What prop should I get? Lucas oil

[TheShaughnessy]

an m445 or an x 642 are pulling upwards of 80 amps, which an AQ motor can handle in 5 second burst. Not really sure how you guys are running 4 + min with an m445, I pull over 2500 mah after a 2 min race, 2 more min and my batteries would be pissed and motor wires would start de soldering. Im in the 45-48 mph range. certainly not 54. I suppose it could be done but I put a lot of importance on actually finishing the race so maybe I'm not running as loose as some of you guys .

[SD Eracer]

Our group doesn't do races, but we are pretty much on full throttle the whole 4-5 minutes. The 54 mph is with a 2030kv motor, we are hitting 47 mph with the 1800kv.

For must of us, the X642 has been our "go to prop" either on 4S or 6S applications, we haven't seen any issues with it. I've noticed very little performance differences between the X642, M445 or Grimracers 42x55 in terms of speed and consumption.

[MADRCER]

Ran it again with the strut bushing freed up and lost a mph only got 37 with x642. I guess it is a bad/weak motor..

[SD Eracer]

That's the only thing I can think of, we did a shake down run of a new Motley Crew with a rather dull barely balanced Grimracer 42x55 prop and it did 45 mph with some old Turnigy 5000mah batteries.

This was out of the box, other than putting on an OSE flexshaft and brass prop, it was completely stock.

If your boat is still under warranty, I would give Aquacraft a call, they are pretty good about making sure the boat is right.

[MADRCER]

Thanks for your help! I will contact them it is only 2 weeks old and been ran/tested only 4 times. The motor in mine when I spin it by hand it seems to have double the resistance from the magnets than my Pro Boat 2000kv motors that I have on my Geico and zelos twin. Does this seem normal for AQ motors?

[SD Eracer]

It is a 6-pole motor, it should have more resistance when turning than your typical 4-pole motors.

Just to confirm, after you arm the boat (which requires a throttle calibration), do you touch the throttle trim on the radio by chance? The throttle trim on electrics should be set at around the 2 or 3 o'lock location, and will require a throttle re-calibration anytime they are adjusted.

[MADRCER]

No, I never touched the throttle trim after the ESC has been armed. Only the steering trim.

[SD Eracer]

Gotcha, then it's the motor or ESC.

Either the motor isn't giving out the power it should, or the ESC isn't allowing it to.

This is assuming your batteries are working fine.

[MADRCER]

Ran the boat yesterday with a 2030kv in it while I am waiting on my replacement 1800kv and hit 45.1 mph with a x442 mild s&b. Am I in the ball park with this prop and set up? I didn't try to re adjust strut and try the x642 again during this outing but it still looked like it was flat and a little too wet. Probably could raise the strut a mm or so and pick up a little. What y'all think? If I am getting 45 with the ESC I assume it is ok?? What ya'll think? The strut is flat and touching the table when the rear sponsors are pushed down while touching the table. See video

[SD Eracer]

That's about right with a 442, looking pretty good actually.

I would leave your hull settings the same, especially if you plan on using the X642 prop, the temps and consumption won't be that much higher.

But the danger with the X642 is that it will bump you up to 50-54 mph range immediately on the 2030kv motor. Which will increase that hull flipping over more easily, which could damage that stock hull at that speed.

To prevent that, running a little more wet and/or also moving your batteries farther forward is a good idea. A forward portion of my batteries are slightly past the motor mount on my boat. I also run the front air deflector to further risk the chance of blowover.

Unlike other hulls, these Aquacraft tubs are not as easy to reinforce. My stock hull cracked almost from tip to tail after a 54 mph flip. I fixed it from the outside and it seems to have withstood several more bad flips, but the Lucas oil hull doesn't seem to be as strong as the stock Motley Crew hulls, even though the designs are the same.

Just be careful going forwards, try to avoid the hard flip on a stock hull.

[MADRCER]

Ok and thanks for your help! I'll post a video comparing the speeds with a x442, 42x55, and the x642 sometime in the near future. I got a Prather 220 coming and plan to try it as well. How do you think the 220 will perform against these props with this boat?

[SD Eracer]

Absolutely, happy to help! I'm not familiar with Prathers, most of my experience has been with Octuras.

However, since it's hard to find certain brass prop sizes (45mm for example) in left and right turn for my HPR 115 and other dual drive cats, I may start looking at other brands. The CNC props sold in L&R configurations rarely survive a few packs through a big dual drive cat on speed runs.

[MADRCER]

I ran the boat today with my replacement 1800kv Aquacraft sent me and hit 41.6 with the x442 strut was set the same exact way as the x442 45mph run. I ran in a different lake so the water conditions werent exactly the same as the previous run, but close to the same. I ran it early in the morning and I guess the Humidity in the air made my hatch seal tape come loose (never had this problem ever before) and the top blew off. However I was able to recover it but not what I was expecting to be doing at 6AM in the morning on my way to work. Lol. Anyone else have this problem with the tape not sticking early in the morning? Well it stuck good until the boat was in the water on the second pass it flew off. I even put it on while the boat was still in the seat of my truck before the boat ever was taken outside.

[SD Eracer]

Excellent, that's about right with the 442 on a 1800kv, I can see 45-47 mph when you switch over to the 642. Temps and consumption will hardly be noticeable, but the speeds will be.

As for tape, I highly recommend you use Harbor Freight Black Electrical Tape, the one they sell at $5 for a package of 10.

They have just the right amount of adhesive for a good seal, but not enough to leave residue or damage your paint/decals. One of the few things Harbor Freight sells that I could actually recommend buying.

Also, since you get so much tape for so cheap, you should double up on how much you apply for better insurance. Make sure to always bring a dry microfiber towel to dry the canopy area before you apply the tape.

[MADRCER]

Thanks! I will try the 10 Pack at HF. I normally use the Hockey tape from Kinetic and it sticks real good but not this morning. I got another x642 coming from Dasboata. My orginial from Rocket city decided it wanted a divorce from Miss Geico and left her for some other fish in the sea last run. Lol

[SD Eracer]

I will try the 10 Pack at HF. I normally use the Hockey tape from Kinetic and it sticks real good but not this morning. I got another x642 coming from Dasboata. My orginial from Rocket city decided it wanted a divorce from Miss Geico and left her for some other fish in the sea last run. Lol

I love Hockey Tape, but I prefer to use it on my old beater HPR that already has a beat up finish. That boat of course uses lock screws, so the tape is only for water proofing, but at 80+ mph, you want hockey tape.

But just remember that hockey tape will eventually destroy your finish. Some people will apply a clear tape over the area that's semi-permanent. So when you apply and remove tape constantly, it's only hurting the tape and not the paint under it.

As for Dasboata, they are fantastic. I will mention though that Octura props are some of the easiest props to sharpen and balance. They have some rough flashing that's easy to remove, and they are pretty sharp to begin with. I can usually S&B a X642 in about 20 minutes.

[MADRCER]

Done a few test with different props and the replacement 1800kv motor if anyone is curious on the speed differences between them on my set up. No strut adjustments were made only prop swaps and the test were all done on the same exact day and water conditions (average with some mild chop). The boat still has more in it but I wanted to find out which prop I liked best and be faster for me then I will fine tune the boat for maximum speed without blowing over.

Batteries 2x Zippy 2s 5000mah 45c
42x55 Grim 43.6mph (sharpened and balanced by me). This prop would probably get 44.5mph with the nano tech 6.6 batteries since they traditionally pull another mph than my others
Prather 220 s&b 39.3mph This run was on the packs that I had already ran 3 laps on with the 42x55 prop, so maybe add 2mph more if they were fresh charged batteries. This prop got out of the hole very well with very little cavitation if any at all.

Batteries 2x Turnigy nano-tech A-SPEC 6600mah 2S 65~130C (these batteries always log one mph more than any batteries I use in this boat)
x442 s&b 43.1 mph

still waiting on my x642 prop to test.

[JJ1TRXSAton]

Very cool info MADRCER. What gps tracker did you use? My friends get different results using the dynamite speed tracker and the Garmin ones. MY MC likes running with the X642.

Just saw your vid and saw the Garmin gps unit.

[MADRCER]

Thanks! I used the Garmin Forerunner 101 on all these test. What speed are you getting out of the x642 and on what motor?

[JJ1TRXSAton]

Hit 49 twice with the X642. Using the Giant Power 2S 6500mah 65 - 130C lipos. It does like to blow over sometimes. So far no hull damage.

[MADRCER]

Nice! 1800kv or 2030kv?

[JJ1TRXSAton]

The 1800kv. Going to swap in a different motor my friend has just to try it out.

[MADRCER]

Finally had time to run the x642 prop so I wanted to update my previous post with the speeds, if anyone is still curious on the differences see below. I believe I could raise the strut just a tad and pick up another mph but I am happy with it the way it is for now. However, I may try a M445 soon to see how it stacks up with the others.

Done a few test with different props and the replacement 1800kv motor if anyone is curious on the speed differences between them on my set up. No strut adjustments were made only prop swaps and the test were all done on the same exact day (except for the x642 test) and water conditions (average with some mild chop). The boat still has more in it but I wanted to find out which prop I liked best and which one would be faster for me so I can fine tune the boat for maximum speed without blowing over.

Batteries 2x Zippy 2s 5000mah 45c
42x55 Grim 43.6mph (sharpened and balanced by me). This prop would probably get 44.5mph with the nano tech 6.6 batteries since they traditionally pull another mph than my others
Prather 220 s&b 39.3mph This run was on the packs that I had already ran 3 laps on with the 42x55 prop, so maybe add 2mph more if they were fresh charged batteries. This prop got out of the hole very well with very little cavitation if any at all.
x642 (DASBOATA) 44.3mph

Batteries 2x Turnigy nano-tech A-SPEC 6600mah 2S 65~130C (these batteries always log around one mph more than any batteries I use in this boat)
x442 s&b 43.1mph
x642 (DASBOATA) 45.4mph

[SD Eracer]

Looks good, I think you have a few more mph in there with your strut settings and battery location.

Adjust one item at a time (strut positive or battery farther back) and check the speeds after each adjustment.

I figure 47 - 48 mph with the 1800kv and X642 should be consistent once you get the settings dialed in.

I would avoid going over 50mph with that hull, it's easy to break a seam over that speed with a hard flip.

A couple of years ago my Genesis cat was doing about 70mph before I lost connection and it hit the embankment and flipped head over tail several times on the ground before knocking a guy off his lawn chair and finally settling on the grass. I had zero structural damage, just a broken rudder break bolt. This was because I reinforced the hull with a couple of layers of fiberglass cloth. Unfortunately, its impossible to reinforce the Lucas Oil hull without cutting it open. I know people who drilled holes and filled it with expanding foam from the outside, but it ended up messing up the balance of the boat.

Just keep it the fun sporting boat you have now.

[MADRCER]

Damn must of been a hell of a flip lol... I'm not going to try to cut the tub and reinforce it unless it breaks. I was mostly interested in the prop swaps to see which one could pull the most mph on the same set up.

[SD Eracer]

Yup, it sure was

It was loud, everyone that heard it knew it didn't sound well, kinda like a bad belly flop.

I think you will find the X642 the best all-around prop for that boat, even my Pursuit mono seems to like it better than the M445. What's interesting is the temps and lipo pull isn't noticeable more than the mild Grimracer or 445 props.

I forgot to mention that living in San Diego, we pretty much run in salt water, which does allow our boats to go slightly faster than compared to fresh water. So the times I mentioned, you may want to knock a mph or so off for fresh water.

[MADRCER]

Good info on the saltwater. I would have never thought that it would be faster than running in freshwater.

[SD Eracer]

Yup, the salinity increases buoyancy or something like that. It's not a huge difference.

Good info on the saltwater. I would have never thought that it would be faster than running in freshwater.

[martin]

Salt water is denser than fresh, you get more buoyancy & the prop slips less. I run on salt water most of the time & if I run my boat on fresh water with the same set up the boat looks slower but also sounds like its revving higher due to more prop slip.

[CraigP]

The hydro hull skips better on salt, spends more time in the air. We used different props between fresh and salt in GP and Unlimited. We took rake out of the prop on salt to diminish additional prop walk. Also, salt water cools much better! Had to make timing/fuel adjustments. Warmer fresh water is a concern for water cooled FE's...