bigtee01

iTrader: (4)

I see some people are removing every other tooth on front a rear diffs. I been trying ton find some info on this to see how many people is doing this mod and what's the pros and cons.

glennhl

iTrader: (16)

Taking every other tooth off a diff seems like a strange way to free up the drivetrain. The diff gears only move relative to each other a little bit in a corner. Maybe they are doing this to free up the diff, but not the drivetrain, but what I've read is they get rid of every other tooth and then go to thicker diff fluid, so that's just back to where you start.

Can someone give me a better explanation of why people are doing this?

SteveM

iTrader: (165)

When I raced the HPI Micro RS4 in box stock configuration years ago, the stock single drive belt was a bit too tight. In order to loosen things a bit and to maximize speed, I sliced off every other knub on the belt. The benefits included a lighter drive belt that was also more flexible and produced less drag as it went around the front and rear pulleys. My car was slight faster as a result.

kingofcool999

iTrader: (7)

I could see you doing that successfully on a belt drive, but not on a gear drive.

In the past I've used abrasive paste to polish gears. Start with clean gears, put the paste on the teeth, then run them under no load. The paste will polish the gear teeth. Disassemble, clean, reassemble. Should be silky smooth.

I used to use tartar control toothpaste, but I've been told that it doesn't contain abrasives anymore.

mooby64

iTrader: (3)

If you are running 17.5 or slower motors, try removing 2 of the internal spider gears. Less mass and less friction.

bigtee01

iTrader: (4)

I was talking on the pulley not the internal gears

gigaplex

iTrader: (2)

I can't see how that would help other than the negligible mass reduction. Cutting teeth on the belt would be more effective instead as most of the resistance is in the belt flex characteristics. I'd still not bother doing so unless you have a spare belt. And definitely not for mod motors.

glennhl

iTrader: (16)

OK, thanks. I can see that might reduce friction a little, but I'm not trying it.

bertrandsv87

iTrader: (2)

If you want to really take the mass out, then change all the drivetrain steel parts to custom made aluminum, and two plastic spider gears instead... Wear will increase, but laptimes will decrease...
Also, a lower friction belt is a better choice than potentially ruining your current belt...

Antimullet

iTrader: (65)

Soak all your bearings in wd40 or similar overnight to dissolve the grease, dry them with motor spray, lightly oil with bearing oil or auto transmission fluid.

That will free it up quite a bit. You just have to monitor and re-oil a little more often. If you're racing though it's worth it.

GuyIsDamGood

To free - up the drivetrain on a Shaft Drive Car you should remove a shim (or install a thinner shim) along the center shaft or on a axle.

Trez83

iTrader: (8)

Do you have to disassemble the bearings to re-oil them? Aren't bearings sealed? How do you get around the seal?

Antimullet

iTrader: (65)

nah the oil will work its way into the bearing. I just put a few drops on each one and let them sit a few minutes.

MikeR

iTrader: (15)

bearings are not sealed- just shielded.

niznai

If you do that, you won't need to oil the bearings afterwards, just let the WD40 drain out so they don't leak and create a mess everywhere and wipe them clean outside (no cleaning spray). It won't leak out completely. Spin in your hand to fling the excess oil out and when they spin freely with no leak, there's only enough oil left inside. Wipe clean the outside again, and you're ready to go.