IT RUNS!!! - My 500whp build - Element motor and Moore Performance Twin Scroll Kit! by dexterous

6 minute(s) of a 312 minute read

I just finished a HUGE weekend working on the car! Here's my story and status:

As many of you know, I need to be able to switch back to the AccessPort/Stock ECU on demand so I came up with what I think is a pretty good idea. I purchased a number of "weather pack" connectors from one of my favorite vendors, Performance Plus Connection.

I then spliced my new weather pack connectors into a few of the wire looms on the car that connected either Hydra or Stock ECU specific sensors. I also installed three of these on the Hydra's adapter harness to make it easily removable. I no longer have any soldered wires holding he harness into the car which makes swapping ECUs about a five minute project. This pict is about half way through the job. I actually forgot to take a finished picture but you get the idea.

I started with the IAT sensor, which must be changed when switching between ECUs. All the Element Tuning base maps assume that the stock MAF with integrated IAT sensorare being used which means the stock piece is the preferred setup. While it sounds crazy, when using the Hydra, the stock MAF w/IAT sensor is supposed to be bolted into the fender NOT inside the intake or intercooler pipes. The idea is that the sensor will get an accurate sample of ambient air which is what the ECU really needs to know. I simply placed a weather pack connector on the end of the factory MAF loom and created an adapter harnesses so I could swap at will:

I created the stock MAF adapter by soldering wires on the end of the factory MAF plug to lengthen the 1.5 inch pieces I left when I cut the plug off:

Then I placed the weather pack pins and seals on the wires:

Here's an example of one of the pins. I use a torch on a very low flame setting to solder these instead of crimping them. I feel the soldering them is a much more reliable way of using the connectors.

Here's the finished product, stock MAF harness on one and and 5-Pin weather pack on the other:

I clipped this harness onto the maf which I have had bolted into my fender well for many years:

On the other hand, the AccessPort is setup to use a GM IAT sensor in the intercooler pipes. I made another harness with the same idea, weather pack on one end and GM IAT sensor plug on the other end. This harness had to be much longer as it needed to go near where the factory intercooler was located.

The Hydra also uses its own integrated MAP and Wideband O2 sensor. The MAP sensor is actually located INSIDE the ECU chassis instead of using a electric MAP sensor under the hood. Apparently heat has a very adverse effect on MAP sensors and the engineers thought that locating the MAP sensor inside the passenger compartment verses the engine bay would help.

I ran a long 3/16 hose from the intake manifold to the Hydra as well as the WB O2 wire from the down pipe to the Hydra.

I think this grommet is full now:

Once I had all the wiring done, I needed to load the Hydra 2.7 / 2005 STI base map that Phil sent me. I also needed to spend some time calibrating the WB02 and drive by wire systems. Here's the WB plugged in and warming up:

Calibrating the drive by wire system is similar to calibrating a joystick for a game console, you release the pedal (dont press it), hit a button and then press it all the way down and hit another button.

After getting the DBW and WB taken care of, I checked the status of the flex fuel sensor. As you can see here in one of the diagnostics outputs, there's currently 9.4% Ethanol in my fuel which makes sense (all fuel in PA is E10).

I also spent time working on programming outputs for the fuel system and boost control. Let me tell you that I REALLY missed this with the AccessPort. Being able to plug a wire in and program an output and then connecting a single wire for FULL functionality is amazing. With the AP I spent months designing complicated electronics to take the place of the Hydra which really sucked. i wont have all my automated gadgets running on the stock ECU any more but its not that big of a deal since thats just for troubleshooting, future emissions testing (if it ever happens), etc.

The good news is that my Hydra 2.7 is installed, programmed and ready to go. Now all I need to do is take the car down to Phil and have him pick up where I left off.