Ford 42lb Injector Writeup – PDF

Injector Offset Tables – ZIP

RedHardSupra’s Injector Spreadsheet

Ford Racing M-9593-F302 Calibration Summary – PDF

Ford Racing 42lb/hr Injector Tuning – 50.5

I put 50.5 in the title because I’m not trying to school anyone here with some radical Injector 101 junk, but rather share my experience tuning the injectors.  I hope that someone might gain some sort of knowledge by reading this, and if you don’t that’s fine too I guess.

First off, here’s a list of mods that were done to the truck when I first got my hands on it.

6.0 LQ9, Magic Stick V.3 (MS3) Camshaft 237/242 .603/.609 112 LSA, Pacesetter headers, custom ORY, Custom 4” CAI, 4L80E, Ford 42 injectors, and Circle D 3800 full race billet converter.

I figured idle surge would be a pain with this cam, but it really wasn’t as bad as I was expecting considering the cam specs.  One of the first things I did was to download the fuel injector spreadsheet on Marcin’s website to see whereabouts the injector flowrate vs. kpa table should be.  One thing that most people overlook when changing to Ford injectors is that they’re rated at a different rail pressure than LS1 injectors are.  Ford vehicles run at 39.15psi while LS1-type fuel systems are running at 58psi at the rail.  Just simply plug in the values into Marcin’s injector spreadsheet and there you have your IFR (injector flow rate) table for HPTuners.  The spreadsheet also has a page that’s tailored to EFILive.  Basically all you need to do is copy the injector flow (lb/hr) table and paste it into HPTuners under engine>fuel control>general>injector control>Flow Rate vs. KPA

Once this is done your tune is now programmed for the correct flowrate of the injectors, but the injector offset and pulse-width values still need to be modified since Ford uses different theories/calculations for designing their injectors.

Probably one of the most important documents needed for this is the spec sheet that I found for the part number provided with these injectors.  It doesn’t come with the injectors nor was it easy to find on the internet.  Originally when I searched for the calibration sheet the injectors were still considered a “valid” part number for the Ford Racing Parts website, but now apparently it’s “no longer available.”  If you follow the link below you can see this information, and if you scroll down enough you can see a link to the M-9593-F302 Calibration Summary.

http://www.fordracingparts.com/parts/part_details.asp?PartKeyField=4814

The calibration sheet shows many vital pieces of information about the injectors, but in a rather unfamiliar format compared to what we’re used to seeing in HPTuners.  If you take a look at the following image you can see that even though the Offset vs. Volts vs. KPA VAC references manifold pressure it doesn’t change much horizontally.

Horizontally the values change very little and since  the Ford calibration are a single column I just copy the values for each voltage across the entire KPA range.  I’ll use 12 volts for the first example.  At 12v the voltage offset (ms) is 0.919, so we’re going to enter that value across the entire table for 12 volts and it should look like this when you’re done.

We’ll do the same for the offset at 13 volts and it should look like this.

Use the same procedure for all of the voltage levels found in the ford calibration spreadsheet.  You won’t use every voltage setting from their spreadsheet, so don’t worry.  Thanks to the guys at HPTuners there’s a vertical “smoothing” function built into all the tables.  What we’re going to do is select the range from 12-13 volts vertically and it should look like this when selected.

Notice where the “Smooth Between Vertical Bounds” button is at the top of the table.  Click this button until you don’t see any of the values changing anymore between the two voltage ranges selected.  When you’re done it should look like this.

The values between 12 and 13 volts were smoothed out to be exactly between the offset of the respected voltage range.  Repeat this step for the remaining voltages.  Some voltage ranges might be 2 volts apart which would be approximately 4 cells, but don’t be worried.  Just smooth the values between the vertical bounds and it should be as close as we can get them without Ford providing offsets in all 1 volt increments.

When you’re done you should have a table that looks like this.

There’s one more step needed to “finish” the offset table.  On the right side of the calibration summary you’ll notice there’s a FNPW_OFFCOMP table that basically shows the multiplier for the offset table according to different fuel pressures.  Since we’re between 54.95 and 60.05psi I took the average of the two multipliers which came out to be 1.1029.  Now all we have left to do is multiply the whole Offset vs. Volts vs. KPA VAC table by the multiplier of 1.1029 to get our final offset values.  I’ve included the .txt file for my final offset values so you can just load the table directly into HPTuners.  Here’s what the table looks like now after we used the multiplier.

Now that we’re done with the offset table we can move onto the rest of the calibration summary.  The last thing left to do is the MINPW value.  The calibration sheet doesn’t specify whether or not you’re supposed to use a multiplier on the MINPW value, but it does note that the value is referenced to a fuel pressure of 39.15psi.  We can use the listed value of 1.130ms which actually worked just fine, but some people might choose to use the multiplier we calculated earlier given that it’s referenced to a lower fuel pressure.  If we do that our MINPW value would end up being 1.246ms, and this goes into the Minimum Injector Pulsewidth table in HPTuners.

That pretty much wraps up everything for tuning Ford Racing 42lb injectors.  The next steps would be to retune any VE and MAF tables as your AFR will most definitely change once you install these injectors.

Any questions or comments please feel free to email (tunedbyjake@gmail.com) or comment on the website at www.tunedbyjake.com

As you can see from the gauge I hit about 124* during the log.  That’s HOT!  Looking at a stock tune, you can see that at 124* IAT the computer will pull about 6 degrees of timing on top of whatever Torque Management is taking out.

After seeing this repeatedly I tried to think of a way to keep my IAT’s down so I wouldn’t lose too much power off the line.  Up top it was always fine since when you’re moving at a decent speed the temperatures under the hood are a lot lower, but after idling in a parking lot or just cruising around town in traffic the temperature goes way up.  I finally remembered seeing fiberglass header wrap on the shelf at Oreilly’s and figured that might help insulate the intake a little bit.  Before that I had dreamed up some pretty crazy ideas to chill the intake including liquid CO2 haha.  Installing the fiberglass wrap was pretty straightforward and easy especially if you buy the stainless steel ties that are offered by the same company.  Here’s what it looked like before:

And after:

After I got everything reassembled I took the truck for a spin and logged the IAT’s again and saw a difference of 20* pretty much across the board.  One of the better mods for the money that I’ve done honestly.