I have a New HKS 40mm Standard Wastegate controled by an Apexi AVC-R Boost Controller. Was at the dyno yesterday. Was tuning at .85 bar and boost control was great. However, when I was tuning for 1.5 bar ( on C-16 Race Gas ) the boost was spiking lower and higher amounts of boost with no control. Could the problem be a faulty wastegate? Thanks for any suggestions.

 

honda map sensors work up to 12 psi. .85 bar= close to 12.5 psi 1.5 bar = 22psi are you using OEM MAP sensor?

 

I'm using a SpeedPro Bank to Bank engine management unit.