ECU Load/Injector Calculation

[JoseCabra]

Hi,

I finished the instalation of the HFS-3 on my 2008 STi and was going to start tuning it.
I started to modify the AFR tables to lean out the fuel in the areas that the system would be spraying but it was mostly and educated guess.
I would like to know if anybody know how to calculate injected fuel from the load or other parameters. Or how to relate injector duty% to load. Or if you had any tips on leaning the AFR tables.

Thanks.

(Thanks Richard for your rreply to the wiring question; everything installed properly.)

[Howerton Engineering]

What fluid are you running?

Which jetting do you have installed?

What's your fuel injector size and # of cylinders?

[JoseCabra]

Hi,
thanks for the prompt response (btw I did buy my system from Howerton).

I'm currently running 50/50 water to denatured alcohol.
I installed the 0.8mm nozzle at TMIC before exit.
Stock 560 injectors 4 cylinders. I decided to try water injection because I live in Colombia and gasoline here is quite crappy, the best I can get without going to race fuel is 89 octane.
I set the HFS-3 controller at about 38% threshold and about 5-10% gain.

I'm using accesstuner Race to log and modify fueling tables.
Today I tried some modified maps I did basing myself off COBB Stage 1 for 93 Octane V104.
I modified the following areas of the fuel table 1.6 to 3.35 load and 2000 to 7600 rpms. I ran this leaner by about 6-8% in one map and 3-5% leaner in the other map.
By using data logging I found no knock and very little knock correction (it is very hard to get a good read on the engine with those crappy sample rates for logging).
Using the supplied virtual dyno I managed to log 234 whp and about 256 ftlb torque which doesnt' seem too bad considering I live at around 8000 ft above sea level.
The car felt better with the leaner map 6-8% leaner in areas mentioned above but it bogged down quite a bit in the upper areas of the rev range; above 5500 rpms.

I would really appreciate any help regarding my tuning of the system and what other steps you would suggest. Unfortunately there are no tuners or four wheel drive dynos here in Colombia.

At the moment I'm considering leaning the fuel a little bit more to around 10% from base stage 1 map. Reducing gain in the HSF-3 controller to a small negative value (around -10%).
After this I was going to mess with boost target table by increasing it around 5-8% in areas of high load where the system is injecting.
Finally I was going to mess with timing by adding around 1-2 degrees in the areas discussed.
When I go to lower elevations (around sea level) I was planning on using a 50/50 water methanol to increase octane and be safer.

My goal is to have a very safe car with good driveability offsetting the loses in atmospheric pressure.

[Howerton Engineering]

It looks like your water might be a bit much at high RPM. I think it will like it better with the gain a bit less, as you have planned.

Do you have a wideband on the car you can datalog as well? This is probably your best tool you will have along with knock readings. It's not impossible but is a bit tough doing it the way you are.

I'm sorry, but I don't know the particulars of your ECU, all I can offer is general help based AFR's, meth mixtures and system setup. I'm glad to help as much as possible, so if there is something I can help with please ask.