I don't wanna open another can of worms, but seeing that the engine compartment is pretty tight, how about gearing options?

Are there different pinions available and is there enough room to adjust the engine?

my memory says it's 1725g to be ROAR legal.... i think or should i say if my brain is working right :lol:

the engine didn't have to be moved when changing gearing options with my mtx-3 unless of course you were putting a really worn out pinions and spurs -- then you may have to tighten it a bit. but as far as moving the motor every time you change the gearing... it's not needed at all. the mtx-4 should be the same way because it's the same gearing (0.8)

Hi Jo and Stefan,

First gear, 16-18 58-60
Second 21-24 52-54

:D

what's the stock gearing on the mtx-4?

17/59
23/53

:)

Is it bad gearing ratio for mtx4 ?

21/59
27/53

( these number actually mtx3 stock gearing )

The pulleys on the diff also changed, so you need to check what's right and what's nog on the mtx4...

Right, I can't say that I've tried to swapt engines but all the parts look very similar except the pinion-bell housing. If you are using 0.8 modules for both then it should be a close match between the 3 abd 4.

asw7576,

The internal ratio of MTX-3 is 2.53, for MTX-4 is 2.16.
If you use, 21/59 27/53, your first gear final will be (59/21)*2.16=6.07, your second will be (53/27)*2.16=4.24 which will probably be too tall for most track. The tallest ratio in first gear for MTX-4 is 18/58 which is 6.953 and second is 24/52 which is 4.675 which are still shorter than the stock gearing of MTX-3. :)

Thanks, mono !!

What is the effect of too tall gearing for engine ? Isn't that good considering top speed and less spin out of corner ?

Taller gearing means the engine will run at a higher rpm, so you get the idea.
You are right about the top speed and less spin out, but the gearing you provided is just too tall for most application other than speed run. :D

MTX 4 Assembly
 

Hi Guys,
Just assembling my MTX 4 now and I have a couple of questions:
1. Is anyone using Futaba servos? If so, what steering and throttle servo horns are you using?
2. Does anyone else notice how far the pivot ball retaining devices pretrude out from the rear hub carrier?
3. What offset tires are you guys using with standard pivot balls, driveshafts and 200mm track width? I heard the car requires 1 degree offset rims?

Thanks in advance, your help is much appreciated.
Cheers

Engine will run at higher RPM with taller gearing? How come? :confused:

I think its the other way... Shorter gearing means the engine needs less power to move the car using more RPM. Taller gearing means the engine will not spin so fast because its using all of his power to move the car. Think of what happens when you car gets stuck in first or second gear. If it gets stuck on second gear, means your engines's rpm will be much less meaning the fuel consumption will go down. If it gets stuck on the first gear, means the engine's rpm will be much higher meaning the fuel consumption will go up.