After installing the Aquamist 4mm nozzles I ran through a series of duty cycle checks to determine the true flow rate through the nozzles, albeit into atmospheric pressure instead of manifold boost.

I found that after approximately 70% duty cycle there was very little increase in flow rate through the nozzles.

With the change in flow rate that the 4mm nozzles caused, capping the maximum flow rate around 375 mL/Min., I updated the Torq Tune Pump Duty Cycle table.

The new table values put the pump at up to 100% duty cycle, and do so at 17-19 psi, whereas with the pair of 0.7mm nozzles I was running the pump at a maximum duty cycle of 45% and recording more flow.

After utilizing a pair of 1mm Aquamist nozzles with my BorgWarner K03’s, a case of overkill that resulted in some misfiring due to an unnecessarily high volume of fluid being injected into the engine, I scaled back to a pair of Aquamist 0.7mm nozzles.

At the same time I was also beginning to utilize larger turbochargers, thus getting closer to a proper matching of components.

I’ve been operating with the 0.7mm nozzles for a while and through the ability of the Torq Tune software to enable me to tightly control the injection pump duty cycle I’ve been able to find a DC that has been producing good results.

I have been wondering if running the pump at a higher duty cycle, but with a smaller nozzle, would keep a similar flow rate at a higher system pressure.  The thought being that I may be able to obtain better atomization of the liquid with the quantity of liquid remaining the same.

To try and see if this is a valid idea I’ve obtained a pair of Aquamist nozzles in the 0.4mm size.

I’ll be assessing the flow rate through these nozzles versus the pump duty cycle, and then it will be onto the street to see how the Intake Air Temperatures change with smaller nozzles, hopefully at a similar flow rate to what I have been operating the 0.7mm nozzles at.