Going to take the plunge and convert my XB8EC

Hi Guys,

Been reading this forum for a while now and have finally decided to convert my nitro. Pls keep in mind that Im a complete newbie

A few questions that Im still not clear on:

1) Whats the best setup that I have now? I will be using the buggy mostly for bashing and the occasional race againsts the nitros.
2) Temps and humidity is very high where I live in (90F and 90%) so cooling is very important so Im guessing I have to run a larger motor to keep the temps down and cooling fans?
3) Whats the complete list of equipment/material that I have to purchase to make the complete conversion?

Thanks guys!

Tentative list of Equipment needed:

MGM Compro 160 amp, 18 cell brushless car controller
Electric Motor Mount - RC-Monster
Flight Power EVO25 5000mah 5s 18.5V Lipoly

Which would be better for a buggy if used for primarily bashing and occasional races?

Neu 1512 1.5D/F Sensorless Brushless Motor or Neu 1515 1.5d/F Sensorless Brushless Motor? Any other more appropriate motor?

Thanks!

[Patrick]

The first 3 items look good, and choosing a neu motor is also good, but the 1.5D's are a bit too high kv to use on 5s, especially if you live in a hot area.
I only have a truggy so I don't know exactly what would be better between the 1512 and 1515 for a buggy. Usually people with buggys use 1512's and people with truggys use 1515's, but that's not a set rule or anything.
The motor I have in my truggy is a 1515 2.5D (1700kv) on 5s, it works well and stay pretty cool. If you choose a 1515 for 5s I think the 2.5D is the best wind to choose.
Usually aim for 30 000 - 35 000rpm for racing to have a good balance of power and reliability. Neu's should still stay cool even if they're doing around 40 000rpm as long as it's geared right, but I'd still try and stay in the mid 30's. kv x volatage = rpm
eg 1700kv x 18.5v = 31450rpm That's only an estimate. Voltage drop of the batteries and how loaded up the motor is will affect what rpm it reaches, but it gives you an idea.
So if you choose a 1512 I'd look at the 3D (1700kv). The 1.5y (1900kv) or maybe the 2.5D (2000kv).

Oh, and welcome to the forum. I don't know why your post didn't get answer a bit sooner, that doesn't happen very often. Hopefully one of the buggy guys will be able to help you decide between the 1512 and 1515.

Thanks for the welcome Patrick. Guess the guys are out partying and celebrating the New Year!.

Btw, Happy New Year to you! Hope it will be filled with happiness and joy. Cheers!

Ok, after researching summore:

Tentative list of Equipment needed:

MGM Compro 160 amp, 18 cell brushless car controller
Electric Motor Mount - RC-Monster
Flight Power EVO25 5000mah 5s 18.5V Lipoly
Neu 1512/1.5y/F finned motor
Neu Rear endbell cover

Guys, will need some input on gearing for the buggy. Which would fit and be 'safe' for such a setup pls?

Thanks once again!

[Patrick]

Use this site made by BrianG http://www.scriptasylum.com/rc_speed/_top_speed.html
For racing 35-40mph is a good speed, depending on the size of the track, and the length of the races.

[jhautz]

I ran my buggy on the exact setup you listed with the exception of the motor. I was useing a Neu 1515/2.5/D finned or a 1512/2.5/D smooth motor and it ran fine on both. FOr the 1515/25.D I was able to run 18 pinion gears with no issue in the heat of summer, and with the 1512/2.5D I ran 15-16 pinions. That gave around 45mph for either setup. Giong down on the pinion size wasnt a problem on either setup if you wanted to slow it down a little for the track. Both setups ran fine heat wise and performace wise, but if you are truly worried about heat go for the 1515 it will run just a tad cooler but you will be able to make up the speed with the taller gearing.

The Neus are great motors, they run great unless you put them way outside their comfort zone. They arent like the feigaos that run ok if you get the gearing and load just right but if you move off of that perfect setup they just heat up like crazy.

The 160/18 runs cool and you shouldnt have any problems and 5s also helps keep the temps down. You should be very happy with that setup.

Thats my opinion anyway.

Since heat issues are very high in priority for me.

Fine-tuned selection of stuff needed:

MGM Compro 160 amp, 18 cell brushless car controller with Active cooling
MGM usbCom+
Electric Motor Mount - RC-Monster
Flight Power EVO25 5000mah 5s 18.5V Lipoly
Neu 1515/2.5D/F finned motor
Neu Rear endbell cover
18T pinion gear

Any other opinions on the selection? or suggestions pls?

Thanks in advance.

[jhautz]

I should probably be a little more clear about this. The buggy I was running was a Cen Matrix with the cen truggy dif gears in it. Cen uses some very strange gear ratios in the difs so the pinion gear choice does not translate directly to other buggies. The xray buggy(40/12) also uses dif gearing a little off from the standard (43/13).

By my calculations the pinion that will give you the equivilant overall gear ratio to what I ran would be somewhere between 16 and 17. Go wth the 16T pinion if you want to be on the temp safe side.

That should get you approx 40-45mph.

Other than that, I think the setup you have listed will make you very happy. They dont get better than that.

BWT: I just converted a xb8 myself and am really loving it. great buggys!

Since heat issues are very high in priority for me.

Fine-tuned selection of stuff needed:

MGM Compro 160 amp, 18 cell brushless car controller with Active cooling
MGM usbCom+
Electric Motor Mount - RC-Monster
Flight Power EVO25 5000mah 5s 18.5V Lipoly
Neu 1515/2.5D/F finned motor
Neu Rear endbell cover
16T pinion gear

Any other opinions on the selection? or suggestions pls?

Thanks in advance.

OK, Items ordered and on a flight now! w00t!

Will definately need more advice and help once the components are in and its time for the conversion.

Thanks to Mike for all the advice rendered too! :)

Final List of items ordered:

MGM Compro 160 amp, 18 cell brushless car controller with Active cooling
MGM usbCom+
MGM CC cable
Electric Motor Mount - RC-Monster
Flight Power EVO25 5000mah 5s 18.5V Lipoly
RC-Monster Battery Tray
Neu 1515/2.5D/F finned motor
Neu Rear endbell cover
16T pinion gear

[jhautz]

gonna be a sweet setup.

Guys, are these numbers accurate?


Differential Ratio: 3.33 (From X-Ray site: Primary Ratio) Correct figure here?
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 40 (From X-ray site)
Pinion Tooth Count: 16
Total Voltage: 18.5 (5s lipo)
Motor KV: 1700 (Neu 1515 2.5d)
Tire Diameter (inches): 4.5 (Standard 1/8 buggy rim/tyres?)
Tire Ballooning(inches):0
Motor Current Draw: 0
Motor coil Ω: 0.01
Spur/Pinion Ratio: 2.5 : 1
Total Ratio: 8.325 : 1
Tire Circumference (inches): 14.14 inches (359.08mm)
Total Motor Speed: 31450 RPM
Vehicle Speed: 50.57 MPH (81.24km/h)
Effective Speed Rate: 2.73mph/V (4.39kmh/V)
Effective KV Value: 1700
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...

If its fairly accurate, I will be getting about 50mph!!!!!

From X-Ray:

Pinion Spur : 12/40 (will be changed to 16/40 with new pinion)
Primary Ratio : 3.33:1
Internal Ratio : 3.54:1
Final Gear Ratio: 11.79:1

Did I plug in the right values pls?