Want to prop up without drawing too many amps, help?

[midnightsabotage]

Hello,

I rebuilt an old stock SV27 (build thread link in my signature) and since there was no motor in the used hull I bought, I dropped in a new 1800kv AQ motor.

I'm still running the older stock 45amp esc that came with it, however. I was wondering if anyone could estimate how much I can prop up without worrying about overdrawing the esc?
I'm running pairs of 2s Turnigy 5000mah 5200mah 30/40c packs, and pairs of 2s 6000mah 25/35c packs. 5.5 bullets on the motor wires but still deans on the batteries till I get around to swapping them. The packs for my other boats have 5.5's.

I've just got a 40mm carbon prop now -1.4 pitch.

Would 45 be too large, or should I just go with a 42?

I've got 2 cooling intakes, running separate cooling on the motor and esc. I think the intakes are like 3.8mm inside diameter and 4mm cooling tubing throughout (3mm inside diameter?). Temps are pretty cool with the 40mm prop, but I can't really get an unloaded amp reading from the boat when running to know what I'm really pulling.

I know the easy answer would be to upgrade the esc, and I'm sure I will. But I figure I only have a couple more runs this year anyhow (if I'm lucky) & I'd rather spend the money on that over the winter or in the spring.

Either way, I'd really like to keep my esc from burning up, hence why I'm asking first before going by trial and error.

Thanks for any info,
-Jeff

[leeuk]

Ive heard that the 42 &45 are fine on stock escbut maybe pushing it with a 48,i just bought thr seaking 60 amp version 2 from kintec and stock running gear didnt even get it warm so easily more scope with that,ive a cf40 to try on her now and a cf42 &45 on there way from ose so will let you know how i get on mate

[siberianhusky]

I haven't tried it yet, but the next one I will try is a M445 on my stock setup, I've run 440/3, x442, x440, Prather 215 and I'm not sure which GrimRacer prop, belongs to a buddy, probably the 42mm metal one.
The holeshot with the 440/3 is wild, I can roll the boat over from a standstill if I just punch it. Awesome acceleration and my favorite prop in rough water, still looking for the ideal smooth water prop.
The 215 only did one lap before I brought it in for a prop change, same with the x440.
Temps have been good even in 100* August weather, dual cooling intakes.

[midnightsabotage]

siberianhusky, is your stock setup the older blue motor (1500kv or something like that...), or do you have the newer stock SV27R setup? i.e. the 1800kv AQ motor?

Thanks!
-Jeff

[siberianhusky]

Blue can, lots of torque with those motors. No real idea of the KV, seen too many different numbers!
My buddies with a UL-1 motor is turning a grimracer 42 I think. Boats are very evenly matched, we can't catch each other doing laps unless someone makes a mistake.
Think he is using an Aquastar 90 or a T-120.
Not sure what he is running on his other SV that also has the blue can motor.

[siberianhusky]

Oh ya, in race trim, with other boats on the water we are running about low 40's very high 30's. We're not too worried about top speed, it's enough of a challenge to be fast enough and finish 3.5 minutes of laps with your boat right side up.
The SV is probably one of my favorite boats, 3 or 4 on the water at the same time makes for some great racing, you really have to drive them and watch the wakes of other boats. They don't call them Super Flips for nothing!
We're building 1/4 scale Kneeler hydros this winter, another drivers boat! They look like a real hoot to drive.
All my boats are limited or spec powered, I really enjoy the tuning aspect of running boats, I personally get a bigger kick out of making a spec boat a little faster through tuning than just throwing more power at it and making it 10-15 mph faster.
Thats what's great about this hobby, there is something for everybody from the hardcore speed freak to the guy who just wants some relaxing fun off his dock at the cottage.