I'm not exactly sure what it is either. We used to say up to 20% drivetrain loss with an auto trans.
My L99 cranked off an amazing 315rwhp stock in July heat, seemed low to me but the car did go 13.1@106 stock and the 106mph seemed decent to me.
I did 368rwhp with exhaust, cai, tune, ud, went up to 112mph, so it would appear I make over 400 crank hp to propel a 4170 raceweight car down the track.
PROJECT HEAVY CHEVY
Camaro Now: Mods for the Masses Part I
| Part II
13.15@106 1.95 | 100% Stock
12.37@112 1.85 | + Kooks Headers/Cats + 20" 555R + CAI + BW TB + UDP + Tune
12.06@113 1.70 | + CD 3200 + 18" NT05R + RCR Intake + NE OTR + GPI Tune
11.84@113 1.59 | + 3.91s + Race Star 17x7 Fronts
__.__@___ 1.__ | + GPI VVT Cam + BW Ported Heads