fazm83, Sorry for being so dim but bear with me. With an open (regular) differential, BOTH wheels are being powered ... not just one wheel. Provided, of course, that one wheel isn't slipping. As long as both wheels have the same amount of traction (99% of the time), the reg diff will act exactly the same as a LSD (i.e 50% power to left wheel, 50% power to right wheel). Only if one wheel starts slipping (due to less traction than the other) will the LSD give you better traction/acceleration. But, if there is *any* wheelspin at all, you've just blown the "best" possible run. Again, to get the best times possible, you must have NO wheelspin. And, if you do have no wheelspin, a reg diff acts exactly the same as a LSD (50% left, 50% right). I get the feeling you think that a regular differential only sends power to one wheel.