New HFS4 owner with initial setup questions

[FI_Rubicon]

Some install pics of my work so far....

[Richard L]

This is an incredibly neat install. Most impressed. Look forward to more pics.

[FI_Rubicon]

Originally Posted by Richard L

This is an incredibly neat install. Most impressed. Look forward to more pics.

The system is up and running. I am still running pure water and still doing some initial tweaks.

Here are the wire connections under the hood. I Posi-Taps to make the connections.

The easiest injector to tap into was is the passenger side front cylinder (#1?). The correct connections are as follows:

The green wire in the Aquamist ECU harness connects to the negative side injector pulse. It is the brown/yellow wire in this picture. The red wire from the Aquamist ECU harness connects to the other injector wire, brown/white.



For the MAP sensor signal, I tapped into the MAP sensor extension harness that Edelbrock provides with the supercharger kit. This harness is wired incorrectly from Edelbrock and you either need to switch the wires or mash the connector in backwards (Edelbrock supposedly suggests this). The miswired connector is the one that plugs into the factory harness. The side that plugs into the MAP sensor is correct. The wire that you want to tap into is the Purple wire in the OEM harness. The Edelbrock harness has the yellow and purple wires crossed. The ground in the center is correct. The wire in the Edelbrock harness is yellow.



I tied the HFS4's AUX input into the IAT sensor. The Edelbrock kit relocated the IAT sensor from in front of the throttle body to under the supercharger and intercooler manifolds, just before the intake valve. The kit included an extension harness. I just tapped into the extension harness. There are two wires. The blue wire is the +5VDC source. The blue with black wire is the signal from the thermistor.



I forgot to snap a picture of the wire tap for the lighting circuit but I used a passenger side tail light circuit (US model). It passes along the passenger side rocker and up the kick panel into the engine bay. The harness passes near the glove box and I tapped the white wire with an orange trance (after discovering it electrically at the taillight).

I also have it wired to the Diablosport Trinity AUX 2 input and it seems to be working, though I will need to calibrate it. Now I am pulling in *two* aux inputs for data logging. I will be able to log the flow rate of the WMI as well. It is not an ideal match because the Diablosport Trinuty expects a 0-5v signal versus a "conditioned 0.5-4.5v" signal.

[Richard L]

I will address your questions. First, congratulations on such a beautiful install.

Triggering option of the system:
1. IDC .......... Activation by fuel duty cycle (default)
2. MPS ........... Activation by boost pressure
3. P+I ............ Activation by the "average" of the above two **

** Average is weighted on the P/I-R trimmer settings (Pressure/IDC Ratio)

There is no strict rules what is best suited for your car. It depends on the spool up speed of the super/turbo charger.

Some old school tuners will swear by system should trigger and flow by boost pressure. It makes sensor if you have a belt driven supercharger, where boost is quiet close to true engine load. But when it comes to a turbocharged engine, this rule can no longer applied reliably.

Without RPM reference, turbo Boost pressure has little relevant to true engine load. It is especially true with the modern engine with electronic throttle and cam angle. High boost pressure does not represent more air going into the engine if the throttle is half shut.

I think you should use IDC trigger and use the P/I-R trimmer to find tune your meth/water flow.


For the soft gauge implementation, you can use the equation:

Vg = (Va-0.5)x 1.25
Vg = soft gauge, Va (aquamist)

[FI_Rubicon]

Originally Posted by Richard L

I will address your questions. First, congratulations on such a beautiful install.

I think you should use IDC trigger and use the P/I-R trimmer to find tune your meth/water flow.

Here is a little spray test video that I made...

https://www.youtube.com/watch?v=5s7FxRkqhwA

Thank you. After playing with it, it seems to operate more smoothly setting the trigger to IDC versus P-I but I need play around with it more.

I do have a belt driven SC.

If I have the jumper set on P-I and twiddle the THRESH gain, does it affect the trigger point for P as well or just IDC?

[Richard L]

What is "THRES gain"?

[FI_Rubicon]

Originally Posted by Richard L

What is "THRES gain"?

That's American for "THRESH trimmer."

[Richard L]

THRES will only be affected by twiddling the PI-R trimmer in P+I trigger mode