Scott Russell

V-drives are a blast! I've had two friends that raced them. There's definitely an art to manipulating the cavitation plates for the best performance. Not a boat type that you just jump in and hammer the pedal to the floor without some instruction. They sure look cool on a good pass with the whole hull out of the water with the front end looking like it would blow over at any second. The weird thing is that to ride in one, it feels really stable even though it looks pretty scary to watch.

There nothing wrong with bringing back old boats, or keeping them going and improving them. There are so many purely open water recreational skiers who could really have more fun with an old competition ski boat, but fear of getting one with rotten stingers scare a lot of people away from buying them. I see old Ski Nautiques and Master Crafts that have been left outside to rot for sale for $1000 or best offer. It seems a shame to let them die. It does my heart good to see your dedication and determination to keep a boat alive, and even improve it. I'm just getting back up to speed on where things have gone since I got out of skiing at tournament level 28 years ago, and I'm just learning that Master Craft stopped putting wood in their hulls at some point in the 80's. Is that true? If so, I'm surprised there are LOT more of them on the water today. I'll be very interested to see how your composite stringer project goes. I'd bet there are a lot of people who would rather do that than put wood back in the boat knowing it will only deteriorate again over time.

So the 6L was too responsive with ZO in the lighter boat? Did it time ok? Or was it too quick through the course? That sounds like situation where you need access to those back end settings you mentioned earlier. Do you think that would have helped? Or was it just too much power for the weight of the boat?

I'm trying to learn how much of the new tournament boat's performance is Zero Off and how much of it is the additional power. I see the word response used a lot to describe the performance of the new boats with Zero Off. Is it Zero Off, or the responsiveness of Direct Injection? I don't know, but I'd like to figure that out.

The goal in the end would be to have a very nice, comfortable boat that is good enough that tournament skiers would want to ski/practice behind it. I just want to be sure I start with very nice, fairly pristine example. So far, a lot of the boats you mentioned that I find for sale are basically worn out. Regardless of the boat, I think in the end you'll find that I'm doing something that hasn't been done. It's a repower, but not the typical "go buy an engine with more power to replace the old one" kinda deal.

Thank you for the kind words Kevin. I love tinkering with mechanical things and enjoy a good challenge. As long as John lets me hang around, I'll share progress once things get started. As I've said before, this is just the planning stage. I still haven't 100% settled on a boat I want to do this with yet. but I think I have it narrowed down to either a 91-94 MC, or a 97-01 SN. I'm looking around at boats now, but the reality is, I won't be buying till after the first of the year. Hopefully there are some nice older boats to choose from then. I'm definitely not going to buy a rough boat that needs a lot of hull, interior or peripheral equipment work. The perfect scenario would be to find a garage queen with a blown engine, where the boat is mint, but it needs a power plant. It'll never happen, but a guy can dream.

Did you feel like that prop and the higher RPM helped to keep speed more stable without ZO intervention? or no noticeable difference?

When talking about the response time difference between a direct injected engine and a port injected engine, it got me thinking so I did some quick math. At 4K rpm, a GM LS engine would have an intake port air velocity of roughly 150 feet per second. In the average V8 port injected engine, the injector nozzle is roughly 6" from the intake valve. So the fuel has to travel 6" before it can be combusted. At 4K rpm the injector will fire 33 times per second. The math suggests 66 times per second, but keep in mind that in a 4 stroke engine, combustion only takes place every two revolutions of the crankshaft. At 150 feet per second air velocity, the fuel from the port injector takes 1/300 of a second (or .00333 if you prefer) to get from the injector to the combustion chamber. A direct port engine fires the fuel directly into the chamber. Doesn't sound like much difference, does it? If it takes 16.95 seconds to get through the slalom course on a pass, a single injector fires 559 times during the pass. That equates to a 1.86 second total time delay vs direct injection over the course of a pass through the course. That sounds like a huge number when you are only talking about 16.95 seconds to complete the run, doesn't it? Well that would depend upon how much of the 16.95 seconds it's making fuel delivery corrections. It's making them all the way through the pass, then I can definitely see why response would be better with direct injection. I've never ridden in a boat with ZO, so I've never been able to hear what the engine is doing first hand, but I'd bet it is correcting quite a bit of the time. Before I did the math, I was questioning if Direct Injection was really making that much difference in response. After doing the math, assuming it corrects a LOT, I would think it makes a pretty noticeable difference to a short line skier over port injection. This is when it would really be great to hear from some port injected engine ZO boat owners, vs the newer DI engine ZO boat owners. No amount of data will override real world user experience.

Am safe in assuming this the boat that you put a 6.0 with ZO into? If so, how did they compare? I know you didn't (couldn't) have ZO on the 454, but as far as pulling power, how did the 6.0 compare to the big block?

Well, it's at least encouraging that I wasn't completely off base thinking the difference in torque at the rpm the engine would be in while in the course was making a difference. I'd love to hear from some people who have pre-direct injection engine boat with ZO and see if they experience the same response without direct injection engines as the newer engines that do have it.

That wake looks fantastic for the rope length for sure. I really think the recreational skier of a lower financial demographic has been left behind years ago by the boat manufacturers. Very few people can afford to just go buy a new boat these days, and the crazy LONG term financing is just encouraging reckless spending. The interest on those loans will kill your soul if you look at an amortization calendar.

I look forward to hearing your feedback when you do. That project excites me. I almost bought a new 454 Pro Star in 1988 (it may have actually be a 89 model, but I'm not sure). I loved that hull. The teal and green colors on that boat were my favorites.

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.

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.

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.

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

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?

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.

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.

https://perfectpass.com/product/stargazer-three-event-upgrade Looks like they offer the above upgrade for DBW

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.

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.

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.

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.

I saw those. They are pricey, but you get what you pay for. They are the nicest I've seen so far.