Genesis build failing

[Juraj]

Hello everyone , this is my first thread but have been following for a long time.

I have built a genesis with a single drive with a tp4070 1770kv, hk180 esc, 2x 3s 4250 65c lipos series and a 1.9x 48 3 blade prop.
im running 78km/hr / 49mph.
now im wondering why its so slow... i have no data logging so im not sure what amperage its running, but the system doesn't get above 50degrees.
It could be just because i have a fairly large cooling system which im thinking may be the issue, causing too much drag.

I know there is a lot of guys here who have built these boats , please help
i would like to be running around 60mph or faster.

thanks
IMG_20140724_204353[1].jpgIMG_20140724_204521.jpgIMG_20140724_204545.jpgIMG_20140724_204605.jpgIMG_20140724_204614.jpg

[srislash]

Explain 'failing'?

[Juraj]

oh well then i forgot to add in the story

[Juraj]

the ose calculator says i should be over 85mph... i know its not perfect but i would of thought it would be somewhat close

[srislash]

You shouldn't have any problem hitting 60 with that setup. First off, you in no way have enough battery for that 4070. Double the mah's and you will see an increase in speed.

[sapdforu]

A friend has one that went hi 60's with stock motor, a video may help some.
My stock genesis never did run well, it acted like it plowed and never got on top of the water, so there may be something going on that words are hard to explain.

[srislash]

Any chance you can tell the COG? This is the measurement from the end of the ride pads to the point which the boat balances on something. A dowel or something like that placed under the boat from side to side will do this. It should be 30% or so.

[Alexgar]

to much prop pitch, to small of batteriesand maybe the prop is to low I can't tell from the.picture

[kfxguy]

Not sure you need a skeg type strut like that, extra drag. Then those water inlets have to be causing mad drag. Your strut looks too high but it's hard to tell because the whole boat isn't in a pic. If it's running wet it will be slower too. The esc or motor could be partially defective also. Not likely, but possible

[srislash]

to much prop pitch, to small of batteriesand maybe the prop is to low I can't tell from the.picture

Can't tell how much the prop centreline is above or below the ride surface. Alex does bring a valid point with the pitch too. It could be lifting the rear. It depends on the boat. My lightweight Geico hates pitch but my Fantasm seems to be good with it.

[iop65]

those waterpick ups ,they act like an anchor
just drill hole in the sponsons(last ones) , glue a aluminium tube ( 4- 5mm) in an 45° angle pointing backwards and sand the tube till it doesn't stick out off the sponsons: will make a big difference and is way sufficient to pick up water

then those small lipo's with the xt-60, in an harnass connection, small/little wiring : it's a bottleneck for the amps Juraj

hard to believe that those connectors and wiring aren't getting hotter then 50°C with that motor and prop

[Juraj]

thanks for all the replies !!!
so the cog is at 10" from the end of the ride pad, so that seems about right. i did have a 5s 10000 mah before but it seemed to sit quite deep in the water like the hull couldnt handle the weight, but yes now it does seem to jump right out of the water on acceleration , maybe it does need some more weight, everything in the back is is super sharp and rounded including the skeg and the ruder.
the strut is, well the round part of the strut so imagine it without the extra skeg on the bottom, is even with the ride pad, does have a i would say 1.5 - 2 degree negative angle.

[Juraj]

The connectors are tx90s not 60s but yes i agree they are somewhat small and the wires are all 10G
I'm waiting for my new 8mm connectors to arrive. As far as i can tell these tx90 connectors aren't getting very hot at all.

[iop65]

looking at the 10awg wiring :those xt-90 connectors must be big !
and still 4.5 mm plugs

[martin]

To much prop for your set up, 3.58" of pitch + 3 blades with motor at 39,000rpm unloaded.