gas motor electric equivalent

[urbs00007]

https://www.youtube.com/watch?v=no89QauLH9o&t=21s what reasonably priced electric set-up will give me this outcome? thanks in advance.

[Bande1]

you can hit 90+mph in an outrigger with a 4082 motor.

https://youtu.be/TDR0PCUzQlI
https://youtu.be/fAuUyln8KgI

a cheap setup would be a zippkits JAE33fe, a rocket RC 4092 with an OSE 150 esc. spend money on batteries and get SMC 6s packs.

[urbs00007]

you can hit 90+mph in an outrigger with a 4082 motor.

https://youtu.be/TDR0PCUzQlI
https://youtu.be/fAuUyln8KgI

a cheap setup would be a zippkits JAE33fe, a rocket RC 4092 with an OSE 150 esc. spend money on batteries and get SMC 6s packs.

thanks for response. my goal is to take the gas motor out of the boat in the video and replace with electric. sorry for not making that clear. thanks

[lohring]

I've dynoed a lot of Zenoahs and one, an M&D modified Zenoah set the first over 100 mph record. In 2004 we set the first over 100 mph gasoline powered boat record with a Quickdraw. It later set a record of 109+ that stood for years. IC engines are rpm limited. That means getting props with enough pitch and over rev power is the secret. A modified Zenoah doesn't develop significant power over 20,000 rpm. The Quickdraw can run up to 25,000 rpm with some power left. Both engines have between 5 and 6 hp at these rpms. That means you need something like 4,000 to 4,500 watts of electric power.

I would try to do this with a 6S or 8S setup. With 6S it would take around 180 amps, and with 8S it would take about 140 amps. At 10S it would take a little over 100 amps, but the best affordable ESCs only handle 8S. At 35,000 rpm you need at least 94 mm pitch to run 100 mph. To get that pitch you need to run 20 or 21 series ABC props. These are 50 and 53 mm diameter. I bet you might need to cut down the diameter to keep the current reasonable. The only similar data I have shows 100 amps minimum and 150 amps maximum at 23,000 rpm with a 57 mm diameter prop on an 1/8 scale boat. We ran an 8S setup and set a 2 lap record. Since the power to a propeller varies as the cube of the rpm that prop would draw over 500 amps maximum at 35,000 rpm.

Lohring Miller

[Peter A]

thanks for response. my goal is to take the gas motor out of the boat in the video and replace with electric. sorry for not making that clear. thanks

One of the guys in our club blew the gas motor in his slingshot rigger. He decided to convert it to electric. It is now running faster than when it was gas, 135 kph in oval form on gps.
Set up is, TP 5670 650 kv, ztw 300 G2, 12s 5000 mah ( 2 x 6s packs), prop is a detongued X470. It does a heat race without problems and comes back with 'gas in the tank'. It is effectively running around the 5hp+ mark.
You have to bear in mind that the guys running at 90 mph have spent years perfecting their art, and you have to learn to drive at those speeds, especially if you are oval racing.

[lohring]

The higher voltage is always better. Current is what melts things. A rough calculation with that setup shows about 90 mph. What was the current draw on that prop?

Lohring Miller

[Peter A]

The higher voltage is always better. Current is what melts things. A rough calculation with that setup shows about 90 mph. What was the current draw on that prop?

Lohring Miller

No data logging but he comes back at over 30% left, so roughly averaging around 90A on 5000 mah packs.

[lohring]

That seems low compared to the only data I have. The speed calculation checks out at around 20% slip. Your input power is around 4,300 watts or 5.7 hp. That's a little lower than modified 26 cc gas engines should be putting out in heat race trim. The best 26 cc Zenoahs dyno at 6.5 hp or close to 5,000 watts. They can only hold this to a little over 18,000 rpm. The ability to turn 30,000 rpm allows a lot more reasonable prop pitch. The best gas riggers are running close to 150 mm pitch while your friend's boat runs 98 mm. The pitch ratio pretty much matches the rpm ratio of 19,000 to 30,000.

Lohring Miller