AEM Water/Methanol Failsafe Device Evaluation


We then fired up our laptop and downloaded AEM’s set up software from their website.  This is a cool way to ensure you have the latest versions of everything.  We plugged our laptop into the gauge’s USB port to do some data logging to set up our alarm flow limits.  We logged many pulls in 1st to 4th gear under many varying throttle positions and allowed the AEM software to log our fluid flow creating a scatter plot.  From the scatter plot we set our limit lines and adjusted the alarm delay and alarm reset parameters to 500 milliseconds and 4 seconds respectively.

AEM Water Methanol Injection monitor
We plugged our laptop into the gauge’s USB port and datalogged many runs through 1st to 4th gear at full and partial throttle to get this flow scatter diagram.  This helped us determine the water injection system’s normal range of operation.

Our EVO’s turbo is very responsive and develops boost very quickly so the injection range is wide.  Because of this we had to have a somewhat large alarm delay to avoid false triggering. As a result our plot didn’t look like any of the plots we saw in the instructions or on the AEM website.  We were worried about this so we had to give AEM’s tech support line a call but they assured us that this would be OK for this sort of car.

To test the system we first put a hose segment in line with the water nozzle with a small hole in it.  This would simulate a leak.  Sure enough the system immediately triggered an alarm.  BTW the alarm is pretty aggressive. For the alarm to stop, you either have to experience normal injection conditions for the amount of seconds that you set in the alarm reset parameter box or cycle the key.  Our beeper makes sure that you will notice that something is wrong and you will do something about it.

AEM Water Methanol Injection monitor
After several runs we were able to generate this data plot which allowed us to set upper and lower flow alarm limits.  Too much high flow indicates leaks caused by holes or blown lines.  Too little flow could be indicative of low fluid level, air in lines, failing pump, clogged nozzle, clogged filter or kinked lines.  For the set up software you can also set parameters for alarm delay which will make the alarm less sensitive to minor pressure fluctuations and the alarm reset time which controls how many seconds of normal operation it will take to reset the alarm and turn off the beeper.  You can also configure the gauge light intensity, color, flash rate and select flashing of the background, needle or both.  The gauge is very easy to set up.

To simulate a clogging nozzle or a dangerous flow restriction we used a hemostat to pinch off our test hose section and once again the alarm was triggered right away. With our testing we are pretty confident that the system will detect a problem! We left the USB cord in place so that we can also datalog the system from time to time if we feel like it or change the parameters if we do mods that change the engine’s boost characteristics.
We think that AEM’s injection system monitor is one of the best, most exciting products we have used in some time and while quite simple, is very effective.  The system can be made to work with other brands of water injection and you would be wise to use this if you tune around your system for maximum power.  If fact we think from our personal experience with water injection system failures that the AEM monitor is worth its weight in gold or at least engine parts.


AEM Electronics

Afterhours Automotive

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