mid cabin - floscan preliminary results

[BobCT]

I got my floscans and racors installed and did a quick test run on Saturday. I have an issue with the stb side sensor, the needle is sweeping up/down and I need to troubleshoot. For now, I'm doubling what I get on the port side which seems to work flawlessly. I'm "assuming" the stb side will be the same or close so take these for what they are.

Readings are from Garmin GPS, upgraded trim tabs, roughly 1/2 tank fuel and water, three people.

2,000 RPMS/8.8k/12 gallons/hr
2,300 RPMS/10k/16 gallons/hr
2,900 RPMS/15.7k/26 gallons/hr
3,100 RPMS/17.2k/32 gallons/hr
3,300/18.4k/38 gallons/hr
4,000/22.9k/60 gallons/hr

I didn't really spend any time with the trim tabs so these can be tweaked a little. No surprise, you can see when the secondaries open over the 3,000 mark.

My bottom paint needs to be stripped (lots of layers) so that'll help for next year.

I've gotten to 4,100 WOT. That seems to be about the max on the mid cabin with the original 3 blade props. I think a couple of people have gotten to 4,300 but in the surveys I found on-line some of the higher readings noted about 150 RPM difference in tachometer error.

If you have a mid cabin and are getting around 4,000/4,100 you're pretty close to the top end. In the video that RWS posted they posted 4,100.

CRUISING SPEED (rpm/mph):
3300 / 20.9

TIME ON PLANE: 5.8 seconds

TOP SPEED (rpm/mph):
4100 / 26.8


I'll post some better results once I get the stb side sorted out.... hopefully before the season ends.



Bob

[S.A.M.]

Bob,

Those numbers look great. With out graphing it, 2900- 3000 is the best cruising speed. You are running about the same as I am with 4 blade wheels. That could account for the larger trim tabs you installed.

Makes me wonder about the combination of larger trim tabs and 4 blade wheels..

[BobCT]

I wish I had the floscans installed with the old tabs AND knew how to use them.

I ran the boat bow "up" for a long time because it created the smoothest wake and so I thought least amount of drag.

Paying more attention to the GPS and floscans (for one day) I can see an increase in speed by having the tabs further down. The wake looks aweful, like you're dragging a dozen tires but I assume the instruments don't lie. It's also a much more comfortable ride being able to see over the bow.

I don't know the before/after with the new tabs. I know it's better but don't know by how much.

I'm thinking the same as you are.... does your 4 blade change equal my trim tab upgrade? Do both give you even more?


Bob

[S.A.M.]

With what you gained with the TT and I gained with the 4 blades, I think the combination will give us our optimum performance.