Upgrading the SV27???

[Fruity]

I am thinking of upgrading the drive system in my SV27, now the question is do I go for the 8XL that seems very sucessful in this boat?

or

Does the 7XL work in this hull as well, is the extra KV an advantage or disadvantage?

The reason I ask is the Ammo 2300kv seems to also be a popular choice, and is very similar KV to the 7XL but the Ammo being shorter will probably not be quite as strong as the 7XL.

I am running 2 x Rhino 4900 2S lipo pack for the 14.8 volts.

Also what is the optimum prop rpm (roughly) that I should aim at when choosing a set up - or when do they start not being efficient, 30,000 - 35000 - 40000 rpm ?


The stock set-up = 1800KV (approx) x 14.8 volts = 26640 rpm
8XL = 2073KV x 14.8volts = 30680 rpm
7XL = 2382KV x 14.8 volts = 35268 rpm
Ammo - 2300KV x 14.8 volts = 34040 rpm

The question is what would I ilke the boat set up for, I would like to set up for SAW for a short while just to see what it can do, but then once I have gone pretty fast, I would probably de-prop slightly to have a good fast fun boat. - I do not race - yet.


Any help would be great appreciated.

[skibo2]

Fruity

FWIW, I do not recommend the Ammo 2300 if you are looking for all out speed. I burned out two of them in one day. The first motor I was running a M-445 prop and a Castle 120 ESC and the motor only lasted three minutes and it burned up. I then installed a new motor and went down to a CF 40mm prop and it was okay but the speed only GRS at 41 mph. I then installed a CF42 mm Prop and GPS at 43 mph. Then went back to the 445 and quickly burned out the motor again. I am now running the Hydra 120 ESC, 8XL motor with 6000 mah Lipo's and a CF 45mm prop and GPS at 48.8 mph and the motor temps are super cool (103 max). I have only had the GPS in the boat for one run and have since made drive angle adjustments and weight adjustments and I know the boat is much faster than the original 48.8 speed. Sorry I don't have any knowledge of the 7XL but I can tell you this, the SV is not a light boat and needs the torque provided by the lower KV motors to allow you to run a higher performance prop.