Spartan 4S prop recommendations

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!

Welcome to the forum. You need to change the rubber on the motor to an aluminum cooling can. An Octura x442 will work good with your setup and adding the inner trim tabs will make a difference. This has been my experience with the Spartan.

I only ever ran a Spartan on 6S for a handful of outings, but found that minimal trim-tab (parallel to the hull bottom) and batteries all the way back was how I ran most. Most of my tunin was done with strut angle. I agree, a 42mm prop will be a good start on 4S.

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Originally Posted by Revolt Flash

Welcome to the forum. You need to change the rubber on the motor to an aluminum cooling can. An Octura x442 will work good with your setup and adding the inner trim tabs will make a difference. This has been my experience with the Spartan.

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Appreciate the input Revolt Flash!

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Originally Posted by fweasel

I only ever ran a Spartan on 6S for a handful of outings, but found that minimal trim-tab (parallel to the hull bottom) and batteries all the way back was how I ran most. Most of my tunin was done with strut angle. I agree, a 42mm prop will be a good start on 4S.

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Pretty typical of what I am reading online fweasel. Most folks are 6s. I am gonna stay 4s for a good while. Me and my boy are new to boats. But he’s been driving cars since 4 and racing since 5. So he gets why we aren’t doing 6s yet when he sees some of the videos!


The heat sink is most definitely on my list. Probably get it whenever I decide on a prop. Dual intake was a higher priority for me as a first add while I run with the stock prop.

I know the copper beryllium blade will have far less deflection and should help on the upper end a bit. I wonder if the lack of deflection helps or hurts cavitation at throttle hit?

Right now I am seeing that stinger angles and battery placement that gives good top end results in pretty sluggish holeshot. Kinda wondering if a little more diameter or a 3 blade would offer more low end bite and reduce prop slip at speed. Since I will be staying 4s, there is some additional room in the electronics for a touch more amp load than if I was going 6s.

I pretty sure you will find that the 3 blade will make it handle better rather then give it more speed.

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Originally Posted by OneGoodie

Appreciate the input Revolt Flash!



Pretty typical of what I am reading online fweasel. Most folks are 6s. I am gonna stay 4s for a good while. Me and my boy are new to boats. But he’s been driving cars since 4 and racing since 5. So he gets why we aren’t doing 6s yet when he sees some of the videos!


The heat sink is most definitely on my list. Probably get it whenever I decide on a prop. Dual intake was a higher priority for me as a first add while I run with the stock prop.

I know the copper beryllium blade will have far less deflection and should help on the upper end a bit. I wonder if the lack of deflection helps or hurts cavitation at throttle hit?

Right now I am seeing that stinger angles and battery placement that gives good top end results in pretty sluggish holeshot. Kinda wondering if a little more diameter or a 3 blade would offer more low end bite YESand reduce prop slip at speed.NO Since I will be staying 4s, there is some additional room in the electronics for a touch more amp load than if I was going 6s.

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my experience with running 3 blade props is it will come out of the hole better, handle better, but not a change in top speed...

Quote:

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Originally Posted by Revolt Flash

I pretty sure you will find that the 3 blade will make it handle better rather then give it more speed.

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Thank Revolt Flash. That aligns with some of my full size boat experience. Went from 3 blade to 4, added some cup and pitch. Gave the boat a tad more lift and top end, but didn't kill the great holeshot we already had. Assume these small boats should behave similar???

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Originally Posted by bogieboy

my experience with running 3 blade props is it will come out of the hole better, handle better, but not a change in top speed...

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We definitely need an improvement in holeshot. If I try to set the stinger at 0 degrees it flat sucks right now (takes 3/4 of large/small lake), humms once its up though. Have to be at 1 degree or so, but 2 really comes out better. Found the best overall to be between 1 and 2 down and the batteries about 1 to 1-1/2 inch from the back. Running SMC 7200s that I use in my pig 4x4 Short Course racer. Hardcase, so some weight penalty there...but I already have 8 packs!!!! Trying to find a decent holeshot but not run wet on top end.

Well, the boat has already shown the limitation of a couple “good” and couple “mediocre” car packs! 😂 So I now have 4 packs that are good for the boat. 😳

Made a few runs today, we had light but steady winds from the south so the little lake I am running at had some chop on it.

Started out with tabs at inner position only and near parallel with hull, adjusters and second set on the way for delivery next week. The batteries were set dead middle of trays and the stinger at level to 1/2 degree down. Lots of bow hop and some torque roll as she bobbed up on down on the chop. Ended up moving the packs back about 1” from the back and setting the stinger ~2 degrees down. Had far less bow hop and either a bit of torque roll or chine walk when it really wound out...I wasn’t sure.

Can’t wait to get the new cooling and trim fab gear on it. Then I’ll start tinkering with props.

Thank you for the input!!!