Anyone changed the gearing on Arrma Granite

Darren Wes

Well-Known Member
Messages
306
Reaction score
163
Location
St. Louis
Arrma RC's
  1. Granite
Was looking last night for a blx gearbox... it seems as if I can just buy the blx metal diff case and gears plus the metal shaft and it would be a blx by the time I put in the 39kv 4pole.... has anyone made the mega blx switch... anyone know if its that easy
 

Blxer

Well-Known Member
Messages
231
Reaction score
129
Arrma RC's
  1. Granite
@Darren Wes, don't forget the aluminum motor mounting plate! Unless, yours has one already? As heat, will be an issue with the new setup. I'm still learning alot myself, the most important thing I've learned, heat is an rc's worst enemy! Well, that and my 5yr old!
 

Darren Wes

Well-Known Member
Messages
306
Reaction score
163
Location
St. Louis
Arrma RC's
  1. Granite
Well my diff is out of commision. I decided to not do any more 3s untill i can put a metal jacket inside the gearbox. The gears seem ok the 32p helps, but im sure i just was wailing too hard on the diff. Unsure if there is an easy fix but im gonna just let arrma fix it for me this time then next i will do simple replacments and try heavy diff oil see if that helps..if not. Will have no choice but to go full metal. in the mean time i finally waterproofed the hobbywing stuff in the granite. Seems like it will hold up.... also tuned up my 18t... runs great. Gotta figure out the cheapest way to make a mega accept the blx style motor
 

Dustin Mustangs

Well-Known Member
Messages
609
Reaction score
431
Arrma RC's
  1. Granite
I noticed that if you put on the (blx) option spur (54t) with the stock pinion (13t) it lowers the gear ratio (and raises top speed) by 5%. I haven't tried it yet but that should make for a noticeable increase in speed and also make switching to the high speed 3s gearing a lot easier. One of these days I will gps it both ways to see how much it actually changes.

Here is the gear chart from the tuning manual: Capture.JPG
 
Last edited:

Darren Wes

Well-Known Member
Messages
306
Reaction score
163
Location
St. Louis
Arrma RC's
  1. Granite
I have no idea what transmission i have..i got NIB rolling brushed Raider
Hummm... well i guess ill have to wait till you do some maintaince to find out.

People have done many things with the mega transmission seen hpi swaps, seen blx upgrade stories, seen part transfers with traxxas.

Would really like to see someone take the rpm high performance stampede transmission upgrade swap with arrma transmission, looks like it could be simple... would also make parts easier to obtain for it.
 

Darren Wes

Well-Known Member
Messages
306
Reaction score
163
Location
St. Louis
Arrma RC's
  1. Granite
I did a motor swap from the 2pole 39kv to a 4pole 39kv and decided i am going to put on a 13t 32p pinion and 54t 32p spur.

I encountered unwanted heat issues within 10 min. With stock 15t/87t. And i think this is the best idea.
 

Walter

Well-Known Member
Messages
278
Reaction score
208
Arrma RC's
  1. Fury
  2. Granite
I did a motor swap from the 2pole 39kv to a 4pole 39kv and decided i am going to put on a 13t 32p pinion and 54t 32p spur.

I encountered unwanted heat issues within 10 min. With stock 15t/87t. And i think this is the best idea.

15/87 is a 5.8:1 gear ratio. Moving to 13/54 will be 4.2:1 which is probably going to make your heat issues worse. It's possible that with the new motor that you are undergeared so severely that you need to gear up. But typically you would gear down for heat issues, which is the opposite direction from the change you are proposing.
 

Darren Wes

Well-Known Member
Messages
306
Reaction score
163
Location
St. Louis
Arrma RC's
  1. Granite
I guess i would wanna just change to 13/87 then. Thanks for the heat heads up. Imma add 2 fans and the metal motor mount somtime soon. Hope that will chill it out on 3s a bit more
 

Darren Wes

Well-Known Member
Messages
306
Reaction score
163
Location
St. Louis
Arrma RC's
  1. Granite
Oh and a heatsink for the motor.. could have been since yesterday was 100degrees i could have gained most of my temp from that
 

BigSplit

Well-Known Member
Messages
194
Reaction score
155
Arrma RC's
  1. Granite
  2. Talion
Anyone know if there are spur gears for the 2013 blx with a lower tooth count then stock 87t? Or a way to convert it to another brands slipper clutch setup so I can get a smaller spur? Or a way to convert pitch to the newer?
 

Unusual RC

Premium Member!
Premium Member
Messages
815
Reaction score
309
Location
The Hague, The Netherlands, Europe
Arrma RC's
  1. Fury
  2. Mojave
Anyone know if there are spur gears for the 2013 blx with a lower tooth count then stock 87t? Or a way to convert it to another brands slipper clutch setup so I can get a smaller spur? Or a way to convert pitch to the newer?

The BLX has 54 or 57 teeth on it's spur gears. 87t is for the MEGA version. Have not found a different brand replacement yet.
 

Walter

Well-Known Member
Messages
278
Reaction score
208
Arrma RC's
  1. Fury
  2. Granite

BigSplit

Well-Known Member
Messages
194
Reaction score
155
Arrma RC's
  1. Granite
  2. Talion
The BLX has 54 or 57 teeth on it's spur gears. 87t is for the MEGA version. Have not found a different brand replacement yet.
grrrrr, I definitely have the blx. The guy who I got it from printed out the wrong manual and I didn't notice. I just counted the teeth on my broke spur and it's 57t. Which means the 87t I ordered is worthless...lol
 

BigSplit

Well-Known Member
Messages
194
Reaction score
155
Arrma RC's
  1. Granite
  2. Talion
It came in right after I posted..Lol It fit the shaft and I have a 19t 48p pinion on hand that fit the motor shaft. I ran it for two seconds and there's something wrong inside the gearbox/trans. The shaft is coming out a good 1/4" stopping the pinion from touching the spur. A couple of broke teeth on the new spur because of it.
 

Unusual RC

Premium Member!
Premium Member
Messages
815
Reaction score
309
Location
The Hague, The Netherlands, Europe
Arrma RC's
  1. Fury
  2. Mojave
You have no luck with your car BigSplit :(
I have a spare BLX gearbox here in my hands, and the only way to get this axle 1/4" (6mm) sticking out is having no bearing on the right side...
I am afraid you have to open it and see what is going on.

Indeed practically all the 2013 BLX and MEGA parts are completely interchangeable. The 48p set-up has too small teeth to cope with 4-pole brushless power.
 

BigSplit

Well-Known Member
Messages
194
Reaction score
155
Arrma RC's
  1. Granite
  2. Talion
Lol, now I stripped the screw in the 48p pinion. I can't get it off..Lol
 
Top