Had the 2013 Camaro on the dyno today. When the logged speedometer reading got to 158mph, that's where it stayed reading as the RPM's still climbed all the way to redline. Logged reading was normal up to 158 and the corresponding RPM, then returned to acting normal after the RPM's dropped enough to get below 158mph.
I'm not sure what to look for in HPTuners in the Speedo section. Compared to stock and nothing to see out of bound.
Strangely, it occurs at 6,000rpm. Coincidence?