Differences between ZR4 and ZZ6

[wmccomis]

Hello everyone. I am looking at purchasing a GS22 and have come to the decision, like many, of which engine. I have read the forums on ZR4 vs ZZ6 and everyone's opinion. Obviously the ZZ6 is a hefty upgrade. I am in the midwest at low altitude and we primarily surf and slalom at 28 mph with a little wakeboard, but never with tanks full on our GS20. I have talked to others that have said this that and the other about the differences in performance. I think unless we wakeboard at 23 mph with full tanks, the ZR4 should have the power for us (correct me if I'm wrong). However, my question lies in the engine RPM. This is where I get confused about the differences. I understand the ZZ6 has larger torque to help with hole shot, but if I am surfing at 10.6 MPH, is there any difference in engine RPM between the two? I understand that both engines max out at the same RPM. So with the same prop, how can you achieve more power out of a ZZ6 than a ZR4 if the prop's max at the same speed? Using my knowledge of air density's affect on piston airplanes, I can see where the extra HP helps at altitude. However, at 700 feet above sea level, there isn't much loss of power due to less air.

The biggest thing for me is lower RPM's while surfing to it is a quieter experience.

On a side note, what do other's experience for RPM's when they surf? For me, at 10.6 MPH, full ballast, plus 6/7 people, I get about 3200/3300. Wondering if this is a similar range to others.

Thanks.

[NautiqueJeff]

The difference will be in the speed that you get to your RPM / set speed, and the amount of weight you can run, assuming the prop and v-drive/transmission gear ratio is the same. I would say that for your situation the ZR4 will likely do just fine.

That said, the ZZ6 will be noticeably more fuel efficient, since it is DI. I remember the first year I had a DI engine in my G23 I was very surprised at the difference in fuel usage over the older MP technology.

[teamolson]

The ZR4 in a GS22 will be a great. Short and to the point. The ZZ6 pushes the G at sea level so I can’t see paying extra for it on that boat.

[Interjon]

I have experience with GS22 and ZR4. Plenty of power. Only thing you may want to look at is will fuel savings pay for the upgrade over the period of time you intend to use and keep the boat. I doubt, but worth calculating. ZR4 burns some fuel!

[kylant]

if you ever go to altitude and surf, you will quickly realize the ZR4 is significantly under powered

[SANonTellico]

I ordered the ZZ6 for my GS22 for several reasons:
- Less likely to run low on gas when spending a long day on the lake
- Will need to carry slightly fewer gas cans down to the dock
- Don’t wan’t to be short on power when the boat is fairly loaded with people and ballast
- Not enough power is frustrating, too much power……doesn’t exist

[shag]

That last bullet point is awesome! And true! lol

[jameskent]

Hello all,

Seriously considering a GS22 for use at 3000 ft above sea level (Flathead Lake, MT) -- 70% waterskiing - 30% surf/wakeboard. Would take a long time to re-coup the $10K for the ZZ6 vs the ZR4 I believe. Any comments about why I should pay the $10K?

Also interested in comments about waterskiing behind a GS22.

[NautiqueJeff]

At sea level, the ZR4 is fine in that boat. Not sure how much the elevation will change that.

[bturner]

So these boats new are running what? $130K - $150K, maybe more these days? Since I'm not laying out the jack the next comment it easy for me to say but this is the way I see it.....

If I'm buying a new say, $125K boat and I had any doubt whatsoever that the power was not going to meet my expectations, I wouldn't hesitate for a second to purchase the $10K engine option. You see engine options on a boat are like choosing a larger attached garage or a deeper basement when you build a house. While they boost that initial purchase price up front they're next to impossible to add later without great cost and risk. If I couldn't afford both the other options I'd chosen and the engine upgrade, I would gladly forgo the fur lined lighted cup holders, the extra board racks or, dare I say it, yes the over the top sound system to get a boat that I have no doubt will meet my performance expectations. I'd look closely at removing options that I could possibly live without or add later. Screw up the engine option on a boat and it will be a constant reminder of your mistake. As far as better fuel efficiency gas goes.... sure, that's a great added benefit and consideration of the engine option but really, but if you can afford this boat does that really come into play as a make or break item? I will say if anything you'll probably get more for the boar with the engine upgrade in resale if that helps.

I've seen a lot of people add frivolous options to cars, boats and houses only to forgo items that they will miss and not be able to upgrade later. For me on a purchase like this I'd do the upgrade.

[kylant]

I can tell you from my experiences, the ZR4 is a dog at altitude. I had a GS20 with it at 6200 ft. The boat struggled to get up to and maintain surf speed with just stock ballast (no pro ballast) and 5-6 people in the boat. I worked with ACME all that summer and tried 3 different props. We got it better, but not great.
I did take the boat down to about 100ft elevation just to test, the boat was a completely different animal, it was just fine.

Since I live at altitude, I ordered the GS22 with the H6. I haven't looked back. That engine is a beast. I can move the boat completely weighted down with no issue