Aquamist IIC effect on Ignition Timing on Turbo Motor

I have a 1989 Volvo 740 Turbo, with a modified 2.3 8V turbo motor that currently runs 16 psi boost in daily driving. I installed an ERL Aquamist IIC, using the high speed valve that is spliced into an injector signal and thus follows the duty cycle of the injectors. The max flow at full duty cycle is around 300 cc/min. The fuel injectors are also about 300 cc/min, although I have a rising rate regulator that is currently tuned to provide closer to 370 cc/min. Water is thus maybe 17% of the 1780 cc injected. Maybe there is a better way to express that. My math is not great. I also have a Crane Hi6R ignition with TRC boost retard module. Without the water injection, I need to dial in an estimated (I have not measured it with a timing analyzer) 4 degrees of retard at this boost level. With the water injection, I need no retard.

I plan to install some temperature probes to measure pre and post intercooler temps to see whether I need the water injection to improve intercooler efficiency or whether it is beneficial in other ways. It seems to be beneficial; I just need to understand better why and how.

Philip Bradley

[Forum Admin]

Eric Fahlgren's site contains some information on intercooling here:

Water injection model results.

The turboICE paper attached in this thread here: http://www.turboice.net/forum/viewtopic.php?t=7 tries to cover all the ways injection benefits the entire system. As this board picks up activity I think you will have every question answered and then some.