Neu 1512/1.5D in Buggy?
 

Will running a 1512/1.5D with 4S Lipo and Mamba ESC in a 8ight buggy be fine or will there be alot of heating issues? What gearing should I look at using?

Imo, 4s is too much for that motor in a buggy. You'd be down around a 9 or 10 tooth pinion and turning well over 40k geared for 40 mph. That is, however, the motor I intend to run in my next buggy on 3s. With 3s and a 14th pinion, you'd still be geared for 40mph and the motor would run much cooler. My guesstimations are based on Losi 8 but most 1/8 buggies have relatively similar gearing. Hopefully some other folks will chime in and verify or negate my opinions.......

1512/2.5d(2000kv) would be my choice if your determined to run 4s. I had a 1515/1y in my 8; It was definitely overkill.

Not sure about geering, but I do know that the neu's are better at high rpm (~45,000) than the lesser motors (i.e. fiegao's at 35,000) and people seem comfortable to spin them fast without concern. 1512 was what I want for a hyper7 but I'm holding out for the MMM package now...

I run the 2.5D and it's useable power and very smooth. top speed on 4s is pretty close to a good nitro well tuned but out of the hole it has grunt. I might try going up a tooth on the pinion, as I am running the RC8 and using the same gearing as a stock nitro. on a smaller track it is dominant but the larger track I was at on friday, I'd like more top end because the track is all about speed with high banked burms and a couple jumps you really need the speed to make...

next for me is a 2.0 to try. I know 2 guys here using the 1.5 on 3s. 4s was just silly power

My local track is fairly large, pretty sure 2 maybe 3 conrods have given way on the back straight.
Just worked it out, if I was running a 10T pinon and 46T Spur while running the 15D and 4S the ratio would be 15.22 and running about 55mph approx. which is more than I thought. If I ran 12T and 3S would be 12.68 with approx. speed of 50mph.
Do you notice I difference if you were running a lower KV motor with more cell lipo than a higher kv motor with lower cell lipo?

Lower kv and taller gearing = less load on the motor and lower rpm at top speed. A Neu will take rpm upward of 60k but for the least heat and best efficency you'd like to be running around the same rpm's as a nitro, mid to upper 30's. The enticement to run 3s is the weight difference between the 1515 and the 1512 as well as the 4s and the 3s. On 3s you could run a considerably higher mah pack and still have a much lighter car although it will run warmer due to higher amp spikes on the lower voltage. It's a tough call...

Ok, worked it out if I was running the 1.5D and 3S Lipo
http://i29.tinypic.com/3492vco.jpg

The tire diameter input is too large. A slightly worn crime-fighte is only about 110mm.

Brian's calc. shows around 35k and 40mph with a 3200kv motor on 11.1 volts with a 46 spur, 14 pinion, and 4.2 inch tires in an 1/8 scale buggy.

Alright, thanks, when I was on Tower Hobbies to check the size the Badlands were the 1st one to come up so I just used that size. Changing it to 110 makes big difference. Running a 4S on the same gearing works out nearly the same as the badlands
http://i28.tinypic.com/2u7o9kx.jpg

So I would be best off if running the 1.5D to run a 3S and run talling gearing like 14T or 15T?

http://i27.tinypic.com/2ekma15.jpg

That's the set up I would like to build next. I have'nt run 3s in a buggy yet but I can't imagine that it would'nt be competitive. I would post a question in the brushless section tiltled 3s/1512/1.5d in a buggy? and see if anyone else has comments on 3s buggies. You'll get more feedback in that section. Also, check out this calc.:

http://www.scriptasylum.com/rc_speed/index.html

Most everyone I've seen racing a 1/8 buggy conversion is using 4S. I've always read that higher voltage (lower kv motor) means cool electronics, less amps and longer run times per battery gram. I'm sure a higher kv Neu motor on 3S would be very fast too, but also draw more amps for a given speed and thus run both the motor and esc hotter. At least that's what I've been reading in this and other forums. Is there something I'm missing? I guess one advantage is the current ESC of choice (Mamba Max) can be run on 3S without an UBEC, but I assume it would run hotter due to the greater amp draw?

The other thing I've read is that two equal weight batterys (ie: same # of cells), but one is 3S and the other is 4S, the 4S will give a bit longer run times (even though the 3S has more Mah) because volts are more efficient than amps. Obviously, each has to have a motor that is optimized to its voltage for this to be a far test.

I'm getting ready to convert an 8ight so I've been reading up a lot on the choices out there.

I have been thinking of doing a 3S setup, currently running 4S, but with a 3S PQ6000XP 25C battery, it should be able to handle the amp draw I believe, with maybe slightly higher cutoff voltage. Just not sure exactly of the numbers to run to determine how it can handle it.

Perhaps im better off looking at the 1Y which works out to be 40700RPM with a 4S battery.

http://i27.tinypic.com/245d6yo.jpg

FWIW, I use a 1512 2d on 4s and it works fine. Even geared up on 46/16, the motor is perfectly fine and stays cool (even for me). I tried it momentarily on 6s and it still is fine, if too fast to control!

The Neus seem to not mind higher rpms. If you run a high rpm, just gear down a bit to keep things controllable. As long as you stay under 50k you should be perfectly fine IMO.

In my Ultra GTP project, I plan to run a theoretical 62k rpm on a 1515 (but the rpms won't get that high because of wind drag).