The problem is the the piggy backs cannot adjust timing or rev limit. It basically adds boost and fuel. The stock programmed boost/timing curve drops off substantially after 7900. There is no reason for this other than that is how the factory programmed it. The 1100T engine is much happier at 8100 rpms vs 7800. What I mean by this is detonation is less likely at 8100-8500 vs 7800. The rpms where detonation is most prevalent is 7500 to 7800. Unfortunately this is where the stock boost timing curv