G23 450 vs 550

[powercorps]

I currently own a 2008 x-star with a 350 hp engine. With the ballast I use, it no longer planes out effectively. If I were to take a new direction and go for a used G23, will the 450 get on plane with ballast full and boat loaded in a reasonable amount of time? Will I wish I had the 550 down the road like I wish my xstar had a bigger engine now? For price reasons, I will probably have to stick to the earlier model years. Also, are there any other things I ought to be considering with respect to these two engines (maintanance, fuel, etc.)? Thanks

[Farmer Fred]

There’s a great thread on here about this exact topic, but you pose a great question. If you go used, stay 2016 or newer with the 450 engine. That way you’re buying the more modern direct injected engine that’s easier on fuel and has a flatter torque curve. It runs on regular unleaded. The 550 would be a great choice if you run at high altitude, but I’ve read that it consumes more fuel. Being supercharged, it also requires premium unleaded. The other benefits of the 550 are closed loop cooling and no catalytic converters. Other considerations are your primary uses. Will you surf or wakeboard more? If you bought a boat with the 450 and needed a little more power, there are several prop options available that are cheaper than the 550 upgrade. Hope this helps.

[powercorps]

OK that is helpful info. I doubt i will be able to make the payments if the boat is much over 100k. Unless I get lucky I don't see myself ending up with something that new. If i go pre-16 should I stick to the 550? Ill look for that old thread too.

[skiinxs]

Farmer Fred I totally agree that the newer direct injected 6.2 (450hp) is an awesome motor that makes torque everwhere due to the variable valve timing among other thiings. I disagree about the regular unleaded comment though. Although it will run on regular unleaded with no damge, it will take off a lot of timing advance to do it and will not make nearly as much hp as it will on 93 octane.

[Farmer Fred]

skiinxs It is my understanding that the old 450 (2015 and prior) was basically the same as the ZR409 but it was tuned to run on premium fuel and would make 450 hp if you ran premium. I had a lengthy discussion with my Nautique dealer about fuel requirement for the H6 450, and he said that it is designed to run on regular unleaded. Here in CA regular is 87 octane. He said the H6 can be run on premium fuel, and it won't hurt anything, but there is no advantage to it like in the old 450. Theoretically, the variable valve timing in the H6 should account for the lower octane and produce peak performance across a wider rpm range. The older 450 did not have that ability. Anyway, just my 2 cents.

[skiinxs]

Farmer Fred He is wrong. I have two full years on H6's, and as I said, they will run fine on 87 octane and not cause any damage, but make LOTS more horsepower on 93 octane. I could supply Diacom files with 87 octane and 93 Octane showing no detune on 93 octane and significant detune on 87. By significant I an talking about 15 degrees of spark retard and approx. 7 mph reduced top speed. By the way, my last 2 - 200's would run 53 mph with the 6.2 (H6) on 93 octane, rpm limited by the prop. (12.5X15.5 4 blade .150 cup)

[Farmer Fred]

skiinxs That is good information to have, so thanks for responding again. I actually plan to run my new H6 on 91 octane fuel because that’s what I have in my ranch storage tank, so it sounds like I’ll actually get better performance than if I ran 87. I wish PCM was a little more forthcoming on their website about engine details. Happy skiing!

[skiinxs]

Farmer Fred Also remember that gasolene loses around one octane point per month of storage. I think stabilizer may help that but you should keep that in mind when you are storing for long periods. I only add a couple hundred gallons at a time in my lake 500 gallon tank unless I have a tournament or "Swervin' Weekend" coming up that will cause me to use a lot more gas. My goal is to not let my gas get more than a month old. I agree they could spell it out a little more clearly. The statement in the owners manual is a little vague: "NOTICE: These engines have been calibrated to operate on 87 octane fuel. PCM’s engine control module incorporates Adaptive Learn Technology to ensure optimum engine performance is obtained when using fuel rated higher than 87 octane. Use of fuels lower than 87 octane will result in reduced performance, could cause engine damage and should be avoided."

Another point to keep in mind is that once they have gone into detuned mode running 87 octane, just switching to 93 octane on the next tank doesn't immediatly get your horsepower back. It will take a while for it to re-learn, but you can hurry that along by disconnecting the battery for a few minutes after you put in good gas to force an immediate relearn,

[Infinity]

Are you saying regular ethenol gas loses around 1 octane per month, or all gas? I know the "shelf life" of ethenol gas is not good, I dont put that stuff in anything except my vehicles that I use every day. Boat, lawn mower and everything else gets ethenol free fuel, I am lucky that its readily available in my area still.
I ran 87 octane ethenol free fuel in my ZR409 engine all last summer.....summer before I ran only 91-93 octane that I got on the lake (actually cause some said similar stuff that you did about how no matter what manufacture says, higher ethenol is better for the engine). I have always tracked my average GPH, my rpm at surf speed, etc...I saw zero difference in GPH, rpm or performance last summer running 87 all summer. My top speed was also exactly the same. Filling up the boat away from the lake saved me $2 gallon which put around $1k back in my pocket last summer and since I trailer anyway, it was no extra work doing it that way. I surf and don't need to go fast, so it works for me.
Not saying you are wrong in the data you shared, I just personally noticed zero difference with my boat. Maybe the H6 is different

[thedude]

To the OP, any 2014+ (2:1 gearbox) 450 will plane out quick with stock ballast and people on board. It still does well with added ballast and people. 2013-2015 (1.48:1 gearbox) 550 will run fewer RPM's all things being equal, but use a little more fuel. 2016-2018 (2:1 gearbox) 550 should be re-propped to get RPM's and fuel use down a bit. The 2:1 gearbox in the 550 is overkill with the 17x17 prop that comes stock. This all assumes you are around 2000' elevation.

The 2015 450 is a good option with the electronic shift throttle, and would save ya about $10-15k vs. a 2016 looking on onlyinboards, keeping you around the $100k mark. I think the throttle update was a huge improvement over the '13-'14.

[skiinxs]

Infinity I'm no expert on gas shelf life, but I have heard the one octane point per month number as a rule of thumb from several times over the years, maybe an expert can weigh in here. I am very envious of your access to pure gas, I wish I could get it. No argument on 87 octane working fine on the 6.0, I have had twelve in various iterations, 375HP, 390 hp and then the 409 hp the last few years before the 6.2 came out. I never ran anything other than 87 in any of them and never saw any detune causing timing retard in any of them. (and I do check by pulling reports with my Diacom) The 6.2 is different, probably the higher compression, but they make more power on 93 octane. It is interesting that the owners manual on my Chevy pickup with a Direct Injected 6.2 (same engine as PCM 6.2) is a little less vague but acknowledges it will make more power on premium. Here is the quote: "Premium Recommended Fuel Use premium 93 octane unleaded gasoline in your vehicle. Unleaded gasoline with an octane rating as low as 87 may be used, but it will reduce performance and fuel economy. See Fuel 0 311." In contrast, the 5.3 in the same manual states: "Regular Fuel Use only unleaded gasoline rated 87 octane or higher in your vehicle. Do not use gasoline with an octane rating lower as it may result in vehicle damage and lower fuel economy. See Fuel 0 311" The direct injected 5.3 runs a lower compression ratio. I can also tell you that the 6.2 is a really strong motor in a chevy pickup, but I have only run 93 octane in it. The nice thing about the new direct injected 6.2's by PCM is that they will run fine on 87 octane with no chance for damage, they just make less horsepower. I don't need top speeds in my Ski Nautiques, but really strong 35mph jumpers can actually use all 450 hp,, some could benefit from more, especially those who jump in slalom mode on the Hydrogate, which is why I also swap props to my 3 blade jump prop for the jump event in tournaments.

[Infinity]

Good info to know, Thank you....nice that you have Diacom available to you to confirm that stuff. I have looked at the H6 in a couple new boats I considered upgrading too. Think I will keep my 2014 a while longer tho, been a great boat and looking at minimal depreciation over next 2yrs compared to going new again and starting it all over again.

[powercorps]

Just to be clear, the electronic throttle added for 2015 doesn't change available power right? Its just a nicer feeling throttle? Is it worth searching for a full year newer boat when I can get the 2:1 transmission in the 2014's?

[skiinxs]

The 2015 throttle (which added fly-by-wire shift to the the fly-by-wire throttle) was a huge improvement. If I was looking at used boats, I would bump up to a '15 and later for that reason alone (or a '12 or older) The throttle was changed in 2013 to incorporate fly-by-wire throttle only and was still cable shift. This was a "less than optimal" box. In 2015 a redesigned box was implemeneted that added fly-by-wire shift and has been the same ever since. That is a GREAT box. I have no idea about the transmissions in the wakeboard boats.

[GMLIII]

The 2015 throttle (which added fly-by-wire shift to the the fly-by-wire throttle) was a huge improvement. If I was looking at used boats, I would bump up to a '15 and later for that reason alone (or a '12 or older) The throttle was changed in 2013 to incorporate fly-by-wire throttle only and was still cable shift. This was a "less than optimal" box. In 2015 a redesigned box was implemeneted that added fly-by-wire shift and has been the same ever since. That is a GREAT box. I have no idea about the transmissions in the wakeboard boats.

Your Nautique 200 with an 450 H6 engine has got to be a rocket ship. I can't imagine, my G23 has an H6 engine and weighs +/- 3,000 lbs more than the Ski Nautique