When I was out in California a couple weeks ago, Truhe and I were doing a lot of testing at WCRC, which consisted of running the short 3800 60c xcelorin battery. Truhe and I both ran one battery with normal 5000 pack and then swithced to the short 3800 battery. Over 5 minutes our average laps were 2-3 tenths faster. The car definently jumped and landed even better than it already does, along with improving the balance of the car. I was very impressed with the improvement in the car by just putting the short battery in! Also, like Frank posted I went 17 minutes on that battery at WCRC and still could have gone a few more minutes, so run time is definently not an issue.