Granite Arrma Granite 4x4 Mega - Brushed to Brushless Motor Upgrades

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Leewilson7

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Hi all. New to the forum and have found many discussions on this topic that come from different questions across other threads. Let us hear how you’ve upgraded your Granite Mega to a brushless system and any regrets you might have. Please keep in mind that there are many of us newbies out there that can really use some help. Please try to be specific when listing upgrade parts you’ve used.

Thanks for your help!!! Hope this thread becomes helpful for lots of newbies like me.
 
First thing we broke was motor and spur gear.

There were no 48P spur gear replacements available.

We got a blx slipper clutch with 32P 57T spur gear.

Had to modify rear diff input because the adjustment screw on the blx slipper sits proud inside the sleeve that connects to the input. That consisted of drilling out the middle of the stock plastic input a bit to make clearance.

Went to a 12T pinion that fit out new 550 motor's 3mm shaft.

Had to purchase an adjustable motor mount. Got locking washers and thread locker. Other things required: slipper clutch axle. A splined red aluminum thing that is just a shorter slipper clutch axle shape exactly like the stock mega axle except no thread.

Forgot to get that at the store and ended up cutting the stock one with a grinder and filling it smooth.

Back on the road!

Motor smoked.

3rd motor.

Went to a 9T spur gear: with the 57T 32P 3s spur gear that gives you nearly the exact gear ratio as the stock 48P 14T pinion and 91T spur.

Put the Lipo away and run on Nimh battery. ! Success!

Bought max10 sct combo.

Got a 15T 32P 5mm pinion to fit the larger motor shaft of the 3660 hobbywing ezrun 3300 kv motor. And a 20T.

Put the 20T on.

Go to 2S. Set the ESC to no reverse and always 2S because one battery.

Holy poop! Stock tires ballooning like crazy!! Thing is a rocket ship! Getting like 50 mph. Doing speed runs on asphalt. No off roading.

Preloaded front and rear shocks double to improve cornering and prevent barrel rolls.

Esc mounting plate exploded. Crazy glue and plastic cement it in place. Get flat washers and locking washers for those screws that hold the cover over the receiver and hole mounting plate down.

Upgraded wheels and tires. They wobble. Six pack st duratrax 14mm hex. Maybe avoid. Wish I had done more research but they look bad ass and perform great.

Got sealed bearing kit.

Next: tighten slipper clutch, replace bearings: destroy diffs. Have the tougher BLX diffs and inputs in the post. Rear diff is making noise. Probably missing a tooth somewhere. Still running.

Maybe going to go thicker oil in shocks.
Got a castle creations fan for the motor. Simple affair. Zip ties to the motor.
https://jennysrc.com/products/arrma...ear-slipper-clutch-assembly-diff-57t-ar102668

https://www.arrma-rc.com/part/AR310898

https://www.hobbywingdirect.com/products/ezrun-max10-sct-combo

https://www.spektrumrc.com/Products/Default.aspx?ProdID=SPMXCA302

https://www.canadiantire.ca/en/pdp/weller-professional-260-200w-soldering-gun-kit-0586368p.html

https://www.ebay.ca/itm/Arrma-TYPHO...ear-37t-Granite-senton-AR102696-/333007804674

https://jennysrc.com/products/arrma...put-bevel-gears-13t-bearings-granite-ar102668

http://www.castlecreations.com/en/cc-blower-for-36mm-motors-011-0014-00
 
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i upgrate it with hobbywing ezrun max10 combo 4000kv 120A 3660 (you need to buy new pinion because motor has different diametr). i don't have any problem yet with using lipo 2s. Maybe if you use lipo 3s you will damage differentials but i am not sure. My opinion is that you need a better servo and ofcaurse you must upgrade shocks because they have very low quality. I am thinking to upgrade my differentials with granite blx diffs because i believe they are stronger
 
anyone have thoughts between these

https://www.amazon.com/38010200-Max...62c1683bfb&qid=1595097180&sr=8-4&tag=arrma-20

http://www.castlecreations.com/en/4...-1410-3800-5mm-sensor-ready-motor-010-0164-06

Or just go with the stock blx motor and esc.
Trying to learn here. Why select the 4000kVinstead of the 3200kV motor?
i upgrate it with hobbywing ezrun max10 combo 4000kv 120A 3660 (you need to buy new pinion because motor has different diametr). i don't have any problem yet with using lipo 2s. Maybe if you use lipo 3s you will damage differentials but i am not sure. My opinion is that you need a better servo and ofcaurse you must upgrade shocks because they have very low quality. I am thinking to upgrade my differentials with granite blx diffs because i believe they are stronger

Trying to learn here. Why select the 4000kVinstead of the 3200kV motor?
 
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Between the two combos you linked I would go with the hobbywing combo because it is 4s capable and has proven to be a solid combo. The castle sidewinder combo is only 3s capable and the only real benefit over the hobbywing is it has data logging capability but that really isn't something you need for a basher, imo. Warning tho don't go 4s in a mega conversion unless you convert all the gearing front to back with blx ones.

Trying to learn here. Why select the 4000kVinstead of the 3200kV motor?

KV = motor RPM per volt.

Higher KV equals more RPM per volt aka faster top speed but the trade-off is lower torque compared to a lower kv. Lower torque = slower acceleration and motor has to work harder to move the vehicle.

Think of it like gears in a car where 5th gear gets you 100mph but if you started in 5th gear from a dead stop the engine would die or take forever to get up to speed plus the engine has to work really hard to get there.

Imo the sweet spot for kv for the 3660 sized motors running 2-3s is 3000kv to 3500kv. For bashers better to have enough torque and gear up your pinion to get more speed if needed.
 
i upgrate it with hobbywing ezrun max10 combo 4000kv 120A 3660 (you need to buy new pinion because motor has different diametr). i don't have any problem yet with using lipo 2s. Maybe if you use lipo 3s you will damage differentials but i am not sure. My opinion is that you need a better servo and ofcaurse you must upgrade shocks because they have very low quality. I am thinking to upgrade my differentials with granite blx diffs because i believe they are stronger
Yeah! Absolutely. Like the transmission the pitch on the differential is smaller: fewer larger teeth. Much tougher.
Also: steel input for differential.
 
Great topic and thread! I have a 3900 kv Brushless motor and I can't run anything higher than the 14 tooth pinion otherwise it cogs and is slow to take off. I've been thinking of going with something like a 3200 for more torque or just switching out my diffs for the BLX which have less teeth on them. I would probably have to change my diffs out eventually anyways. I would just have to change both diffs and both input gears.
 
Update on my Granite upgrade from brushed to brushless. I switched out my esc to a Surpass 60 amp and no more cogging on takeoff. I'm running 50c 5200 2s lipo. I also have a 17 tooth pinion in it. It's plenty fast.

My only issue is that my esc fan blades keep bending up to where they make contact with the fan cover and the fan stops working. I then have to remove the cover and use snips to cut away the part of the blade that is sticking up. This is just from running on asphalt and grass and doing some mild jumps. Could this be caused from vibration? The esc is firmly glued down to the top of the receiver cover. I know that fans are cheap but this happens on every single run. Maybe it's possible that the plastic blades are melting from the heat. Are there fans that have aluminum or metal blades?

So glad though that I figured out the cause of the cogging.
 
hello. i have a senton 4x4 mega and am also looking to convert to brushless to get the most out of my arrma! as @Leewilson7 mentioned, the max10 combo looks like the perfect thing to go with, but do I need to upgrade the gearing front to back to the blx gearing? and what pinion gear should I use for this motor?
and also, I am a newbie so please add links when mentioning upgrade parts! thx:)
 
thx so much!
The 20T I put in my typhon. I maybe would not do that with a granite or Senton. I believe the Senton is a 17T pinion. I would stay there. The 20T can overheat my typhon. We ran a 20T for a bit in the granite but went back to 15T. I think it is mostly about the weight of the wheels the motor has to push. We stayed with the plastic spur because we have to shred 6 of them to equal one metal one and we're less likely to break the pinion and other stuff. Better to leave a known weak point that is easily replaceable.
We got these batteries.

http://www.spektrumrc.com/Products/Default.aspx?ProdID=SPMX50003S100H5

Crazy performance.
 
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