It means that the 335i can push 422.5hp worth of air and 24psi midrange and 18psi(compressor outlet peaks) at peak power while still staying in the compressor map(before choking the turbos) ie anything over 380whp is pushing the turbos beyond factory(mitsu) tested limits
The upcoming Helix direct bolt on turbos can push similar pressures but the power output potential is 570HP
we'll get some pics up next week when Ralph and Eric return from Minis on the Dragon
