accidentally loaded with the incorrect ZO software for a Nautique.  Awful pull.  But, that software versioning is why each manufacturer can feel slightly different, even with identical engines.  It's just like some of the tuner cars you see that are basically achieved by adjusting the ECM with a laptop.  They are different than factory settings.

Everything is controlled by that unit, including how responsive they want the throttle adjustments to be, regardless of inherent DBW capability.

Thanks for that. That would seem to answer my question to John earlier. He said that his MC vs a SN, the pull wasn't the same. I asked if both had a direct injection engine, and if they did, was asking what he thought the discrepancy was caused by. So the manufacturers can tweak to suit their individual wants. That explains a lot. I'm actually encouraged knowing it's not just a one size fits all generic system. I am a drag racer and I tune power adder (supercharged or turbo, but not nitrous) cars and have been tuning stand alone EFI systems on these cars since the late 90's. If ZO can be tweaked by the manufacturer, it's not as totally locked down as I was thinking. 

[Scott Russell]

3 minutes ago, MISkier said:

@Scott Russell, I'm not sure of their patent duration.  But, the agreement/settlement between eControls and PerfectPass in 2008 did give eControls the monopoly on new boat speed control going forward.  I believe the 2009 model year was the first year that it was exercised.

That's just nuts to me. So the United States Patent office gave eControls and their ZO product a monopoly ....   They must have some very skilled lobbyists in DC. 

[MISkier]

@Scott Russell, I don't think the manufacturers are actually doing the tuning.  I believe that eControls is involved to produce the software image for them to load.  I think it is a collaborative process rather than an open interface that allows customization by either manufacturers or end users.  I think the software image is produced and managed by eControls to be provided to the manufacturers.  Hopefully, someone else with direct involvement in this process can comment.  I think there are skiers and drivers on this forum who are consulted for this tuning and calibration effort.

[MISkier]

@Scott Russell, the patent office did not create the monopoly.  Both parties agreed to it as part of their lawsuit.  They settled with each other before it even got to court, if I recall correctly.  Part of that agreement was that eControls would not be able to market directly to boat owners with existing mechanical throttle or pre-2009 DBW setup.  So, PerfectPass received that market as theirs.  The re-power option you see with old boats was apparently not included in the agreement and is the workaround for those wanting true ZO in old boats.

Now, if a third party were to produce a new speed control system for either of these markets (new or old), then the viability and validity of the patents would come into play and the other company would have to defend such a challenge.  I see a new challenger as unlikely, as there are relationships within the boat manufacturer, speed control company, and water ski governing body that make the entry into the market difficult.

[Horton]

@Scott Russell If you last skied behind was a 1993 boat think of it this way.... How similar in performance is a 1993 Corvette to a 2023 Corvette? Pretty much unrelated except for the name plate?

The point that I keep trying to make is skiers have adapted to a very specific throttle response. Even behind the brands of boat we have today the difference between the boats is likely trivial from the outside but critical to skiers who ski tournaments. Any boat that tries to backward engineer the standard will likely be outside the norm.

As I recall there are 12 parameters in the back end of ZO that the ski companies can tweak for the different combinations of engines, hulls and props.   The skiing public does not have access to this dashboard and can not access these settings. 

The skiing public has access to a higher level / standard set of options. As an example when you go from an approved 4 blade prop to a an approved 3 blade prop you need to change that option. 

----------------------------

So this website is my job and how I pay my bills. I run it how I think it will be most successful. If your project looks like it will lead to a very cool restored old boat that performs within the norms of a modern ZO tournament boat, I want to promote what you are doing and follow every nut and bolt. I have endless passion around this idea.

If this project leads to a fun old ski boat hobby project that is cool but impractical as a modern training boat I will likely move these discussions to a different category so only signed in members can read it and more importantly Google will not index the content. I do not want to discourage your project but I do not want it to impact the larger focus of the forum.  The foundation of BallOfSpray is tournament skiing. 

[Horton]

41 minutes ago, jpwhit said:

And when the patents expire, which is only a few years off, a competing system could be developed that had more emphasis on consistency across boats and engines as well as other improvements.

FYI - the brands could make all the boats feel the same. They choose not to. Before the new Nautique the differences were much smaller. I would bet my ski collection that if we had all 4 boats ( including the 200), a smart guy like Will Bush or Freddy Krueger to tweak the back end settings and a wide range of props we could make the boats feel a lot closer. 

[Scott Russell]

33 minutes ago, jpwhit said:

I have a 2019 ProStar at my lake house and a 2012 Nautique 200 at the ski club near my main house. And even as a 35 off skier, I also am bothered by the differences in the pull between these 2 boats. It's not at all unworkable for me, but it is somewhat annoying enough to cause me to try to minimize it. I do use different ZO settings between the 2, but still notice the difference. @Mastercrafter and I have messaged about this some as well, because he also has a similar situations. We're both in the process of trying the 3 blade "jump prop" on the ProStars to see if that equalizes things somewhat. Eric at OJ props suggested trying that. 

So clearly ZO isn't a magic bullet for making all boats ski exactly the same. And like @Horton, if I had my way I certainly also believe that ZO algorithms could be modified to make the situation even better. And when the patents expire, which is only a few years off, a competing system could be developed that had more emphasis on consistency across boats and engines as well as other improvements. I think this goes to show just how much very tiny differences in the control systems can be felt by a skier. And the difference boat to boat with ZO is tiny compared to the difference I've felt skiing behind a PP Stargazer / zbox setup. I think it's also the case that some people are much more perceptive and / or bothered by these small differences. If you're not, and you're happy with zbox, that's great I think you're fortunate. But I don't think that means everybody will be happy with that setup. 

In terms of why the differences, I don't think it's fundamentally because of the different ZO tunes between boat manufacturers and engines. I think it's mostly caused by differences in transmissions ratios, propeller designs, and small engine tuning differences. But I also think it's the case that ZO's design goal was to make the system very easy to use for the end user and to almost completely eliminate out of tolerance passes. I doubt they had any intention to try and make the system feel as close as possible boat to boat and engine to engine. And with their near monopoly on the speed control market at the moment, there is absolutely no business incentive to spend money changing anything right now. 

I also may sound like I'm a big supporter of ZO and anti-perfect pass. But that's not really the case. I think the transition from perfect pass to ZO for tournament skiing was handled extremely poorly and did cause real harm to the sport. But I blame that less on eControls and more on how the governing bodies of water skiing handled the transition. eControls did in my view "invent" a better speed control system than what existed in the market before it. Especially in terms of end user usability and more consistently in reducing the occurrences of re-rides from out of tolerance passes. And I can't really blame them for using patent law to protect their innovation. Let's not forget that Perfect Pass was also protected by patents such that another manufacturer couldn't easily step in and replace them either. And if I'm not mistaken, PP sued ZO over infringing on their patents. In most cases similar to this in the industry, two companies like this with both valid but related patents, most often agree to cross license the intellectual property. And it's typically a win-win for both the manufacturers and the consumers. The governing bodies for waterskiing could have, and should have, taken a stand that they would only accept such an arrangement for the tournament approved speed control they would support. If they had taken this route, the transition wouldn't have been so detrimental to the sport, and we as skier would likely have an even better speed control system today. 

Years ago, I was a much bigger fan of looking for alternatives to ZO. But now I think we're past that in the market because ZO boats can be had for cheap enough IMO. Part of the reason I have that view, is because with the most recent downturn in the boat market. I think it's getting pretty hard to buy an older boat, convert it to ZO, and actually spend less money than buying 2008 - 2011ish ZO boat. Especially if you're really honest about making it an apples to apples comparison. By that i mean really having equivalent boats in terms of the condition of the interior and all aspects of the boat. Also, it's a different story if you also already own a Pre-ZO boat than if you have no boat and are getting into the market. 

I fully expect someone to bring up ... "wait didn't you post earlier that you're converting an 1999 bubble butt Nautique" to a modern engine and Zero Off. Yes I am, but to @Horton's earlier point, I know exactly why I'm doing it. It's not because I'm trying to create the ultimate slalom boat for anybody. Actually, I fully recognize the opposite. Given the current state of Zero Off, it'll probably ski differently than any other boat out there. 

I'm doing it because I just think it’s fun and interesting. I doubt I’ll even keep it in this configuration long term. I’ll probably rip the 6L Ilmor back out of it later for another fun project I have in mind. 

 

This is very useful insight, and very well spoken if may say so. I was impressed till I got to the 2nd to last paragraph, at which point I realized I have found a kindred spirit. You last paragraph describes me very well. I do these things be I enjoy a challenge and they hold my interest ... until the next interesting challenge comes along. 

That said, after talking to my racing industry friend, I think I'm going a whole different direction. With some good detailed input from guys like you and John, who seem to have a lot of experience with ZO on different boats, I believe that my friend may be able to adapt some of his existing (patented, thank goodness) technology to slalom boat speed control, but using Holley, or potentially Fuel Tech EFI ECU with a simply programmer on the dash (not unlike PP or ZO). And I could care less if what we come up with is ever mass produced, or if I'm the only one who wants to use it. I just want to do it because it's an enjoyable challenge to see if I can create a better mousetrap. If not, oh well.

BTW, I agree that it sounds as though ZO's ultimate goal was simply creating a user friendly system that would produce repeatable results, regardless of other factors. But again, that's why it's frustrating to me that they've made it proprietary to only their ECU's. I just don't get why they would want to limit their sales like that. Can you image how many more units they could have sold if they'd made it adaptable to all ECU's? 

[Scott Russell]

22 minutes ago, MISkier said:

@Scott Russell, I don't think the manufacturers are actually doing the tuning.  I believe that eControls is involved to produce the software image for them to load.  I think it is a collaborative process rather than an open interface that allows customization by either manufacturers or end users.  I think the software image is produced and managed by eControls to be provided to the manufacturers.  Hopefully, someone else with direct involvement in this process can comment.  I think there are skiers and drivers on this forum who are consulted for this tuning and calibration effort.

Wow, I'd be super interested to see what those BOS members had to say. I think they could definitely provide some insight. 

[Scott Russell]

15 minutes ago, MISkier said:

@Scott Russell, the patent office did not create the monopoly.  Both parties agreed to it as part of their lawsuit.  They settled with each other before it even got to court, if I recall correctly.  Part of that agreement was that eControls would not be able to market directly to boat owners with existing mechanical throttle or pre-2009 DBW setup.  So, PerfectPass received that market as theirs.  The re-power option you see with old boats was apparently not included in the agreement and is the workaround for those wanting true ZO in old boats.

Now, if a third party were to produce a new speed control system for either of these markets (new or old), then the viability and validity of the patents would come into play and the other company would have to defend such a challenge.  I see a new challenger as unlikely, as there are relationships within the boat manufacturer, speed control company, and water ski governing body that make the entry into the market difficult.

Thanks for that. That explains a lot and it also makes me feel way better about our government and them catering to the company with the best lobbyists. 

I suppose when you really get down to it, it really is two vastly different markets from a cost perspective. New boats being $130k+ when you can pick up really nice pre-2000 boats for under $20k. The customers really are a totally different financial demographic. 

[Horton]

@Scott Russell No. ZO is a tool set that is provided to the boat companies and then they find their settings.  See other post about the backend paramiters 

[Scott Russell]

29 minutes ago, Horton said:

@Scott Russell If your project looks like it will lead to a very cool restored old boat that performs within the norms of a modern ZO tournament boat, I want to promote what you are doing and follow every nut and bolt. I have endless passion around this idea.

If this project leads to a fun old ski boat hobby project that is cool but impractical as a modern training boat I will likely move these discussions to a different category so only signed in members can read it and more importantly Google will not index the content. I do not want to discourage your project but I do not want it to impact the larger focus of the forum.  The foundation of BallOfSpray is tournament skiing. 

I completely understand your position. At this point I haven't even bought a boat to do this with. It could also turn out to be just a fun old ski boat hobby project that isn't practical for tournament training. That said, it may be a good idea to move it to another forum for members only as you suggest. I don't want my personal interests to detract in any way from search engine optimization, or the image of the site to tournament skiers. Ultimately, I hope this project does indeed turn out to be something that EVERY person would want as an example of how to put together a budget minded boat that does meet the standard of being an outstanding training platform, but I don't have to tell anyone that that outcome is far from guaranteed. 

I hope I can still interact with members on BOS and pick their brains as this project unfolds, but I am respectful of your concern. 

[Scott Russell]

38 minutes ago, Horton said:

@Scott Russell If you last skied behind was a 1993 boat think of it this way.... How similar in performance is a 1993 Corvette to a 2023 Corvette? Pretty much unrelated except for the name plate?

The point that I keep trying to make is skiers have adapted to a very specific throttle response. Even behind the brands of boat we have today the difference between the boats is likely trivial from the outside but critical to skiers who ski tournaments. Any boat that tries to backward engineer the standard will likely be outside the norm.

As I recall there are 12 parameters in the back end of ZO that the ski companies can tweak for the different combinations of engines, hulls and props.   The skiing public does not have access to this dashboard and can not access these settings. 

The skiing public has access to a higher level / standard set of options. As an example when you go from an approved 4 blade prop to a an approved 3 blade prop you need to change that option. 

Point taken on the Corvette example. No question about it.

I also agree that the odds of trying to make anything outside the norm work to the standard tournament skiers are used to are slim. However, the norm is a constantly moving target, being improved on a regular basis. Though the odds of me pulling off putting together a boat that tournament skiers would want to train behind is slim indeed, I will likely still try just because I enjoy the challenge and have some of the technical skills necessary to give myself a better shot than that average DIYer. Will I fail? probably, but nothing great was ever accomplished by people who give up easily.

That said, I'm NOT making any grand statement claiming that I'm going to create the next holy grail of speed control, or that I'm going to put modern technology on an older engine foundation and challenge the lastest and greatest OEM technology. In the end it would be win for all DIYer's if I could pull that off, but I'm making no grand claims whatsoever, just so anyone reading this can clearly understand my position. I'm just a hobby guy playing with boats and stuff. 

I am encouraged to know that ZO is in fact not what I would have referred to as a "factory sealed unit". Those with the necessary software and passcodes can in fact "tune" ZO from what you said. I was really struggling to understand how they could put something in a box off of a production line and call it good with no way to tweak it after it is installed in a boat and yet end up with the amazing results they have achieved. Obviously that doesn't help ME, but at least now I know it's tunable. I almost thought they were Gods for a minute there haha. 

[Horton]

Whatever comes of this project I am for sure going to try to ski behind the 91 MC with ZO next time I go to Bell Acqua.