Anthony’s FJ20 Gemini

Anthony’s FJ20 Gemini

We were contacted by Anthony shorty after he saw the performance benefits achieved with water injection in the CRE 1600. As he did not want to cut into his immaculate TX Gemini to fit a larger intercooler, he saw water meth injection as a great alternative to improve the performance of his non intercooled FJ20 turbo engine.

We assisted Anthony in the selecting and procuring the correct Aquamist system to suit his requirement, conducted the install and set up of the system and assisted with fine tuning and failsafe calibration.

After a few minor changes to the HFS4 system, the car was recently tuned. On the day of tuning, the ambient air temperature was around 18 degrees Celsius. The ambient air temp was around 18 degrees C and without the water meth injection activated, the car made 265 hp @ 16 psi boost. Intake air temps peaked at around 107 degrees C.

From there we turned on the Aquamist system and saw the IATs reduced to 45 degrees C at the same boost level. We then begun turning up the boost. At 25 psi, the IATs were beginning to reach 70 degrees C. At this stage, the decision was made to fit an extra 0.6 mm (260 cc) jet, roughly 400 mm from the compressor discharge, between the 1.0 and 1.2mm jets. Boost was then increased to 28 psi; with a corresponding power output of 345 hp. IATs peaked at 60 degrees C.

The water injection system utilises 1.2mm, 1.0mm, 0.6 mm and 0.5 mm jets and 180 psi pump pressure (set via the allen key screw in the pump head).

Maximum flow is calculated at round about 1500cc/min. It should be noted that no changes were made to the ignition timing. There may be an opportunity in the near future to experiment with ignition timing but it would require some addition charge air cooling to remain on the safe side.


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