First Run w/38x63

[Drag Boat Bob]

The 38x63 performed better than the 38x55 (at least for me). Ride was a bit more loose (which I am looking for), but still not anything close to wild. GPS - 47.5mph.

It handled crossing the wake well without getting out of control. It is also much better at acceleration out of the turns. It has better bite on launch also. No torque roll (hospital hop or whatever you guys call it) except momentarily in rough water.

Temps are still not an issue, but then this is what I would expect at this load level. I expect the L40x57 and M445 to make temps a concern. I will most likely try the L40x57 next and I base that solely on what I have read here, as I am an old 2-blade guy.

I still have more testing to do with this prop.

More to follow...

[bigpapa]

chine walk lol good luck keep us posted

[Drag Boat Bob]

chine walk lol good luck keep us posted

Chine walk...ok. From my old drag racing days that term was only associated to boats with a chine, like flatbottoms. However, I am ok with that.

Odd thing today. While charging my batteries one of them appeared to secrete a clear fluid. Only a very small amount, but it was enough to cause the seal-wrap to start to come off (approx 1/2 in from corner).

Both cells charge ok and are equal. I balance every time at .5c. Has anyone experienced anything like this?

I think I will call MaxAmps when I get back to my home.

[Drag Boat Bob]

I shifted some weight and tightened down everything and made another run. The boat rode looser than before and I could hear the prop getting air when crossing a wake. Overall I am happy with this prop. GPS - 48.6mph.

I might make one more run (with adjustments) before moving on to the L40x57.

One thing for sure, I need more than one set of batteries.

[bigpapa]

picked up mph thats good temps were ok

[TCR]

What is your strut depth w/ the 38x63?

[Drag Boat Bob]

picked up mph thats good temps were ok

The motor temp was 126 and the ESC cap was 112. Deans were 119. These batteries have never heated up (always <90). Could be that with the exception of the boat's first run (all the way to the LVC) all are relatively short runs.

Actually I don't know what a "reasonable" run time is. I seem to be putting back around 2500 mAh back into the batteries (MA 6500 mAh). I'm sure someone can say if this is "reasonable".

I hope to get more runs in before I have to leave this lake (on vacation), but with it being the weekend (and leaving Monday) more people are showing up with the big boats. We'll see...

[Drag Boat Bob]

What is your strut depth w/ the 38x63?

I started at the stock depth of 15/16" and with the prop changes, needed to drop to 1". Have not needed to drop any further as the ride wasn't excessively loose.

[Drag Boat Bob]

Battery Anomaly

I realize that 4 consistencies do not constitute empirical data, but it is enough for me to conclude that there is a problem with one of my batteries. There is a 3+ mph difference with a particular battery series. Simply put, with no other changes to the boat, the speed changes when one of the batteries is used on a particular lead (1st in the series connection).

I am now certain that one of the batteries is leaking a clear fluid on discharge. I will take this up with the manufacturer when I return home.

I have decided to delay testing of the L40x57 until I resolve the battery anomaly.

The L38x63 is a great prop and I will continue having fun with it for now.

Thanks to all who provided guidance. I am learning at an exponential rate.

[Drag Boat Bob]

Last Run

I decided to get in one last run before leaving this lake. Water conditions were absolute glass and no wind. I think I found the sweet-spot setup for this prop. GPS = 50.2 mph.

It was a 1.4 mi. run and leaky battery or not, this is the best I have reached with this setup. Temps: Motor 121, ESC Cap 119, deans 108, batteries 86 & 94.

I really love this prop… now if I could only drive…

I’ll be testing the L40x57 in a couple of weeks.

[bigpapa]

the 38x63 great speed, no chine walk at all ??????

[Drag Boat Bob]

the 38x63 great speed, no chine walk at all ??????

Only when crossing its wake and then it subsides to a perfect sponson skip. It looked as close to a perfect ride as I can explain. I am sure the water conditions had something to do with it.

I have found that placement of the GPS has been crucial. It has made the difference of 4 mph. I believe that 'balance' is key to the ride.

Lifter props, do just that "lift" the back end. When the balance is too far back or forward it hurts performance.

[bigpapa]

i here ya tks for the testing info and happy racin

[Brushless55]

Only when crossing its wake and then it subsides to a perfect sponson skip. It looked as close to a perfect ride as I can explain. I am sure the water conditions had something to do with it.

I have found that placement of the GPS has been crucial. It has made the difference of 4 mph. I believe that 'balance' is key to the ride.

Lifter props, do just that "lift" the back end. When the balance is too far back or forward it hurts performance.

where do you place your gps ?

[Drag Boat Bob]

where do you place your gps ?

I ended up with it as far forward as I could get it, but still in the back of the boat.