What would it take to build a 100MPH Cat

[ManuelW]

Hello Chris,

just a few recommendations from my point of view: For going 100mph I wouldn't rely on common FE speed calculators. They might be quite accurate for lower speeds but for 100mph I think the difference is just way to big.

And for size/width: It all depends on the hull, you can also run very fast with short and quite wide hull. This means aero- as well as hydrodynamic as well as the right setup and correct CG and trimming. You can even achieve stable 100+mph at SAW with a 35" cat hull (thats shorter than a Genesis)

But I have to say that I have as far as I remember never seen a single engine cat running close to 100mph at an SAW event. It might be possible but very very difficult. Therefore I'd try it with two engines.

For Norberts HPR 135: I have seen it running at Ertingen and its an amazing machine but be aware that they have really plenty of knowledge for going so fast.

I don't know your hull and if its capable of these speeds. As said blow-overs at these speeds are just horror. So lets say your hull is strong enough and capable to handle these speeds, you might want to go for a twin-Scorpion Setup with 2x 12S Lipo and Octura X457 props.

Best regards,
Manuel

[RaceMechaniX]

I would agree that twin motors are going to make achieving the target easier, unless you are willing to put a large motor in there. Counter rotating twins are going to make the attitude much more manageable than a single large diameter prop. I've seen the 80+ mph dragcats first hand and without a doubt are super prop sensitive. Swinging a big prop with more RPM than a gas motor cranks out is going to make that short hull do crazy things.

Assuming you are going for an IMPBA or NAMBA record you will need to stick with 10S or below.

The Scorpions will be able to swing the big props with enough pitch, but they are not going to spin crazy rpm. All of the 100+ mph cats I have come across online are running inrunner style motors, i.e. Neu, Lehner, Plett, etc. And most are spinning in the range of 40K+ RPM.

Tyler

[graill]

Hi Chris, have a ton of your props (if your the dasboata Chris) Nice to see you on the forums Now.

Nice comeback Douggie.

[dasboata]

Hi Chris, have a ton of your props (if your the dasboata Chris) Nice to see you on the forums Now.

Nice comeback Douggie.

That's me thanks for the welcome

[ManuelW]

@ RaceMechaniX: Well I'm quite sure it does work with Scorpions as I have a twin-powered cat probably a bit bigger/heavier than the dragcat running on a Scorpion Setup and it does run >100mph.

Best regards,
Manuel

[RaceMechaniX]

Manuel,

I stand corrected. Are you willing to detail your set-up? Which Scorpions, controllers and roughly what size/pitch props.

Tyler

[ManuelW]

Hello Tyler,

no problem: 2x Scorpion 4035/800, 2x YGE 160HV, 2x 12S 5000 40C, 2x Octura X457 --> 100mph. But I think it needs some knowledge in FE setups, wouldn't recommend it to a Rookie.

Best regards,
Manuel

[RaceMechaniX]

Thanks Manuel,

I was uncertain as to what frame size motor you were spinning that high. An outrunner spinning 35k is moving. When I run those numbers using a X457 prop, you have to have very low slip in the single digits, full packs and mid ninties efficiency to hit 100mph. This assumes you have no extra cup either.

Tyler

[ManuelW]

Yes, as said I think it needs a little bit knowledge to run it successfully. And for all boats >100mph I think its necessary to run them as efficient as possible. The Props have a slight cup.

Lenght: ~55"
Weight: ~21lbs

Best regards,
Manuel

Here some pictures (first picture compares it with my HPR06):

[FE Wannabe]

Chris,

If you have DEEP pockets you could always buy a RTR 100mph Cat from BK Electronics.

You may need to use an online translator to read the details, unless you speak German. Check out the Bandit M Pro or the Cool Runnings twin drive cats.

http://www.bk-electronics.com/html/elektro2.html

All you need to provide is a transmitter, some props and a Swiss Bank account number and supposedly you're doing 100mph!

I would love to see BK's disclaimer on these RTR boats.
Something along the lines of "Please do not kill yourself or anyone else with this boat".
I couldn't imagine someone with a lot of money and little to no FE experience buying one of these and turning it loose, especially on a crowded lake!

[dasboata]

who sells the Scorpions and the YGE ESC needed

[HOTWATER]

who sells the Scorpions and the YGE ESC needed

You can get Scorpion motors here ---. http://southriverrcboats.com/shop/ar...SC-4035-630%26

[ManuelW]

@ Chris:
The link to the motors was already posted.

Here the controllers I used:

http://www.yge.de/artikel.php?search=yge160hvnavy

But be aware, just copying the setup might not be enough. If further questions arrive I'll try to help.

Best regards,
Manuel

[dasboata]

I am going to go twins in the drag cat !! Well I just purchased 2 2028 CC that is what I will be using looking for suggestions on the speed controls I might get the swordfish from Steve what do you think ? thanks chris

[K.R.Joye]

Chris the Swordfish 240 ESCs should be fine probably the best mid-range($) controllers on the market. I really admire your decision to go twins. The easy way out would have been to run one 2215.
You will need 8-10S Lipo(depends on props) to get max power out of that setup. Get the highest (name brand) C rated cells(45C+) for best results(T-Power, Flight Power, Hyperion etc).That Hull should do the trick fill it with foam to keep the testing damage to a min! Good luck buddy, can't wait to see the vid!