Fast hydro

[brad nichols]

Can a single electric be as fast as a twin because of the extra weight? What brand of motors and ESC are recommended to achieve the 100 + mph mark? I am asking for a boat build for someone. He wants to go with a Road Runner hydro for the build. Any help with info or ideas is appreciated.Thanks

Brad

 

[Steven Bryant]

Hi Brad my experience is with singles only, but from what I've seen there is not a huge amount of difference. over the last couple of years I've converted several nitro riggers over to electric with varying success. My most successful build was converting an Eagle SG to a 6s setup using a Lehner motor and MGM esc, this boat runs in the 70's in heat racing trim.

To be honest i would not convert another nitro hull as they don't lend themselves to FE and need lots of mods.

I think your friend would be better off buying an FE rigger or scratch building one.

Good luck

 

[ALLAN YUEN]

Can a single electric be as fast as a twin because of the extra weight? What brand of motors and ESC are recommended to achieve the 100 + mph mark? I am asking for a boat build for someone. He wants to go with a Road Runner hydro for the build. Any help with info or ideas is appreciated.Thanks

Brad

Doubt who is he??

 

[RaceMechaniX]

Brad,

In ideal water a well configured FE single will likely be faster than a twin. In race water, the extra heft of a twin FE may be a bigger advantage to running consistently fast. That said if you are not FE savvy, building a twin FE for 100mph in heat racing trim is going to be a challenge.

Hate to be the downer, but what you are asking for requires cubic dollars and hardware that is difficult to find. A 70-80mph twin is much more doable.

Tyler

 

[lohring]

Didn't Brian Buaas go 134 mph with a 4S hydro? It didn't take money, but it did take Brian's skill. Two propellers in the water will always have more drag than one. So far one propeller can be big enough to absorb all the power from our power plants.

Lohring Miller

 

[RaceMechaniX]

Brad, is this a SAW rigger or a heat racing rigger? I assumed since you mentioned it was a Roadrunner we were talking about an oval boat.

 

[gil sonsino]

Agreed with comments but it's possible to have a 100 mph budget twin rigger...here is one with top speed of 106 (heat set up): http://grsboats.com.br/novosite/?portfolio=grx-twin-fe-rigger

Gill

 

[ClintonSalter]

I have a crap box TOBSD cat with two 3674 3600kv and 125a cheap esc and two descent 6s batteries. Will run 76mph all day with 38mm props. Swinging some custom 46mm props and has been just under 100 mph. Setup is key. Easy 80 and less than $600 in the whole package

 

[brad nichols]

I was asked to build a boat for a guy in Austrailia. I don't know enough about electrics and was looking for info on motors, ESC's, batteries, etc. for a build. All info is appreciated.

Thanks

Brad

 

[RaceMechaniX]

Brad, lets start with what the boat will be used for: Play boating, SAW's, 2-lap or heat racing?

We can make some recommendations from there.

Tyler

 

[brad nichols]

Heat race boat. Gil sent some pic's of his and it looks very impressive!! I am a newbee to electrics and don't understand the way mtors are rated? The numbers and KV ? Any info would be a great help for myself and others I am sure.

Brad

 

[Steven Bryant]

Hi Brad what size roadrunner, 67, 90, twin etc?

Steve

 

[brad nichols]

After a good talk with Ralph, there was not enough information about the components that it would be better not to build something at this time and it would be better that Ralph and him would have to talk about it.

Brad

 

[RaceMechaniX]

Wise decision. A 100mph twin electric heat racing hydro is harder than a 140mph SAW rigger.

 

[brad nichols]

But I am still interested in information! On Niklas's Phydro and P open what is the diferance ? I see the open is longer and the motor dis. can be larger and longer? so waht's the difference? What would you change between the two? Motor, ESC and batteries and what would you run on the P and what would you run on the P Open?

Thanks

Brad

 

[BobHorowitz]

Boy, I'm really interested in hearing some answers to Brad's questions as he is building one of Niklas' P-Limited boats for me. I arbitrarily picked components based on my newbie knowledge, basically the UL1 setup and what Niklas recommends on the drawings. I'm pretty sure what I picked would not be legal for a P-Limited boat. Probably not even close to competitive for a P-Open. So, I'm just a sponge for more knowledge. I wonder if anyone could point me to the rules for P-limited and P-open outriggers.

Regards to all,

Bob

 

[lohring]

The NAMBA rules are in the rule book under resources on the NAMBA web site. Essentially the UL-1 motor can be used with up to 10,000 mah of battery and any ESC. I run 5000 mah packs with a Turnigy Marine 120 ESC and 5.5 or 6 mm bullet connectors. That;s a pretty bullet proof power plant with the motor as the "fuse". Brian Buaas' Raptor or the JAE riggers are both very competitive in our area. Offshore Electrics and the Hobby King American warehouses are a good source for most electric products. Be sure you know what you are buying from Hobby King. Their products vary from great to bad.

Lohring Miller

 

[BobHorowitz]

Lohring,

Thanks for the response. I took a quick look at the NAMBA rules for P-Limited boats. Maybe I missed it, but I didn't see anything about P-Limited outriggers. Did I miss it?

 

[Christian Lucas]

Hi ,

have a look at this small outrigger hydro from Patrick alias Shark , http://www.rc-raceboats.de/forum/showthread.php?31104-Mini-Dragster-Rigger-(Twin-Antrieb). This is a only 45 cm long rigger that is fired with a twin Scorpion 2216/12 outrunnermotor setup running from 2S up to 4S . This is a real dragboot that reach up to 106 mph . In answer #28 is a vid of a 100 mph run. Very fast accelerating !Jörg calculate about 5,4 g rate .Patrick runs only 4S 1800 mAh lipos ,preheatet. This little screamer show us that power is not all . Patrick wants to show that the small torque outrunner can be used if the strong torque is counter by the counterrunning propeller to have low propwalk effect. Also with counter running propellers you can use a much smaller ruder to hold the boat straight that has much less drag and it can have a simetrical,profile no need of the wedge ruderprofil type that has higher drag.

 

[lohring]

At the start of the electric rules it says they are a supplement to the general NAMBA rules. That means that the general hull types, mono and hydro, are described elsewhere. All the specialty hull types in the electric section are special cases of monos or hydros. The motor, battery, and hull length restrictions for electric power need to be as described in the electric section.

Lohring Miller