Hey everyone,

I wanted to post some of my thoughts/questions in order to get some questions and concerns on the board.

A little background: I have an USDM Impreza RS with and EJ2Z123G map. I have done headers, exhaust, intake ...the usual suspects.
I have been playing with the idea of a turbo kit for almost two years. I began with purchasing a PP6 and TD04, but after reading a bunch and investigating a little on OpenECU, I thought I would wait for the release of the RS definitions.
I began playing with the Enginuity software using some base definitions that allowed me to change fuel/timing about six months ago. Yes, I have had a definition that long...I thought it was too base to give it to the public.

I have been waiting for the latest release in order to allow me to put in the latencies and scaling for WRX injectors. I have that ability now, but I have been doing a lot more reading. That reading has me convinced that the RS ECU and accompanying sensors are just not going to work for the following reason:

1) Closed loop is not using what is obviously labeled Open Loop Fuel maps. It seems that calculations based on the limited range of the RS sensors could not possibly register boost.
2) Closed loop transition requirement changes would so vastly effect remaining parameter maps in the ECU that it would be extremely dangerous to manipulate these.
3) The stock ECU has limitations that are not desirable for a long haul progression towards big horsepower. (IE. fuel maps end at 6400 RPM and increased RPM would hit a wall)

The only thing I can see as a work around is to change all of the closed loop transition points in order to use open loop from 2500 RPM above in order to be able to set the AFRs without the ECU interfering. I know this is probably unrealistic unless you can tune the closed loop close to avoid long term corrections.

These are base thoughts, but the F/IC is looking a lot more attractive. I wish I would have kept the PP6 and purchased a fifth injector setup just to get started now....:diaf:

Like I said, this is to open the discussion. I would love to hear some tuning strategies with an RS ECU and some WRX injectors. I am not even sure you can enter the scaling parameters for a WRX MAP into this ROM. I noted a large difference in the WRX and RS ROMS in that the RS doesn't even show a Closed-Loop target fuel/air ratio table.


:confused:

You can rescale any 2d/3d axis, so that is not an issue.

Meaning you can change the scale of the RPM range?

In your opinion, can you safely modify the ECU to accept the use of a larger MAP?

In your opinion, can you safely modify the ECU to accept the use of a larger MAP?

Opinion has nothing to do with it, I have personally tuned a TurboXS 4 bar MAP on a STI ECU. So yes it can be done safely if you know what you are doing.

Isn't the 2005 2.5 MAF based though? From that maps I've seen they are, so why would you need to worry about the MAP? The stock MAF sensor is more than big enough for anything you will do with that engine.

You can change all the scales, RPMs can go higher, so can load. You can turn off the closed loop delays and use rpm/load to control closed loop, anywhere in the fuel map that is 14.7 AFR is closed loop.

I think you need to do a lot more research on the logic of the ECU. Alternatively, you have 2 very good tuners locally who could do it for you if you are still intimidated by it. Me and Dom.

Meaning you can change the scale of the RPM range?

Yes, what's what he means. Right now, your table runs from 0.2 to 1.3 g/rev in mostly 0.1 steps. You could change the column headers to run from, say, 0.2 to 4g/rev with a larger step interval.

Also, your 05 calculates off of RPM and load, not pressure. If you just set up the OL Fueling table with 14.7s where you want CL and fuel as you wish in OL, then set your CL->OL Delays to 0, the car will follow your fueling map.

Note that I have no data as to wither you'll need to change MAP sensors or settings in the ECU ROM to prevent the ECU from freaking out about positive pressure.

Note that I have no data as to wither you'll need to change MAP sensors or settings in the ECU ROM to prevent the ECU from freaking out about positive pressure.
He will most likely need to swap out MAP sensors if the '05 one is the same as the MAF based '99RS. My MAP sensor freaks out at 10psi and 50%+ throttle.

You have the capability to change the pressure sensor scaling in Enginuity if you went with an aftermarket sensor, which would allow you to correctly log boost (although, obviously, the ECU has no capability for boost control). What is not known, however, is how the ECU will respond to the higher pressures. MAP is used by the ECU quite a bit and I can't tell you exactly what effects that might have. Also, an RS-T tuning with the factory ECU with aftermarket injectors would be uncharted territory to begin with. But as master said, fueling is MAF based, and since you have the ability to change the injector latency and constant, then you shouldn't have any issue with fueling barring the unknown (at least as far as the ECU is concerned, meaning that everything mechanically is setup correctly - FPR, injectors, fuel pump).

Quite right. More research is needed. Mostly me.

It sounds like this is doable. I am interested in at least consulting my local tuners to get started.

I am going to build the kit, provide a larger aftermarket or WRX/STI MAP alternative. I think Sean at Rallitek mentioned they have a 3 bar they sell.

I think the injectors will be ok as I reviewed the settings versus the WRX this morning. Changing the offset and multiplier looks straight forward. I will probably do this first N/A to see what the effects are. Yes, I will definitely purchase a 255lph pump as well.

I will have more questions later, but I need to learn myself on the CL/OL transitions and calculations my paricular ECU is using.

I hope we can keep this ongoing as I am willing to guinea pig here. It will take me some time to get the kit together, but I hope we can end up with a sticky explaining the basics for the kit requirement based on using enginuity tuning. There shouldn't be many differences from normal kits.

CL/OL transition will not be something you need to worry about -> it is not that difficult to set up for an experienced tuner. If I were you, I would get the new injectors dialed in with the stock intake before adding the turbo. You also will need a wbo2.

Ah, I was wondering about that. I suppose the WBO2 can set up with the tables as well on the primary side before the cat. I am guessing the scaling and rich limits can be changed to match such an animal and then all logged through Enginuity.

No, the wbo2 should be placed downstream of the turbo (pre-cat), not as replacement for the front o2.

Tuning then. I need a unit capable of logging>?

LC-1 is compatible with the enginuity test release v774.

EXCELLENT! (Add Star Wars Evil Emperor voice).