I'd go 4s with the 5400 or 6800 for the fastest speed competition :). Actually, I could even make a 4s pack with the 2100HV cells I have laying around (for my 18t).
SH Z-Car, Custom Crawler, 8s Savage, 12s XTM XLB 1/7 buggy, 4wd 4-link rear/IFS Pro4 truck, Custom Hyper 10 Short Course, Belt-Drive Mammoth ST 1/8 truggy, 4s 17.5 MM Pro HPI Blitz
Well I sent it in today. I'll see what happens.
Can anyone think of a reason why they won't warranty it? I don't think I voided the warranty in any way.
Thanks.