For stage 1 the VEMS Genboard is a turbo fueler, and will only add fuel above atmospheric pressure. This is done through an extra set of injectors in a custom intake for this engine.
There are some things to simply accept when only having control over the additional fuel, the stock ECU is the problem. It seems to heavily rely on TPS as load which becomes a problem when you are not running WOT. The VE map is based on MAP in the VEMS Genboard, so only works with a fixed TPS position as the stock ECU calculates fuel pulsewidths based on TPS. Unpredictable air/fuel ratios occur when there is partial throttle and above atmospheric pressures.
We have to accept that the only way is to map the engine at WOT, and try to get the lower boost pressures to work adequately.
Injectors : 4x Bosch 192 cc/min, high-Z from BMW E30 318is