Help - i really need some advise- conquest

[GRAEME LOUW]

I am trying to get electric boating going in South Africa as there are a lot of gassers here and I am the first person to start playing with proper electrics. I have a Aeromarine Conquest that had a Leopard 5698 - 910 kv motor with a 240 HV ESC running with a 452 prop and 10 cells and was getting 100 km/h from her. I wanted more speed so a bought 2 x TP Power 4092 - 1600 kv (4200 watts max watts ) running with 2 x Turgegy 180 ESCs and 6 cells Nanotech 45-90 batteries 5000 mah. Drive was through two stinger drives that I mounted right at the bottom in the middle of each sponson. Max speed is 77 km/h. So I removed the stingers and remounted them so that half the shaft was on the same plan as the bottom of each sponson. Speed no change at all. What am I doing wrong,as I live in South Africa and we cant get anything here so I have spent a fortune in boat motors etc
The two motors dont seem to rev as they should but are my stingers to blame. I cant believe that from a single set-up with less watts to a twin setup with more watts the speed can be so low
Please can somebody give me some advise
Thanking you
Graeme

[Fluid]

Twin motors is not the best way to get more speed IME, although twins can be very fast. Your single setup had an excessive Kv - members of my club get into the high-60s/low-70s with 10S boats running higher-quality motors with 750-800 Kv values and x462 to x465 props. Your budget 910 Kv motor could not swing a large enough prop to go much faster in that large hull. That said, your single setup seemed to be running about where it should given your choice of components.

I cannot say that about your twin setup since you have not told us about your propellers. Typically the stingers are mounted with the bottom of the stingers on the same plane as the sponsons bottoms, not hanging below the sponsons. I suspect that your prop pitch is too small to get the speeds you want. Too, your cat's attitude may not be optimum for top speeds with the twins. A photo of the transom would be helpful.


.

[siberianhusky]

Smaller motors and smaller props. A given prop at 30 000 rpm is only going to move so much water so fast, thats your limiting factor.
If a prop is capable of pushing a boat at 50 mph at a certain rpm a pair of them will still only be capable of 50 mph at the same rpm. You suddenly aren't moving water through the prop at 100mph.
This is a very basic explanation , it's ignoring quite a few things but you should get the general idea.

[GRAEME LOUW]

Hi Guys
Thank you for the advise. I have tried x445 all the way to 450s with thec same results. Please can you let me know what motor do recommend for a single setup for a top speed of about 120-130 km/h. I will start all over again. I am from South Africa so everything I buy from the world must be x 8-5 USD to 13.5 fOR POUNDS and I have already waisted a lot on blown motors and ESCs. What do you think of Leopard ,TP Power and I see you can buy a motor that is adversised as 12000 watts for $100 with various KV ratings.
When I ran the Leopard 5698 - 910 kv on 10 cells I got 100 km/h but blew motor and the ESC 240 AMP and only when I contacted Leopard direct did they tell me max volts was 9 cells.
I was told to use 5- 10 cells by Fine Design and have had no response from them after buying the products from them.
What can you recommend for a reliable setup thats not too expensive for a 120-130 km Conquest. Prop , ESC

[drwayne]

Hi
I saw a comparison run between leopard and TP in same boat.... the leopard roared ... .
Leopard stated 9S to 910Kv as a limit to total rpm of around 35krpm.
That being said, I successfully run SF240HV on 12S to their 5692/730 ( 36500rpm ) to X665... your speeds were met. ( but you need extra caps between batts, esc and motor... )

This OSE website has a treasure trove store that delivers good products ( not a free advert... just fact )
Alternatively eBay can find 56xx leopards around $150USD from asia ( hobbyhot2010 just for eg ) .. but aftersales is a joke.

The TP motors at 12KW .. yes, Ive seen those .. find a marine hull large enough for the truckload of batteries you'd need, and ask again !

Fine Design have applauders and detractors. The great divide between the 2 groups is legendary.
Id check on this forum for previous discussions on FineDesign, for your own appraisal.

here is my Aeromarine cat twin

cheers
Wayne

[siberianhusky]

Speed costs!
I have no experience with high voltage setups, but I do know that guys who are going fast with big setups are typically running Neu, Lehner and some Castle motors.
Do a search for similar sized setups and check out what guys who are running the speeds you want to run are using.
Sounds like you're having the typical Fine issues! LOL I got in touch with H&M in Germany so I wouldn't have to deal with him! Too many horror stories for this guy to risk his hard earned money.

[Make-a-Wake]

You went from roughly 36,000 rpms in the original setup to about 32,000 rpms in the twin, as Siberian pointed out. How do you expect it to go faster? The props can be larger due to the shared load. I hate to ask you to spend more money, but I think you need to try something in the Prather s240-s245 range, the are basically a 1.5 pitch and more diameter.

[GRAEME LOUW]

Wow you guys are fast !!!
Yes I have learnt about the fine experience !!!
If you were to give me a complete setup for the conquest for 120-130 km/h Would the Leopard 5692 / 98 be enough. Is the Neu 2215 a beter bet, but Neu states max Watts of 5000. This is slightly less than Leopard. I really cant afford to waste more dollars so I need to buy right this time. If it were you guys with all the experiance what would you go for from start to finish. From motor to prop as I really need as much info as possible
If you think the Neu will get my those speeds then I will buy from Steve.B I do have a Turgegy 240 amp HV ESC. Is that any good. All my batteries are Turnegy 45-90 C
Thank you so much for all the respose
Cheers
Graeme

[Fluid]

The Neu 2215/2Y is a great motor and would really pick up your performance. Another very good, high-quality motor is the Castle 2028. Both are much more efficient than the Leopards - don't believe what Leopard specs claim. A Castle 2028 just sold here on OSE for about $220 used, Steve is selling them for under $300 new. A club member used that motor in his Avenger and got 102 km/h with a small x455 prop. Running an x462 would put the speed in the mid-110s.



.

[RaceMechaniX]

Here was my build thread about my Conquest.

http://forums.offshoreelectrics.com/...-Cat-10S-Build

This is an excellent running cat for heat racing as does keep up with the gas boats. She runs about 72 mph for heat trim with an agreesive prop.

Tyler

[GRAEME LOUW]

Me Again. I dont think my last message sent last night was posted. Firstly thanks to all you guys for all the really great help and advise. I have taken your advise and will use a Neu motor from Steve but now do I go for the 1.5Y as you have used Tyler or DO I use the 2Y. My thinking is that 1.5 Y will give me about 38700 rpm on 10 cells and the 2Y about 28500 rpm on 10 cells. Is 10 cells enough ? 1.5 more RPM. Although I see Steve has no stock of the 1.5Y. Fluid you recommend the 2Y. My thought is that if I run 10 cells I can use the extra saved weight on mah for longer run times. Does this make any sense at all. What would be the very best ?
Would my Turgegy 240 hv ESC be enough or would I need to buy something else. I see Offshore has 240 Swordfish as well as 300 amp fully waterproof ESCs . Is this overkill

I need to buy right this time and not waste any more dollars. Even if I spend more now I just want a fast reliable set-up and you chaps seem to have got it ALL right
Thanks a lot
Cheers
Graeme

[GRAEME LOUW]

Another quick question.How is the Castle 2028 against the Neu 2215.
Will the Neu be quicker and more reliable ?
Does anyone have a Neu 2215 second hand for sale ?
Cheers
Graeme

[Make-a-Wake]

The 2028 is a fair bit more powerful than the 2215.......................probably 30-35% more if i had to pick a number.

[GRAEME LOUW]

A pic of my Conquest that was a single setup then the twin setup with TP Power and now I want to Neu it - PLEASE SEE PREVIOUS POST FOR PIC

[RaceMechaniX]

Graeme,

If you want the highest quality go for the Neu 2215 2Y or 2220 1.5Y. However the Castle 2028 is an excellent motor for the price. It works very well on 8S swinging gas props or 10S with smaller props.

Tyler