prop for a 31" cat..?

[brushless4life]

Nothing like another prop thread..


I happen to have some goodies lying around from abandonded projects. A feigao 6xl (2871kv) and a few different esc's. I have a water jacket for the motor as well.

I came across a thundercat 31 (nitro) that i want to convert, any suggestions on what would be a good prop(3/16)?
Stock prop (1.6 x 2.5) is comparable to a prather 215 i believe, but no idea how that runs or if it would be a good place to start. I know some trial and error is going to be needed but if i can avoid burning things up to start it would be great. Not looking to make this thing break records, just want something pretty quick and reliable. More then likely going to run on a 4s 5000 mah 40c battery maybe 2 in parallel depending on what kind of runtime i get out of it. I could move up to 6s if i had to run a little more prop, but really dont plan on going to anything that would require me to buy esc's to run like 10s setup.
So any suggestions on what could make this possible on 4s would be great.
Thanks in advance.

[FE Wannabe]

I am by no means an expert, but I do know that a 6XL on 4S is a recipe for disaster. You shouldn't run a Feigao higher than 40,000 RPM and expect it to last. The 6XL is a 3S motor. In my opinion your hull is too big for a 6XL anyway.
I am just trying to help keep you from:flashfire:
I too was thinking of running a 6XL in my 32" mono on 3S2P (2ea 3S packs in parallel) but was told by FE boaters much wiser than I, that 6XLs have reliablity issues when pushed (high amp draw).

Also, in general, the higher the RPM the smaller the prop, not larger (6S vs 4S).

Here (http://forums.offshoreelectrics.com/showthread.php?t=5727&highlight=Thundercat) is a great thread on someone else that converted their Thundercat to brushless. This should help you get started.
Remember anytime you start off with a new setup, check your temps often, like every minute, to make sure everything is OK. Heat will tell you if you are pushing anything too hard.

Brad

[m4a1usr]

If you are sticking with 4S you might consider a 580 7L or 8L motor. No way you are going to run 6xl in that hull with out smokin parts. The TC31 is a good hull to convert to FE but you need to research what others have used to be successful. I use a Neu 1521 in mine and its more then enough motor for decent speeds but price can be an issue. Mine runs fine on a Prather 225. Temps cool and speeds alright. Not the fastest but heck it dont come back hot or smoke and sink because of poor planning.

John

[calcagno45]

I would look for a 1515/1.5Y on 5s with a M545. I ran that in my converted TC31 and it was absolutely great! Cool, strong and fast!

[brushless4life]

thanks for the replys.. the 580L is sounding like a good option.