Losi Smart Diff
 

Anyone running the smart diffs? From what I read the seem like they would help a brushless setup.. Anyone have experience with them?

from what I have heard it eliminates having to deceide what viscosity fliud to run in your diff, it acts like limited slip differential in a full size car and it uses grease. depending on what is needed more traction or less it detects this and applies. It is a drop in upgrade, you might want to open it up and check the amount of grease to see if they have enough before installing. Replacing the front diff makes the biggest improvement than the center, there is no need to replace the rear. The losi is a similar design to the Fiorini for a lot less money the Fiorinis go for about $250 a piece

And Xray has exact same diff, called Active Diff.

I wonder how it acts on (motor) braking....

I've been playing around with the Smart Diff in my E-8ight. I bought the center version because that's what the Losi pros recommend to start with. With it I noticed an improvement in both acceleration and on power turning in loose conditions. The car tracks better in the turns and the rear no longer trys to swing around. This would work very well on most larger 1/8 style tracks.

For where I drive at this time of year the SD in the center was not completely what I was looking for, so I swaped it into the front. You have to change the outdrives and spur gear to do this. The areas I drive at this time of the year are a good sized backyard track and a nice clay indoor track. Both are set up with tight turns for 1/10 vehicles. With the SD in the front the 8ight turns like mad, and pulls the front end through turns on power better than in the center. The rear of the car is a bit loose, but this helps to swing it through the tight turns. And, one other bonus is the car is incredible through the whoops at are backyard track. The front pulls so hard that it will just skim across them. In the stock setup I had to go much slower.

As for braking the SD brakes just like a regular diff, but the brakes do seem a bit stronger.

I was hoping for something like a one-way in the front, so all braking power goes into the rear. I find with motor brakes, the front end tends to plow a bit more than I like, was hoping the SD may help this but I didn't quite see how it could.

A SD works something like 1,000 wt oil off power and 10,000 weight oil on power. When you hit the brakes it does not work like a one-way.

how was the amount of grease in the diff before you installed

There wasn't much IMO, but I'm not sure how much there should be. It seemed the ramp surfaces were greased, but the gears were pretty dry.

When I first got my Smart Diff I opened it up to check the grease, this is what it looked like. So far I really like it, I am running it in the center and I do notice improved acceleration. The spider gears are much smaller and there are ramps that clamp down on the spiders so I was concerned about wear, but after 5 or 6 packs the gears look fine.

http://i142.photobucket.com/albums/r...3/DSC05434.jpg

Could anyone get some measurements?
Im wondering, if it will fit my Hyper... I have heard rumor, that its too big to fit Hyper housings...

Yours has a lot more grease in it than mine did. I did add some, but still not as much as you have.

An active diff only needs enough grease to keep all of the gears lubricated. Any more is just a waste.

I think the smart diff in the center (and front) would be beneficial. If the diff acts like 10k on acceleration, this is about right on a looser track. If it acts like 1k on braking, then it should diff out and apply "mostly" rear braking action(though not instantly).

Braking forces from the motor cause the smart diff to act just like on power, so it does not seperate the front from the rear when braking. It's only off power that the diff acts like it is very low oil weight.

Now that I have my SD in the front of the 8ight I'd really like to try a Slipperential. Mike is there an updated ETA?