Vee Hull Prop Recommendations

[OneGoodie]

I put this up in the Traxxas RTR section, but I noticed it didn't have a ton of traffic after I posted.

Ok folks, I picked up a great condition used Spartan for my 11 year old for Christmas. I want him to spend his time having fun instead of tweaking for speed, so we are staying 4S. In addition, I have tons of 2S and 4S packs for racing cars, but zero 3S packs. I have done some looking for recommendations on prop selection for 4S, but have struggled to find much. Most discussions are around attempting to attain speed on 6S.

I am wondering about slightly larger diameter or 3 blade prop instead of 2? Right now it tends to be pretty slow out of the hole with ok speeds. Remember, this is for a 4S system. I don't plan to drop $$$ on a bunch of 3s packs just for the boat when I have tons of 2s packs!

Props I have seen mentioned explicitly for 4S is Y547 or M445, also saw X442 as near identical replacement to stock dimensions.

Boat info:
Stock TRX ESC and motor
Stock motor cooling jacket
Dual pickup and outlet on order, will be here this week.
TRX adjustable trim tabs on order, will be here next week.
Will be running inner and outer tabs
Stock turning fins
Stock stinger
Currently on stock prop

Testing this weekend seemed to show that outer trim tabs have minimal affect on boat attitude when its up on pad. Battery location and stinger angle had far more effect. Ran packs from full forward to full rear and multiple stinger angles at each position. Found a pretty wide operating range that was suitable, just some were a touch slow out of the hole. Boat handled well and only had minimal chine walk on the most extreme range of bow lift.

Any experienced input or firsthand testing knowledge would be much appreciated!

[srislash]

I have not had a Spartan but have seen enough of them on 5-6s. Trying to remember if my pal did start on 4s ?? I do recall him running a Prather prop tho. I believe the Spartan runs a Castle 1520 in it but I’m not positive on KV, and my search was inconclusive on Traxxas site. But a Castle 1520 is 1600kv and I’d say a 47mm prop should be good. If that gets the boat rocking back and forth too much at speed then it may mean the prop centreline is too low for that diameter of prop. Then you can go down in size and up in pitch.

Shawn

[OneGoodie]

I have not had a Spartan but have seen enough of them on 5-6s. Trying to remember if my pal did start on 4s ?? I do recall him running a Prather prop tho. I believe the Spartan runs a Castle 1520 in it but I’m not positive on KV, and my search was inconclusive on Traxxas site. But a Castle 1520 is 1600kv and I’d say a 47mm prop should be good. If that gets the boat rocking back and forth too much at speed then it may mean the prop centreline is too low for that diameter of prop. Then you can go down in size and up in pitch.

Shawn

Thanks!

The stock motor is an 1800kV motor (Castle 1420).

I was thinking a little more diameter may help holeshot, reduce slip, and not over tax the system since I am running 4S.

[srislash]

Oh yeah that’s right, 36mm dia motor. You would be correct with the larger prop or a 3 blade. But a 3blade will hurt runtimee

[HTVboats]

I would stay away from props over 1.4 pitch ratio and 45mm diameter as they will overload and overheat a small motor. Too much diameter will just cut your run time. You might be surprised what a 440/3 blade will do. Plenty of blade area to push a larger hull and should extend run time.
Mic

[Speed3]

The octura m545 is another option for 4s, will give a significant increase in speed over the stock prop. And accelerate a lot faster too. Runtime will be shorter though.

[OneGoodie]

The octura m545 is another option for 4s, will give a significant increase in speed over the stock prop. And accelerate a lot faster too. Runtime will be shorter though.

Than you Speed3.



I would stay away from props over 1.4 pitch ratio and 45mm diameter as they will overload and overheat a small motor. Too much diameter will just cut your run time. You might be surprised what a 440/3 blade will do. Plenty of blade area to push a larger hull and should extend run time.
Mic

Thank you HTVboats!


I ordered a x440/3 and x445/2 on here to do some testing on. Didn’t have an x442/3 in stock when I ordered and didn’t want a x442/2. I stayed with the X series over the M based on some comments about detounged props being a little slower out of the hole. Considered a Y547, as it is the highest speed report on 4s I have found online. But in the end I didn’t want to go to a 47mm from 42mm.

Dual pickup kit will be here tomorrow. New motor jacket and tubing early next week. I have access to tons of old nitro tubing, but the ID is too small. 2 props, second stainless trim tabs, and trim tab adjusters all coming in early next week as well. So hopefully I’ll have some feedback on it by the end of next week, weather permitting!

Thank you for all of the helpful input!

[OneGoodie]

Well, ran the boat with a new stock plastic prop today. Wow, different animal with a prop with fresh edges on it!!!

Running dual cooling pickup, inner and outer trim tabs (no adjusters yet), new stock plastic blade, stock electrics, 4S


https://youtu.be/_z8XvCleRJE

[OneGoodie]

Slow mo shot


https://youtu.be/DlRmGOQYtug

[OneGoodie]

Last 2 videos then I will be done with this thread. Thank you for the prop input guys. Ran 2 props today, both CNC aluminum props from OSE. All I can say is wow. One was the 3 blade 40mm the other was a 2 blade 45mm. The 45mm was just a touch slower as it bogged down the motor more. Ended up puffing an SMC 7200 100C pack due to excess current draw from the 45mm. The three blade really sounded awesome and made some good speed and decent run times. May try a 42mm 2 blade if they are in stock.

Here’s the 3 blade 40mm video.
https://youtu.be/JhvoExTlySo

[OneGoodie]

And the 2 blade 45mm video. Batteries full rear and stinger at plus 1-1/2 or so.


https://youtu.be/WoVYXE8bmYI