Black Pearl II Hydro - 2020

[ray schrauwen]

Lol... I can tap the CF but not as nice as aluminum. I'll just use my nuts :)

[lohring]

Consider that the latest motors in P limited hydro are RATED at 3,000 watts. That's around 4 hp. The most outrageous power claims for 7.5 cc nitro engines are less than that. The NAMBA SAW record for a sport 40 is 81 mph set in 2001. The two lap record for sport 40 is 51 seconds. The P limited SAW record is 80 mph set two years ago. The two lap record is 46 seconds. The turn fin loads should be similar.

My sport 40 is 36" long. The P length limit is 34" Maybe it's time to rethink this to avoid running fast, hard to control little boats.

Lohring Miller

[ray schrauwen]

That's partly why I'm running my 34" Pearl in Limited class so that it stays completely planted.

[ray schrauwen]

What prop can I start with on this 34" hull, Huff Leopard 3674 rewind chopped 2300kv, Castle XL2 converted esc, 6500Mah or more...?

1814?

[lohring]

I ran an ABC 1717-19-38 on my outrigger with a motor with similar KV to yours. I'll be running a TenShock with a 2680 KV in the Black Pearl so that prop may be a little big. I can fit two 5000 mah 4S batteries in parallel in it with a Castle MAMBA Monster X ESC. I'll talk to Brian Buaas to see what he thinks.

Lohring Miller

[Reesor@work]

That's partly why I'm running my 34" Pearl in Limited class so that it stays completely planted.

Trust me - you can and will blow that hull off in P Limited. That's huge Kv in that hull for P Limited. I'd start 'small' with props and work your way up - each iteration and prop type will require some trimming. Terry would be the guy to ask regarding a starting point with that Kv. His Pearls are glued to the water and run obscenely fast. I can't believe the props the Michigan guys run in P Limited racing. Lohring is correct - these little motors generate crazy power.

[TRUCKPULL]

Consider that the latest motors in P limited hydro are RATED at 3,000 watts. That's around 4 hp. The most outrageous power claims for 7.5 cc nitro engines are less than that. The NAMBA SAW record for a sport 40 is 81 mph set in 2001. The two lap record for sport 40 is 51 seconds. The P limited SAW record is 80 mph set two years ago. The two lap record is 46 seconds. The turn fin loads should be similar.

My sport 40 is 36" long. The P length limit is 34" Maybe it's time to rethink this to avoid running fast, hard to control little boats.

Lohring Miller

3000 W = over 4 HP

Larry

[lohring]

3000 W = over 4 HP

Larry

OK it's 4.023066267 hp(I) or 4.078864852 hp(M)

Sounds like 4 hp is pretty close.

Lohring Miller

[ray schrauwen]

Trust me - you can and will blow that hull off in P Limited. That's huge Kv in that hull for P Limited. I'd start 'small' with props and work your way up - each iteration and prop type will require some trimming. Terry would be the guy to ask regarding a starting point with that Kv. His Pearls are glued to the water and run obscenely fast. I can't believe the props the Michigan guys run in P Limited racing. Lohring is correct - these little motors generate crazy power.

Thanks Steve. I hope you're doing well.

[ray schrauwen]

I ran an ABC 1717-19-38 on my outrigger with a motor with similar KV to yours. I'll be running a TenShock with a 2680 KV in the Black Pearl so that prop may be a little big. I can fit two 5000 mah 4S batteries in parallel in it with a Castle MAMBA Monster X ESC. I'll talk to Brian Buaas to see what he thinks.

Lohring Miller

Thanks Lohring!

[T.S.Davis]

Terry would be the guy to ask regarding a starting point with that Kv. His Pearls are glued to the water and run obscenely fast.

My Pearl most certainly is not glued to the water. haha.

I'm super hesitant to recommend props without seeing a boat run myself. If I recommend what I really think will work and it bakes a motor........well that sucks.

Best to start small Ray. I think Don runs 17 series props on that motor. I would start around 1814-17-45 maybe. Do the heat check deal every 2 or 3 laps. Remember too that you may/might/maybe need to make strut adjustments for diameter and even rake. An 1814-17-45 vs an 1814-19-38 might need an adjustment. Tiny tiny adjustments are the difference between flight and fast on these. Like .5mm at a time. This is true of all the Pearls in my experience.

[ray schrauwen]

Thanks. I have a 1615 I can try first and some proboat 1716 SS props.

[T.S.Davis]

The 16 likely wont plane.

[ray schrauwen]

LOL... thx again.

[lohring]

Brian thinks an ABC 1715 is good for my Black Pearl with the TenShock motor. We'll see.

Lohring Miller