Without getting away from ourselves, we are attempting to explain Scaling to the end user since not all of our templates explain this in detail. There are several ways experienced tuners like to do this, but effectively there is only one REAL way to accomplish proper Scaling to allow use of hardware larger than allowed by the ECU. Basically, it scares people when they're faced with having to do simple math for some reason. So.... read on..

When you add larger fuel injectors and/or MAF than the ECU is capable of calculating, you need to scale the tune file to ensure the ECU does not try to calculate above the maximum allowed.

Based on processor speed, the EEC-V (in the 96-98 Lincoln Mark VIII) has a maximum injector allowable size of 46.93 LBS/hr and MAF of 64 LBS/min. The EEC-IV (in the 93-95 Lincoln Mark VIII) has a maximum injector allowable size of 40.23 LBS/hr and MAF of 86 LBS/min before scaling is required. Done correctly, this will "trick" the ECU to think it is still running a MAF/Injector combo that doesn't exceed the max allowed in the coding.

In common entries for fuel injector changes you might see something like this:

Ford/Deka 60# Injector Base Values will be used as an example below.
AHISL, ALOSL, Pulsewidth and Breakpoint Scalars

0.0000299  Breakpoint
0.0166000  Hi (lbs/sec)
0.0178000  Low (lbs/sec)
0.0001290  MPW

The above cannot be used as a "plug in and go" with ECU's that the values will be more than allowed, or clipped by processor speed; so scaling the Dynamics can help get around it.

This is the scaling method we use to get around the ECU's max allowable calculation for Injectors and MAF:

Q: What if I'm not changing the MAF but only adding larger injectors than the normal scalars will allow?

A: If you're not changing the MAF out, but still need to Scale the tune for the new injectors; you can still compensate by scaling the stock MAF values. 

We like to MULTIPLY everything listed below to get our scaling values but it's up to you how you math it.

Get your Scaling Multiplier Like This

Enter your current or stock injector Hi Slope or max MAF Flow, then your new injector Hi Slope or max MAF Flow. Your Current Scaling Multiplier should be 1.00 in your stock or non-hardware limited tune file (see above). If you know your ACTUAL ECU's value of SARCHG or CID, enter it. If not, enter 1.00 to use Injector/MAF calculations only. NOTE --- You MUST use the same units of measurement for the areas marked with FLOW RATE.

New Scaling Multiplier or SARCHG to use is below. Remember to use the Scaling Multiplier in all areas needed like you see below the calculation.:

So below, we will get our scaling value by:

• Take Old Injector / New Injector = Scaling % multiplier - [EXAMPLE: 24 / 60 = .4  or  2.5 if you divide NEW / OLD]
• Take the KNOWN NEW injector value and change the entered NEW INJECTOR hi and low scalars against your value. - [EXAMPLE: 60 * .4 = 24 or 60  /  2.5 = 24]
• Old or Known New Injector Breakpoint gets addressed against your value.
• Recommended to set the Injector Pulsewidth value to your % in injector change while scaling it out against your value, or set it to 0.
• Take the STOCK MAF or MODIFIED MAF Transfer and change the entire Y Axis against your value. - [EXAMPLE: 46.77 LBS * .4 = 18.708  or  46.77 / 2.5 = 18.708 and so on]
• If you are changing the MAF as well, ensure you change all NEW 30 points against your value on the Y Axis. This is important because even the NEW KNOWN MAF Transfer has to be scaled and adjusted as well.
• Change the LBS/MASS and/or CID against your value.
• Same goes with the Manifold Volume. Change it against your value.
• Hit up FN040A or depending on XDF, Estimated Aircharge Vs. RPM and tackle the bottom 3 rows of the Y Axis with the value you got for starters. The rest of the Y Axis might need it too.
• Then Load w/ Failed MAF and Load w/ Failed MAF IMRC (if you have that) get the same treatment to ALL values in the table(s).

**IN ANY CASE, YOU LEAVE THE INJECTOR OFFSET VS. BATTERY VOLTS STOCK**

But Wait, I have a "Calibrated MAF" AND I am using the Scaling Method!!!

What if you have say a MAF that is "calibrated" for 42# injectors, and you want to put it on your Lincoln Mark VIII with 24# injectors but you have absolutely NO CLUE what the MAF Transfer is? Well, take 42 / 24 to get 1.75 then multiply the MAF Y axis by that value. Then take 24 / 42 and get .57. Go back to the MAF's Y axis and mutilply it AGAIN. You can do that with ANY MAF that exceed's the PROCESSOR SPEED. All you have to know is the Calibration to the injector for the meter. For instance, the 90mm Lightning MAF doesn't really exceed the processor speed in Ford form, dialing it in can get the fueling exactly where it should be by doing the above if you needed to.

The scaling method is perscribed for hardware that is known to exceed processor speed. Chances are, if you have a MAF Transfer to add, you should use it. Determine if the maximum flow will exceed the processor speed you have and go from there.

Some XDF's have a Clipped Scaling Percentage Scalar. 

That is the percentage of OEM that the completed scaling clipped away from the ECU controling AirMass and Fueling ineffectively. In short, this is the ECU processing you have gained by scaling the tune to allow it to control your added MAF and/or injectors that are larger than the ECU can calculate on it's own slope and transfers.

Negative number = % gained in AirMass and Fueling if your injectors and MAF require more values than the ECU processor can calculate without.

If you scaled as per instructions, you will see this number go NEGATIVE.

All of our Full Retail and Dealer XDF's use this same scaling technique. Lite XDF's do not have this access.

The Scaling Multiplier is a decimal placed value that acts as a Multiplier instead of a Divider. It is the same thing. All in all .40 = 2.5 if you reverse the two. See, a multiplier of 1.00 is a 100% OEM calculation point of AirMass and Fueling. A .40 or whatever you get is, tricking the ECU to think it is running a smaller engine by taking out 60% of the equation from the factors that determine AirMass and Fueling. Therefore allowing it to "think" outside of the box, and allow the mapping to correctly read and use actual values instead of clipping them.

Hope this makes sense..