AEM Water/Methanol Failsafe Device Evaluation
By Mike Kojima
We are very familiar with water and water/methanol injection; many years ago, we were one of the first to tune with modern water injection systems and took advantage of water's ability to inhibit detonation and provide charge cooling in forced induction engines. With water you can run more timing, more boost, leaner air fuel mixtures, a combination of all three or just use water to gain a measure of safety and to control engine temperatures for track use.
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| Our test car already had an AEM Water Methanol injection system installed. This is the version with the latest fast responding recirculating pump. The monitor can be adapted to work with most water injection systems. You just have to plumb in the flow meter, however it integratess fully with the warnings already built into the AEM system. Brian Kono of Afterhours Automotive fabricated this cool aluminum alloy bracket to mount the water tank, pump and filter so it would not intrude into our trunk space too much. |
There were some drawbacks to water systems. We have personally seen three cases where an engine was destroyed or severely damaged due to a malfunctioning water injection system. In one case a Hobbs pressure switch failed in the open circuit position allowing the injection pump to pump water at full capacity into the engine which hydrauliced a rod. In two other cases, clogged nozzles and high boost destroyed engines with detonation. In both cases plastic shavings from pushing water fittings together during assembly worked loose and blocked the small orifice water atomizer nozzles completely.
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| The AEM nozzle is cleanable and has a built in filter screen to resist clogging. The nozzle on our car is not the latest and greatest from AEM, the current AEM nozzle is improved with an integrated check valve and is smaller. This nozzle has the check valve in line a few inches back. |
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| The AEM nozzle comes with 3 different metering orifices for different flow rates, we used the largest one for our car. |
In one of our personal cars, calcification slowly blocked the nozzle over time rendering the system less effective. Fortunately we heard the detonation and investigated the root cause before the engine could be damaged. On our system, we had hooked a mechanical water pressure gauge to try to monitor the system but it was not sensitive enough to detect a partially blocked nozzle.
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| The is the standard AEM warning LED that flashes when the water injection is low on fluid or there is an error code stored in the control unit. We hooked the warning line out on the water injector controller to the auxiliary line in on the monitor so it will go into alarm mode for low fluid or for error codes as well. |
