Compressor surge in pre-compressor injection

[cheekychimp]

John,

I have been thinking about this. I appreciate that in general it makes more sense for a water injection system to be activated by boost pressure because irrespective of where we are injecting we are trying to counteract the effects of heat which increase with boost.

In this particular application (pre turbo injection) however we are looking to extend the compressor map as it reaches it's limit. Now I understand that this is done by trying to get the compression away from isothermic to adiabatic which is temperature related BUT the compressor map usually reaches it's limits at a certain RPM as we reach WOT (wide open throttle).

I'm just wondering if an RPM activated or even possibly a MAF (airflow) activated injection point would keep the turbo in the sweet spot allowing us to extend the compressor range whilst avoiding surge.

Any thoughts!

Paul.