over hub or thru hub

[Lotus 50]

I've always assumed over hub was a bit faster, and that solo in my SS2000, just as good out of the hole

But then I see Aeneas is running a Hydromotive QIV OT on his SS2000 and I'm wondering over hub or thru hub. From the Hydromotive shop, I would have thought the T4-X would have been better.

 

[aeneas]

I spoke to Todd at Hydromotive about an allround propeller for the conditions I run in over here. I also wanted a propeller for learning to drive the boat. He came up with a special cut QIV OT and it is a fantastic handling propeller! I am comfortable at 94mph now and I think another 2mph is in it.

I also have an ET Lightning and a Mazco RE3.

 

[TMc]

I'm running one on my XR2002 and it drives good and it has the Allison cut on it. I don't know about all out faster but I can drive it faster with this prop than anything else I've tried.

 

[Lotus 50]

A stable 94 would be as fast as I'd ever want to run. At least for now.

 

[TMc]

Todd at Hydromotive is a nice guy and very good to work with you should give him a call I think he can get you what you want . He did for me and he has both over and over-thru.

 

[aeneas]

The Hydromotive QIV OT is not a full thru hub, more like a 3/4.

Here is 94mph. http://youtu.be/W2Ipk281rJI

I am not accelerating full because I am fiddling with the trim... :embarassed

 

[propmanjay]

Like Merc did with their new ET. Helps the blades from slinging!

 

[Lotus 50]

What is the gear ratio on the 200xs and how many rpm at 94? Salt water?

 

[aeneas]

Regarding the rpm I am not sure. I have a Mercury SmartCraft SC-1000 tacho that displays both analogue and digital rpm numbers. 6 660rpm is what the digital showed but on the analogue it looked more like +6 800. I trust the digital but Todd questions the rpm numbers.

The propeller is a Hydromotive QIV OT 28p cut. It feels like a stiff pitch, more like a 30 when looking at slip numbers.

Salt water. Water temp 10C (50F). Air temp the same. Wind 2m/s (4.5mph). Trim 5.7 where 5.0 is neutral.

The boat feels very light and like it could easily go a bit faster. I am just a bit careful as I had some scary moments early on...

Here is a pic of the Garmin GPS (81.6knots = 93.9mph):

I made a test with overlay where I had the speed in knots and mph in the clip. Not these latest runs... I want to build a NMEA-ntework so I can record rpm, trim and speed to put in the video clips.

 

[h2oskiier30]

Max fart? WTH?

 

[aeneas]

Haha, fart is Swedish for speed.

 

[Lotus 50]

I actually knew that fart was Swedish for speed. We do fartlek training in my masters swimming program.

Do you have 1.75 or 1.87 gears in your 200XS? I've got 1.87 in my 225 PM so if you do as well, I can talk to Todd about a 28.

 

[aeneas]

I have 1.87 gears.