Amperage Calculator?

[Rivermaxx]

You forgot to enter the differential ratio in briangs calc . Maybe it wants total finay gear ratio instead of just the tranny ratio?

Originally Posted by Rivermaxx

You forgot to enter the differential ratio in briangs calc . Maybe it wants total finay gear ratio instead of just the tranny ratio?

Even with that its 200 mph. If you want 100, go with a 15-18 tooth pinion.

[Rivermaxx]

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1.7222222222222223
Other Ratio: 1
Spur Tooth Count: 40
Pinion Tooth Count: 30
Total Voltage: 19.2
Motor KV: 2700
Tire Diameter (inches): 5,5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor Coil Resistance: 0.004
Spur/Pinion Ratio: 1.33 : 1
Total Ratio: 7.59544 : 1
Tire Circumference (inches): 15.71 inches (398.98 mm)
Rollout: 2.07:1
Total Motor Speed: 51840 RPM
Vehicle Speed: 101.52 mph (163.08 km/h)
Effective KV Value: 2700
KT constant: 0.5 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

Ok, i see what the problem is with the results in the amperage calculator. You werent putting in the diff ratio and the transmission ratio. I'm gonna have to add an input for the diff ratio somewhere. If you take the trans ratio times the diff ratio and put that into the transmission ratio on the amp calc, it should work.

1.72*3.308=5.69

[Rivermaxx]

I was told by Nic case when using the calc too use 3.00 v per cell not 3.7 v . I am using 3.2 and 3.30 :1 1/8 scale diffs. I come up with ~100mph. I have done this multiple times so I know my gearing is pretty close. I am just trying to figure out the amperage calc.

Originally Posted by Rivermaxx

I was told by Nic case when using the calc too use 3.00 v per cell not 3.7 v . I am using 3.2 and 3.30 :1 1/8 scale diffs. I come up with ~100mph. I have done this multiple times so I know my gearing is pretty close. I am just trying to figure out the amperage calc.

It looks like it will be around 200 amps. It will really depend on how fast you get up to speed. The faster you get up to speed, the more power you need. I assumed 8 seconds to get up to speed and you will cover about 700'. You can accelerate slower (9-10 seconds to get to top speed) and you can decrease your amp draw, but you will need a much longer runup distance.

[Rivermaxx]

Ok so it should be total gear ratio not just trans ratio. I thought that might be what the problem might of been. BTW this setup has been done with 25 pinion and 36 tooth spur with a lower gear 3905 tranny instead of a higher gear 3906 tranny and heavier revo and the best results were 91.2 mph on gps and radar.

[Rivermaxx]

Tire diameter is too tall I am running custom made foam tires that should have no tire growth. That look more like the results I am looking for though. Thanks

Originally Posted by Rivermaxx

Ok so it should be total gear ratio not just trans ratio. I thought that might be what the problem might of been. BTW this setup has been done with 25 pinion and 36 tooth spur with a lower gear 3905 tranny instead of a higher gear 3906 tranny and heavier revo and the best results were 91.2 mph on gps and radar.

Dont include the pinion/spur. Just put in the diff ratio multiplied by the transmission ratio and put it in the transmission ratio entry.

Originally Posted by Rivermaxx

Tire diameter is too tall I am running custom made foam tires that should have no tire growth. That look more like the results I am looking for though. Thanks

Ah ok. that will be much easier to control too. No pizza cutters!

So it should look like this:

Battery should output at least 200 amps.

[Rivermaxx]

I included the pinion and spur and just mutiplied the diff gear ratio x the tranny ratio and came up with the same numbers. Looks good now.

2 6s 5000mah 30c in parallel for 300 amps continues or 400 amp burst. Or is that overkill? I know it is heavy @ over 2 pounds just for batteries. I was also looking at 2 6s 3300 30c in parrallel for 198 amps continues and 264 amps burst also.

I think the 2 6s 5000mah 30c would be too much and too heavy.

I would go with the 2 6s 3300 30 c in parallel for 198 cont and 264 burst.

[Rivermaxx]

Question now should I get batts with 200 amp continues or 200amp surge?

[Rivermaxx]

Originally Posted by B4maz

I think the 2 6s 5000mah 30c would be too much and too heavy.

I would go with the 2 6s 3300 30 c in parallel for 198 cont and 264 burst.

I like that choice, I was thinking the same thing about the weight.