NEW CASTLE 1721 SPEEDRUN MOTOR

[Flames77]

I guess not. That’s straight from Castles website.

 

[Exc3l]

That could be a letdown for some buyers IMO. If I was a speedrunner and had a budget then I would not buy that motor. I know many speedrunners and drag racers here on this forum have sent their ESC's in for service at Castle and to know that mine would void the warranty if used with this motor would just kill me inside.......

 

[LibertyMKiii]

Raz posted up a few 190 mph runs and a 192 mph as the peak he could pull off with the 1721
Certainly more speed than I expected from this size motor and KV.

 

[Exc3l]

Raz posted up a few 190 mph runs and a 192 mph as the peak he could pull off with the 1721
Certainly more speed than I expected from this size motor and KV.

Impressive! Going to hit 200 in no time!

 

[K-BASH]

Looks like James is up to 180 on his 1721 talking about how bad the breaking is with it

 

[LibertyMKiii]

Impressive! Going to hit 200 in no time!

Having that runway is a big deal. He needed 3000+ feet to pull that off.
He had to let that motor wind up to 60k - 65k rpms (ignore what he shows in the logs)

Cannot emphasize enough to not over gear this motor. I was looking at setups over 150mph and you could do it with a 42t spur and a 24t pinion with this high of a KV. (using 2.8 ratio diffs)

 

[K-BASH]

 

[Exc3l]

Seems like getting to 180 is no big deal with this motor

 

[K-BASH]

Having that runway is a big deal. He needed 3000+ feet to pull that off.
He had to let that motor wind up to 60k - 65k rpms (ignore what he shows in the logs)

Cannot emphasize enough to not over gear this motor. I was looking at setups over 150mph and you could do it with a 42t spur and a 24t pinion with this high of a KV. (using 2.8 ratio diffs)

I imagine there's a super fine line between over gearing this motor.but if you get it just right I bet it's going to fly

 

[jondilly1974]

Seems like getting to 180 is no big deal with this motor

Getting to 140mph is a big deal These pros make it look easy. What James has done on that skinny road is amazing. Raz has the luxury of a private 4 lane runway with a gyro and it’s still very hard at that.

 

[Speed/267]

It's only 240$$$in stock.i need one

View attachment 176452

Ordered

 

[LibertyMKiii]

I imagine there's a super fine line between over gearing this motor.but if you get it just right I bet it's going to fly

Yes if people put in their Limitless 34/27 gearing it will burn up in a hurry. I suspect lots are going to do it too...

That is gearing with 2400kv for over 200mph

I bet some will try 34/34 also and really over do it....

 

[jondilly1974]

Yes if people put in their Limitless 34/27 gearing it will burn up in a hurry. I suspect lots are going to do it too...

That is gearing with 2400kv for over 200mph

I bet some will try 34/34 also and really over do it....

It also seems to lack braking power, so I bet there will be runaway fires

 

[Exc3l]

It also seems to lack braking power, so I bet there will be runaway fires

Isnt it braking that heats the motors up a lot?

 

[jondilly1974]

Isnt it braking that heats the motors up a lot?

Yep

 

[Exc3l]

Yep

I saw Raz's video with the 1/5 scale road car with the castle system and the ESC blew up because of all the braking with such a heavy car

 

[LibertyMKiii]

Isnt it braking that heats the motors up a lot?

Braking with speed gearing requires a ton of torque as does the acceleration.
Acceleration time you are putting 14,000 watts into the motor for 6+ seconds and around 10% is converted to heat.

That is around 1,400 watts of heat generation. Then add braking to that when it needs to be cooling down....

 

[Flames77]

Getting to 140mph is a big deal These pros make it look easy. What James has done on that skinny road is amazing. Raz has the luxury of a private 4 lane runway with a gyro and it’s still very hard at that.

Amen to that!

 

[K-BASH]

Somebody needs to come out with a parachute.ive seen it on drag cars.but going 140+ kinda chute.could also double as OH $HIT BUTTON!!!!

 

[LibertyMKiii]

Somebody needs to come out with a parachute.ive seen it on drag cars.but going 140+ kinda chute.could also double as OH $HIT BUTTON!!!!

https://www.ebay.com/itm/333901619720

You would have to re-engineer it for 120+ mph speeds with Kevlar strings etc...