i am planning on getting a new brushless sc10. how fast will it go if i keep everything stock but instead of a nickel metal battery i put in a 2s lipo?

Well, if you're looking at a 6 cell(7.2 volt) NiMh or a 2-cell(7.4V) LiPo, honestly there won't be enough of a difference to notice. The advantage of LiPos is not more speed, it's high capacity in a package that is considerably lighter(LiPo's typically weigh about 60-65% of a NiMh of the same capacity), & low electrical resistance such that you only need one LiPo pack & you can recharge it immediately after a run(whereas NiMh's need a little cooling down time first, about a couple of hours, so to do a lot of runs in a day, you'd need several NiMh packs). But speed will not be a significant difference in general....

I couldn't disagree more. While I can't tell you how fast your sc10 will go I can make you a 100% guarantee it will be faster, lighter and have considerably longer runtime. I first got into racing by borrowing a buddies slash with a 6 cell nimh battery and raced about 4 or 5 times like that and started getting pretty good. When I finally switched to a 2s lipo all of a sudden I couldn't keep the rear end from coming around due to all the extra power.

Totally disagree. You'll notice a difference immediately. I agree with jasons36, I had the same problem when I switched to lipo. They were so much lighter and had so much more punch I had trouble driving my car at first. They're way better than NiMh.

I agree with Jason.. you will see a difference in speed and especially runtime. My MERV on 6 cell Nimh's could barely lift the front wheels, on lipo (2s) it's a handful.

I also bought the SC10 - Brushless version. I've since upgraded the motor, but stock gearing with a 2s lipo will run around/under 30mph (maybe??). You'll eventually want to change out that Reedy 3300kv motor and ESC for something a little better for more speed. Start with a quality 2s lipo pack to get used to the truck and once your skills improve upgrade.

LiPo make car go zoom zoom fast

Just check your esc can handle it. since its brushless it will probably accept a 2s but might need an aftermarket esc if you want to run a 6s

Wow, then I guess NiMh's have really gone downhill in performance since I last used them. Of course, the only ones I ever used were the more expensive matched packs(near to what sponsored racers got, as close as I could get my hands on), & my own experience with them in the transition to LiPo was much smoother. I also have had a Novak Sentry for a few years(which can monitor actual battery voltage during a run & then play it back later on a PC), & my NiMh's actually began runs with MORE voltage than my Lipos, but the difference I saw was that the LiPo didn't drop off as much by the end of a run. And on track, I couldn't see ANY noticable difference in top end(& I did test runs with the same car, same ESC & motor, same setup, everything, only changed the battery), data from my Sentry saw NO change in top speed. Not saying you guys didn't feel a big difference, only relaying MY experience(which btw, spans over 2 decades, so I've pretty much seen it all). The only BIG difference is in weight, & that can account for some improvements in acceleration(& sometimes in unbalancing a vehicle, especially when you have that much less weight over the driven wheels)...