Kyosho buggy motor recommendations

[kulangflow]

So, I purchased mwry's Kyosho buggy roller. It's so friggin' cool.

I have a Mamba Max ESC, CC BEC, HS-5955TG steering servo, and 4s 6K MaxAmps lipos to power it. Now I just need to figure out which motor to buy and the appropriate gearing for it. I'm looking for decent runtime, manageable temps, and 35-40 mph speeds. Should be doable right?

mwry used a 1515 1y/f Neu motor at 2200kV on 4s, but I can't quite justify a Neu for bashing. I'm thinking an 8XL might do the trick geared 15/46.

Assuming my numbers are right:

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 15
Total Voltage: 14.8
Motor KV: 2084
Tire Diameter (inches): 4.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0.0073
Spur/Pinion Ratio: 3.07 : 1
Total Ratio: 10.14359 : 1
Tire Circumference (inches): 14.14 inches (359.08 mm)
Total Motor Speed: 30843.2 RPM
Vehicle Speed: 40.71 mph (65.39 km/h)

Thoughts/suggestions?

Thanks!

[BrianG]

An 8XL would be fine for 4s. But, if you did go with a Neu, a 1512 is PLENTY strong enough!

[kulangflow]

Do you think a 15T pinion would be a good place to start with an 8xl on 4s?

[lincpimp]

Looks good to me. I have a hyper7 pbs going together with an 8xl on 4s thru a mm. I will gear 16/46, as I have the pinion handy.

[kulangflow]

Do you think the 7XL would be too hot?

It looks like 4s would put it at about 35K rpms, which is typically more ideal than the 30K rpms with the 8XL on 4s, right?

[lincpimp]

I would stick with the 8xl, it will run cooler and be easier on the lipos you have. The 7xl needs a really good battery to perform at its best. I have a few that I run with trakpower lipos, and they work fine. The maxamps 5k and 6k packs I had did not do as well as the trakpower. Plus the 7xl is more gearing sensitive than the 8xl.

[GO-RIDE.com]

I have a question to add to this topic. I know the 1512 on 4S is very popular for 1/8 buggies, especially the race crowd. I was under the impression that a 1512 is similar to an L can motor. Would a Feigao L be enough on 4S, or does the lesser efficiency of the Feigao motors require going up to an XL for even a 1/8 buggy?

[kulangflow]

Originally Posted by lincpimp

I would stick with the 8xl, it will run cooler and be easier on the lipos you have. The 7xl needs a really good battery to perform at its best. I have a few that I run with trakpower lipos, and they work fine. The maxamps 5k and 6k packs I had did not do as well as the trakpower. Plus the 7xl is more gearing sensitive than the 8xl.

Right on. Thanks for your help! (to you too Brian)

[BrianG]

Actually, the 1512 is more powerful seeming than an XL from my observations. My Revo (9XL on 14 cells) and buggy (1512/2d on 4s) weigh about the same RTR and the buggy is geared much higher, stays cooler, and has more oomph. Comparing an L motor to a 1512 is not even close to fair.

[GO-RIDE.com]

Wow you either have a crazy light Revo or a mega heavy buggy, and of course things like wheel weight and diameter play a huge role in acceleration characteristics. Gearing alone will not close the gap between two equally weighted vehicles, but one having much large and heavier wheels. All that aside, what would be an optimal race motor for a 1/8 buggy? Both Neu and Feigao? (Edit: both on 4S)

On other forums I read some guys switching from 1512s to 1509s for their race buggies, but some guys on this forum are using 1515s on buggies. That seems to be a huge gap. I assume the 1515 is really for the 60mph jump over my house buggy, and the 1509 is pretty much a race only motor, leaving the 1512 as a balance between the two.

[rschoi_75]

Originally Posted by BrianG

Actually, the 1512 is more powerful seeming than an XL from my observations. My Revo (9XL on 14 cells) and buggy (1512/2d on 4s) weigh about the same RTR and the buggy is geared much higher, stays cooler, and has more oomph. Comparing an L motor to a 1512 is not even close to fair.

I'd agree. I recently switched out an 8xl on my buggy for a 1512/2.5d. Same results.

[BrianG]

Both are around 11lbs RTR.

The 1509/1512/1515 are really all the same except for the can/rotor length. For a given turn count, greater motor length will give you lower kv (more torque) and cooler running (more surface area). The 1515 could probably go forever without ANY kind of heat issues at all and has the torque to be geared for VERY high speeds if desired. The 1509 is good for racing since its lighter and any weight savings can help. The 1512 is just a good compromise between the two IMO; is fairly light and can still be geared high if you want to go faster than 35-40.

[GO-RIDE.com]

Cool, thanks Brian!

[Arct1k]

iirc the castle neu is based around the 1512...

[GO-RIDE.com]

Yeah, at 2200 kv and for around $300 w/esc I may have to wait another 6 months... I mean 6 weeks until it comes out. Like others, I doubt it will be as efficient as a "true" Neu, but I hope it will still be good enough.