turb06le240

iTrader: (14)

Hey tony I have another ?
Where should I start with the pinion size?
I am doing the mbx5t egea useing the mbx5 spu gear and the buggy size tires, with a 4.5hv??????
Thanks
Im useing the 5mm rotor in the hv, with the new novak geas that match the spur gear on the 1/8th buggies, so I dont have a lot of them to play with ....

TonysScrews

iTrader: (13)

HV 4.5 = 4800/kv motor
10 NiMh Cells = 12.0v (10 x 1.2 = 12.0)
Ring & Pinion = 46/10T or 4:6.1
Spur Gear = 46T

Top RPM = 4800/kv x 12.0v = 57,600 RPM's

After doing the math, you would not want to run any more than 10 cells anyways as 57,600 RPM's would be pushing the motor's limits. A very cheap, lightweight alternative would be for you to run the 4000mah ProTek R/C 20C 11.1v 3S1P LiPo from Amainhobbies. I think the pack is like $85 and only weighs 292g. It'll be over 1-1/2 lbs lighter, will get much better run time, handle better, jump better, accelerate quicker, etc. Fully charged the LiPo will be 12.6v but will settle down to 11.1v quickly and then stay there most of the pack.

I would start with the 11T pinion which will give you a calculated top speed of 40.1 mph at 12.0v. The fastest nitro motor in a Mugen buggy with stock gearing is going to barely hit 43.0 mph. But that is using a LOT of room to get there. When R/C Car tested their nitro MBX5R it took well over 5 seconds to get to 40mph. My brushless MBX5R got to 40 mph in about 2 seconds flat

I think the 11T pinion would be your best compromise for run time and less heat. Any taller and I think you will run into thermalling issues.
But for the specs:

10T = 36.4 mph * would be my choice
11T = 40.1 mph * would be my choice
12T = 43.7 mph
13T = 47.4 mph

If you run into issues and decide to sell the HV 4.5 and go with the HV 6.5, it is a 3100/kv motor. Gearing would be as follows with 10-cell 12.0v pack in your car:

15T = 35.3 mph
16T = 37.7 mph * would be my choice
17T = 40.0 mph * would be my choice
18T = 42.4 mph

Best regards and best of luck,

turb06le240

iTrader: (14)

I had to read that about 4 times but I got it now, I got a great deal on the 4.5 [MOTOR, ESC, 5MM KIT FOR $200 all brand new}..
Thanks Tony, your the man, my next kit {which may be soon} will definetly be from you....
I made an offer on an RC8, well see what happens...

turb06le240

iTrader: (14)

What if I use 2s packs, would I suffer a ot of top end loss?

TonysScrews

iTrader: (13)

You can try the 2S packs, but the problem you're going to have is the less voltage, the more amps you're going to pull (especially if you gear it up to get the speed back out of it). I would personally go with the 3S and think it would be your best shot at making this setup work. Worse case scenerio, you can easily sell a 3S 4000mah 20C pack to anyone that has an electric Stampede, Rustler, Bandit, etc that wants to go 60+ mph....LOL

turb06le240

iTrader: (14)

The pack is the last thing Ill buy, I have to wait for the conversion kit anyway because they arent getting released until the end of march...
Tony, I was wondering, How would it work if I just took out the mbx5r's complete center diff assembly and replaced it with a B44 or BJ4 center slipper, with some basic grinding I could get the drives to fit, then I would have a slipper and be able to use regular gears...???? Would it work?

turb06le240

iTrader: (14)

Or is there a better center section to use?

TonysScrews

iTrader: (13)

Run the Mugen diff until a 1/8th purpose built slipper is out. Dan from RC Product Designs is making one.

turb06le240

iTrader: (14)

Sounds, good, Ill keep an eye on his site for the slipper, What gears match directly with the stock metal spur geat on the mbx5 1.0 module???

Cain

iTrader: (294)

Tony,

what advantages will we sill with the slipper versus the current center diff? Reason I ask is that I remember talking to guys who run both 1/8th and 1/10 scale buggy prefer the 1/8 scale enter diff setup to a slipper.

Right now for lightening my vehicle, I am looking at the mugen light pillow balls you can find on carolina's RC for $32. Anyone know if they are worth it?

turb06le240

iTrader: (14)

Ive never used the ones from carolinas, but the graphite ones from Lotta balls, are nice... There around $40, then there are titanium ones and aluminum ones rite from mugen....

TonysScrews

iTrader: (13)

Honestly, I have no idea how the center slipper will work (if it even works). I don't doubt Dan's ability to know how to make one, as he is VERY talented. But with the kind of power we are putting down with these Neu motors on 4S (plus the heavier weight of an 1/8th scale), it'll be very hard to find the right material that will handle the heat generated and not burn up. Strobe made a slipper for the Big Block superMaxx's back in the day and he tested several different materials for his Strobe Slipper. They worked well with the .21 motors, but once we started stuffing .26's and up, if the slipper wasn;t locked up, it would melt the pads real quick. These Neu motors make twice the power and we're talking about direct drive, not a geared down T-Maxx tranny.

Best regards,

turb06le240

iTrader: (14)

OK, so I ordered just about everything I need and IM just waiting on the conversion kit, but I seen some pics of other conversions and I noticed some o them have BECs, Will I need one of these, Im running the Novak HV, 3S lipo, 2 fans, and hs985mg servo.. I have a Fasst radio system with the 3 channel reciever and there is a bec plug, but IM not sure exactly what this does... If I do need one which one should I get? Thanks or your help...

Cain

iTrader: (294)

I would contact Novak to see.

The conversions you are seeing with a seperate UBEC most likely are mated with a Mamba Max ESC as its only rated to 3S with the internal BEC. when you eliminate using the internal one, you can do 4S with proper cooling (or, adding a nice capacitor to it from what I am hearing)


As for my conversion, I am planning to order the following:

1. Novak 2700 capacitor
2. MBX5 lightweight pivot balls
3. Titanium screw kit upper (maybe)