What would it take to build a 100MPH Cat

[Chilli]

Props aren't a problem for him, he is a master RC prop maker.

I've got one hanging off the transom of my gas boat

[Doug Smock]

I've got one hanging off the transom of my gas boat

Mmm me two, Mono and Cat.

[ls1fst98]

man id love to see this happen! 100 mph in an rc cat would be insane. would a gyro help with stability at those speeds or are they kind of a waste in a boat?

[Flying Scotsman]

Chris, are you GPS racing or going for a record? The problem isn't power, we have plenty of power to push a cat to well over 100 mph - the Germans do it all the time. The problem is boat design. Virtually all North American cats are designed for oval racing and handle great - but they have way too much lift and will not stay on the water at 100 mph for 330 feet. I've tried air dams and tunnel tabs which can help, but the solution is not band-aids but better design.

The German cats are modeled after full scale racing catamarans and their tunnel design creates far less lift. Too, their sponson design helps to keep them stable at high speed. Most of them handle terribly.

I designed a little lightweight 12-cell NiMH wood-on-foam cat in 2004 and set the NAMBA P and Q SAW records for offshore - those records stood for years after we went to LiPos. That boat was fast because of its design, at the time it was the fastest non-rigger FE boat period. The power was anemic compared to what we have today, but the Q Offshore record was finally broken only last year.

Your Drag Cat may reach 100, but you will blow off and damage it before you get two consecutive passes. A crash at 100 is far more brutal than one at 80. If you are serious about a 100 mph cat, get one with a narrow tunnel having a gradual entry angle. Run 10S2P with a Neu 2215/1.5Y or 2220/1Y, you will have plenty of power.

Twin motors have the advantage of no prop walk - assuming you can find matching left and right handed props. Otherwise a single is just as good with the motors we have today, IMO anyway.



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One of my favourite topics, Ok you reach 100 mph, what is next 125 mph, lads these are missiles in inexperieced hands who copy the original design....my 2 cents.

Douggie

[dasboata]

One of my favourite topics, Ok you reach 100 mph, what is next 125 mph, lads these are missiles in inexperieced hands who copy the original design....my 2 cents.

Douggie

Get your facts Right you better reread the posts I do know something about going fast I competed in oval and SAW events for 10-12 years setting 9 NAMBA SAW records and about the boat you better re read the posts have a great day Chris

[MarkF]

Hi Chris, dont let some of these nuckleheads get to you. I agree on the Neu 2220 1y motor and 10s getting you over 100 mph. Also a Castle HV 240 speed controller. You did some props for me and I got a speed freek sport hydro over 105 mph with a prather 260 you did up for me but I don't want to recomend the motor I used. Its a little on the hot side but I think the motor I recommended above will work great for you. I would start with a prop in the 52 to 55mm range with 4" of pitch as a start and work up from there.

Mark

[dasboata]

I appreciate all the info you Guys are giving me here!!!! I have dealt with alot of you guys in the past,,, !!! and I really appreciate the information I am recieving here and I do feel the LOVE all though I might not answer each one individually I Thank you all !!!

[Jeff Wohlt]

As Fluid said...check out some of the German sites and videos. They have the set ups listed and everything. It is common for them to be in the 100 mph range with cats... Nothing that special except many use the lehner motors and HV ESCs and lipos. Great props get you everywhere.

[Fluid]

The boat below has made passes over 125 mph on 10S; note it is long (135cm) and very narrow so as not to pack excess air. Nice video, the hull is rock solid at 127 mph!

http://www.rbc-allgaeu.de/storage/vids/Norbert.wmv

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[Jeff Wohlt]

Now that is ART! Love the NON stinger set up. This really helps playing with big props.

[Flying Scotsman]

Get your facts Right you better reread the posts I do know something about going fast I competed in oval and SAW events for 10-12 years setting 9 NAMBA SAW records and about the boat you better re read the posts have a great day Chris

I know who you are and you are very experieced, my point was that a newbie would copy your setup and ?

I look forward to reading your posts on this project.

Douggie

[Jeff Wohlt]

Nice response, Douggie. Very true.

[dasboata]

I know who you are and you are very experieced, my point was that a newbie would copy your setup and ?

I look forward to reading your posts on this project.

Douggie

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Ok glad you straightened that out I hope I get this project going I have a lot to learn about electrics,,, and will try to get my mean machine going,, and learn from that,,,, then take on the drag cat project thanks chris

[dasboata]

The boat below has made passes over 125 mph on 10S; note it is long (135cm) and very narrow so as not to pack excess air. Nice video, the hull is rock solid at 127 mph!

http://www.rbc-allgaeu.de/storage/vids/Norbert.wmv

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Yes I have seen that vid very impressive thanks Chris

[RaceMechaniX]

Chris,

OSE has a very useful tool for calculating speed with FE's.

http://www.offshoreelectrics.com/conversion.htm

Scroll down the page till you see the Speed Estimate by Use of Voltage & Constant "Kv"

Then plug in the numbers are away you go. You find you probably need something in the 900 to 1200kv range with appropriate slip to hit the 100 mph mark.

You are also going to have one hell of a time trying to seal up the Dragcat, but I know you like challenges.

Tyler