backyard basher
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I want to install the castle 2250kv and mamba esc to run 4s lipos.what gearing would I need as I have no pinion yet for the motor.the spur is stock. It’s a slash 4x4 ultimate
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id say 14 or so. but dont take my word for it, yet.
Tunedfrog
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I make it a point to purchase pinions in sets. It's a bit more spendy but no big deal.
That way you can start out low and work your way up so you can find the happy medium between speed and too much heat.
That way you can start out low and work your way up so you can find the happy medium between speed and too much heat.
9x19
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4S ~ 14.8V x 2250kV = 33,300 rpm
3S ~ 11.1V x 3500kV = 38,850 rpm
Traxxas suggests 19/54 as the top for 3S, so I'd say 17 or 18 to start.
That lager motor is probably gonna have more torque than the 3500kV that comes in the Slash, so I'd go easy on the rapid acceleration until you're sure the gears can handle it.
3S ~ 11.1V x 3500kV = 38,850 rpm
Traxxas suggests 19/54 as the top for 3S, so I'd say 17 or 18 to start.
That lager motor is probably gonna have more torque than the 3500kV that comes in the Slash, so I'd go easy on the rapid acceleration until you're sure the gears can handle it.
backyard basher
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That sounds like a starting point.i was thinking 13 or 14
9x19
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I think 14/54 is stock gearing, so you're not wrong.
Cumi511
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I just put in a castle 2650kv on my slash 4x4 with the mamba monster and had the exact same question. Only hitting around 50 mph on some hoons tires with 22 gear and 50 center diff. Went to 54 center diff with 22 got to 58 on 3s and was expecting a lot more…CC won’t give me an answer
All though they told me 2650 was the best bet for speed so figured I’d bring it up here.
Ramp addict
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A 3500kv with a 11t = 2250kv with a 17t. The formula is too simple to be exact but it is close. I've never had good luck with 1/8th scale motors in my slashes. Mine suffered from never ending driveshaft issues. I think a Castle 1415 on 3s would be a better choice.
9x19
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If you're just looking to build a speedy Slash, going down in kV (revolutions per volt) seems the wrong path to me.
I'd think going up in kV (4000) would be a better starting point. Given the same number of battery cells (2S or 3S) you're going to get higher RPMs over the stock 3500 kV. You'll give up some low end torque vs the 2650 kV motor, but that isn't a great loss for a speed runner, IMO.
I'd think going up in kV (4000) would be a better starting point. Given the same number of battery cells (2S or 3S) you're going to get higher RPMs over the stock 3500 kV. You'll give up some low end torque vs the 2650 kV motor, but that isn't a great loss for a speed runner, IMO.
