4s 8000 lipo what brand?

[superek4]

ok, i hv previous record of my last race i charged my batts n it ended at 3380, i estimated i hv ran for 20-21mins so izzit 3380/21mins? =161mah per min?

i had 12pinion at 50spur with 1600kv motor so what batts i need to do 30min?

izzit 161mah/per min x 30mins?= 4830mah i need to run a 30min race?

if i am going to run at 13pinion do i need more mah?