Brushless Blizzard

[downyours]

I thought you guys and gals would like to see this. This is my Brushless powered Climate Models blizzard. It is powered by a Feigao 6s, CC Barracuda with watercooling, Fuller's Crumbgrabber hardware and octura props. Props depend on how many cells I run. With 6 cells I use a X632, I am going to be squeezing in 8 cells just to see what she can do. I plan on using a x427 or x430. This boat started out with a trinity monster stock (27t) motor in it, but as you all probably know, that didnt turn out so well. So I opted for brushless. So far I am really pleased. She runs in the high 40's on 6 cells, and hopefully will hit high 50's on 8. For some reason I cant upload the photos so I will have to do it at a later time.

[downyours]

Finally got the pics to work...

[downyours]

and the other one... These were on 6 cells and a x632 prop

[Fluid]

With a Kv of over 5900 rpm/volt the 6S is a lot of motor for 8 cells, particularly if they are top quality GP3300s. I'd not run it for over one minute without bringing it in to check for heat, particularly if the pond you run on is small with sharp turns and short straights. With a small prop like the x632 it is a great motor for 6 cells. I don't doubt your speeds, but how did you measure them? High 50s won't happen with the x427 or x430 props.

[downyours]

Well, according to my calculations I have run, I should hit mid 50's on a x427 spinning at a little over 44,000 rpm on 8 cells at about 75 amps. Because of the smaller diameter prop on the x427, it will be able to spin up better than the x632. On 8 cells the x632 would be around 34,000 rpm where as the x427 should be at around 44,000. I run at a lake that is right in front of a civic center and police sub-station. One of the cops stopped one day to check it out and radared it at 48mph on 6 cells.

[Fluid]

Well, according to my calculations I have run, I should hit mid 50's on a x427 spinning at a little over 44,000 rpm on 8 cells at about 75 amps.Calculations can be fun but this probably won't happen. The tiny x427 (with a 30% smaller thrust cone than an x632) will have large slip values. The boat is really too large and heavy for such a tiny prop. This isn't idle thinking, it's based on considerable SAW competition experience; you can't "calculate" everything. You can probably reach the high 50s with an x432, but watch out for high heat if you run for very long. :(


One of the cops stopped one day to check it out and radared it at 48mph on 6 cells. You're likely running ca. 30% slip, which isn't that bad. The SAW record for a 6-cell rigger is over 76 mph, but that setup is only good for a few seconds at full throttle. Your speed is very good for a fast sport boat. :D

[downyours]

Well I appreciate the kind comments. Thank you. I will be trying different prop combinations to see what gives me the best all around performance. I dont race or compete in SAW so I dont need to worry too much about top end. I just want something fast and reliable and so far Im pretty happy. The main reason I calculate speeds and stuff is to keep an eye on how many amps are going through the system. Thanks again.

Also, do you have any suggestions as to any other props I should try? I have Octura's X427, X430, X431, X432, X435 and X632. But thats it. Are there any other brands that I should be looking at? I havent seen many that offer the smaller 1/8 inch shafts. Thanks again.

[Chris LaPanse]

I'd try the props in the 30-32mm range (430, 431, 432, 632). 435 seems like a bit much prop, but as fluid said, 427 is a bit small for this boat.

[crowebar]

Fluid is correct. 8 cells and the 6S will be a tall order. I run the 8S with 8 cells and Y535 and the 6S with 6 cells and x632 on my rigger.
Hope this helps

[BoatDoc]

my nemesis 8S powered blizzard runs pretty good on 1735 and 1732 props. it runs on 6 GP3300's and a Castle ESC. i've only been able to run a few times so far. i'm still working on the set up...i've only made it to the pond 2 times in the last 6 weeks so i haven't been able to try very many props.

[69dart]

try a 1440 prop
you need a lifting prop to get that rear end out of the water
and those pics better not be a pic at full throttle
cause you would be throwin alot more water around at 48 mph
the rear end really looks like its sludgin

[crowebar]

I think a 1440 is going to release the magic smoke from your ESC. If you want to try a lifting prop on the 6S try the 1732, but be careful, that's a lot of prop for that little motor too.

My guess is your setup is off. I race a guy in my club who runs a blizzard with a x632 and he runs right with me. Not sure what kind of speed we're at but I'll bet were at least in the mid 40's.

[BoatDoc]

i agree, a 1440 is too much prop. a 1732 would be much better.

[Fluid]

try a 1440 prop you need a lifting prop to get that rear end out of the water The 1700 series props are lifting props, and like the others have said, a 1440 will likely cause excessive heat and damage with that motor if run for very long - it is too big.

However, you don't need a lifting prop at all, as long as you can angle the prop shaft down a few degrees at the aft end. This will supply all the lift needed and allows you to adjust the amount. The problem with the 1700 props is they may have too much blade area for that 6S motor. The x632 has less pitch and blade area thn a 1732 does, and the x432 is even better from a safety standpoint. We won't know until you run a few times, but be sure not to run more than one minute (use a stopwatch!) at a time to check for heat.... :eek:

[BoatDoc]

i tested the x431, x432 and a modified x534 all with very good results. they all had excellent accelleration and nice top end. the lifting props didn't accellerate at all. the x props also felt better in the turns. i'd say to give those three a shot, you'll probably like them.

[BoatDoc]

i know this thread has been on the back burner for a while...but i have another suggestion. i finally got around to modifying an X632. i took off a little tongue, gave it a slight back cut and a bar cut. it's running faster than my bar cut 432 and coming back in about 3 - 4 degrees cooler. the boat is on plane instantly and it MOVES OUT!!! i'm running a pretty flat prop angle too. i've also cut the turn fin down a bunch...it slides in the turns just a little but is still stable and predictable.

[performula]

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