Like the subject said, what's a one-way differential and what does it do? I've been hearing they make drifting way easier, is there truth to that? Can I get one for a HPI Sport 2?

Though I'm new to drifting and don't quite know how this fits in to making drifts easier, I would guess a "one way diff" is a locked out differential? In the monster truck world and with rock crawling you can put a spool in your diff in place of the spiders to lock the output shafts together to the diff, giving you 100% power to each wheel. This way when one wheel starts spinning during your drift, the other wheel will stay the same speed. Usually this is considered to make the car handle worse and more difficult to turn but the inverse may be true with drifting cars.

Now, anyone care to explain everything I missed in above paragraph?

The above post describes the use of a locked differential, which does exactly as you described. However, a one-way differential is a differential for the front of the car which allows the front wheels to free-wheel under de-acceleration or braking conditions. This makes the car act like a 4wd car under acceleration, but a 2wd car when you let off the throttle or hit the brake. It's a lot easier to get the car to break traction or control the slide with a one-way. Hope that helped!

By the way, this is my first post on rcuniverse and hopefully not the last! [8D]

So does anyone know if there are any aftermarket one-ways for the HPI Sport 2? I've looked and cant seem to find any. HPI's site doesn't even have them.

Thanks for the explanation Scott S. That sounds like a must have?

Ah of course!

I didn't realize I have a old kit with one of these types of differentials already installed. Maybe I should bring it back to life...

When I used to race my RS4 Pro back in the day, I used a one-way pulley. It works the exact same way a diff does, but lets the front belt also spin independently. I'm not sure if it's still available, but I know it would work with your sport 2.

I have a one way diff in the front of my Sport 2 and like the other people have said it only allows the back brakes to do the braking. Sometimes when im in a drift and i want more sideways action i hit the brakes and because only rh back brakes are doing the braking its like applying the hand brake in a real car thus the back of the car swings round more... Its a little tricky to get the hang of it but it works pretty well!!!