A step to far? Need advice........

[Patrick]

I don't know how much different the buggy chassis is compared to the truggy, but I've raced with a guy that used 6s flightpower 4900's (140MM/44MM/63MM) lying on their side in his truggy, and had plenty of room to spare. Buggy body might still be a problem, I'm not sure.
He was using a 1700kv motor on 6s and it was over kill for our track (not so much in top end, but acceleration). An 8xl will definitely be more than you need in a buggy.

[Finnster]

Weight is also a consideration. While its prolly lighter than a 4s2P 8000 mah Maxamps pack some might use, its still rather heavy, esp on a buggy chassis. This sounds like its race oriented, so the extra weight may really throw you off.

How long are your mains you are looking to run? I would pick a battery that has just a bit more juice than you need (say, by 20%) as any extra capacity is extra weight you are carrying for no good reason other than to make the car sloppier.

EG. Some of the truggies I've seen burn about 7.0-7.5 Watt-hours/min in a race. IDK what a buggy needs, but somewhat less. So for a 10 min Truggy race you need a ~75 Wh battery. Now, just pick the voltage you want to run, and then divide to est the pack capacity needed. Ie, for a 6S pack you need a ~3.4 Ah battery. For a 4S a 5Ah batt. 8S, a 2.5Ah battery. Obviously then make sure the C rate is high enough for you power demands, but that too will scale with needed capacity so it shouldn't be a prob.

I would guess that batt would give you a solid 20min or more. If you don't need that much think about trading it, if you need it, great. If you need more, well... you may need a batt swap. g/l.