Originally Posted by KLRCADI

Many G37's have 8000+ rpm tunes and I have not read of any issues yet. +500 rpm should not be that big of a variance for stock springs. The VHR's were designed for High RPM operation. Typically valve float is a precusor to spring failure, and I have never seen a dyno showing any high RPM float. I've seen Technosquare Dyno's running past 8100. They all seem to make power climbing right until 8K. I look forward to seeing this soon from tuners.