Greetings -

I've got a set of modded stock injectors that were flow tested at 43.5 psi and flowed 835-840 cc/min. I'm running open loop fueling and want to set the Injector flow parameter appropriately before I start tuning the fuel map. It's a 2.0L WRX with all the supporting mods.

1) Since 43.5 is the stock fuel pressure, is that what the 565cc STi injectors and 420cc stock injectors were rated at? (i.e., should I enter a value of 820-830 as the injector flow due to the results above). Obviously at 30psi of fuel pressure the injectors flow less (maybe 740?).

2) This parameter applies an offset to the 0% fuel column, but does it apply across the entire fuel map? 10-100% columns?

I searched a bit and read a bunch about the injector scaling, but can anyone answer these quick questions? TXS? Anyone...

Thanks in advance!

:)

The OLF setting in the UTEC is an overall setting that effects all fueling points. If you set it to 830/420, it should start right up, unless that correction (almost 50%) is too large... I don't know how WRX's handle their fueling that low in the MAF voltage range. Might just throw a CEL complaining it's out of range, but it shouldn't just fail and not work.

I highly suggest you get the car tuned by a pro, though... that is a lot of correction and it very likely will need tweaking at individual points to run smoothly/correctly.

You will also need to tweak some of the 0% fuel columns to get the fuel trims to be happy.

I've got an OBDII scanner that can read the fuel trims coming in the mail, so I'll definately check and adjust the 0% column. The 0% column fuel adjustments ONLY adjust that column correct (i.e., they are NOT like the injector scaling which applies across the board)?

I have a tuned stage 4 with a great set of fuel maps, but I'm swapping turbos and injectors so all bets are off. I'll learn alot though... :)

0% is just for the 0% column.

I've got an OBDII scanner that can read the fuel trims coming in the mail, so I'll definately check and adjust the 0% column. The 0% column fuel adjustments ONLY adjust that column correct (i.e., they are NOT like the injector scaling which applies across the board)?

I have a tuned stage 4 with a great set of fuel maps, but I'm swapping turbos and injectors so all bets are off. I'll learn alot though... :)


Using the stage four map dictates that you use the STI injector size, NOT the wrx injector size in the OLF scale, since the map was originated using the STI injectors,:ie; 820/565. That will give your UTEC a smaller correction factor and make tweaking a little easier but you'll still have to modify the 0% columns.

Using the stage four map dictates that you use the STI injector size, NOT the wrx injector size in the OLF scale, since the map was originated using the STI injectors,:ie; 820/565. :huh:
That makes no sense.

Sure, he can use the Stage 4 map for timing, but when it comes to the fuel map, all bets are off.

The best bet is zero out the fuel map, scale the injectors as needed for to get the fuel trims close to zero, then adjust the scaling numbers up or down equally to get the WOT fueling close to where he wants it to be. Once that is done, start tweaking the fuel map.