Longevity
 

If its set correctly you should get a good bit of running out of it. Ive been running my last rebuild for about a month and a half i race every week sometimes twice.:)

I have a couple of B-Fast diffs in stock for the Mad Rat at the moment, looking to retail them at £35 including postage for a complete diff including diff and thrust grease,
A complete diff comes with diff plates, shims, carbide diff balls, thrust plates and thrust balls and instructions,

for more information click below

http://www.bfastrc.com/tqracing.html

please send PM, not posted up on website yet.

I received my bfast diff kit this morning, build it this afternoon, and wow ! Very smooth !!!

Big test this sunday during a race.

Nice, they are definitely the first after market item to have on these cars !:). Let us know if you set your best lap time

Err wouldn't be cheaper to sand the rings down your self? I use 600 wet and dry on a flat surface and a bit of elbow grease and sand the ring by truning them in a large arc, inspect to see where there are unsanded areas those are your low spots. sand until whole ring has and even grained finish. Do both sides the ring are pressed from sheet steel they are not flat. I would then sand them down with 1200 grit wet and dry until you get a mirror like finish. do not polish! the texture surface allow the balls to grip the plates. when you rebuild the diff sand as per the previous procedure the grooves out and rebuild. it take less time to sand the groove out than prep new rings! I do this for all my diffs and use ceramic balls, end up with very smooth diffs that are low maitenace as well, cause they wear is even across the ring it less likely to go notchy, and you don't need to set the diff as tight to eliminate slip. see this link

I've done it on my 2 stock diff, but they're now dead, both rings and balls.
You're right, it's cheaper.

But as I don't have anymore good part of the stock diff, I decide to test the B-Fast one.
If the BFast diff is more durable than the stock one, it became cheaper to buy the BFast one, because it is better also.