Ford 2019 Bullit Speed Density Clarification (MAF settings)

[evolmotorsprt]

I about to start working on a 2019 Bullit with an Edelbrock 2650. I plan to make my initial changes, dial in the MAF, and then start figuring out the speed density.

I have the HP pro features, a stand alone MAP, and understand the process for tuning SD, but I haven't seen clarification on failing the MAF, or if I even need to. Should I treat this like a GM and put the sensor out of range in the tune file, unplug the sensor, etc?

[Auto-Hentzschel]

the Bullitt is a bitch! I had spend weeks on the dyno to get the EForce running smooth!
BTW you need the Tuner kit plus Throttle body and SC pulley.

[evolmotorsprt]

I figured it would be. We were able to talk to Edelbrock and get the 5.0 GT stage 2 Coyote tune as a starting point. We also have all of the extra parts for the Bullit. On the mustangs I've done in the past, I haven't worried too much about the speed density side, and they've driven well. I know because of the PD blower and differences between the Bullit and regular GT that I'm going to spend some time doing SD.

I'd still like to know how people are handling the MAF

[Grim5.0]

Something to consider, the bullitts only different from the gt via TB/intake mani/intake. If you put a blower kit on with all those components replaced, any generic gt tune setup for that blower should be a great starting point.

[murfie]

Cars run completely off the MAF or completely off a MAP sensor, depending on what they have, the non existent sensor is inferred through the SD model. No failing MAF to correct anything as there's no backup sensor to determine airmass from. You added an external sensor to correct the inferred MAP value.

Y= A x^2 + B x + C

Y is inferred map

x is load, more specifically cylinder airmass derived from MAF value and RPM. Load comes from current cylinder airmass / Maximum cylinder airmass. cylinder displacement of .00168 is the maximum cylinder airmass in pounds. using pounds per minute and revolutions per minute, you can get pounds per revolution. You divided that by 4 as there are 4 intakes per revolution in a V8 and thats the cylinder airmass in pounds. This is the value put into the equation above to solve for Y and get a MAP value. You can use this until you hit the MAF lb/min PID limit at 86.68, then you need to use the airload value to get the MAF values that are higher than that since the air load doesnt have the same PID bit limit.

So using the HPT calculator they want you to log air load(X values) and an external MAP sensor(actual Y values), and populate a new relationship in their calculator and calculate new coefficients. IMHO Its not very good at this. doing it in an excel sheet and using linest or the equivalent 2nd order polynomial function works better to come up with your own coefficients. If you hate excel there are websites you can populate with X and Y values per RPM, that will also do it for you. Populating the coefficients then using the calculator to check they work is a good thing and the calculator works very good for that. The other option is to just guess at coefficients and look at the changes populated in the calculator until it matches what you logged. I don't recommend that as it can be time consuming.

[evolmotorsprt]

Cars run completely off the MAF or completely off a MAP sensor, depending on what they have, the non existent sensor is inferred through the SD model. No failing MAF to correct anything as there's no backup sensor to determine airmass from. You added an external sensor to correct the inferred MAP value.

Y= A x^2 + B x + C

Y is inferred map

x is load, more specifically cylinder airmass derived from MAF value and RPM. Load comes from current cylinder airmass / Maximum cylinder airmass. cylinder displacement of .00168 is the maximum cylinder airmass in pounds. using pounds per minute and revolutions per minute, you can get pounds per revolution. You divided that by 4 as there are 4 intakes per revolution in a V8 and thats the cylinder airmass in pounds. This is the value put into the equation above to solve for Y and get a MAP value. You can use this until you hit the MAF lb/min PID limit at 86.68, then you need to use the airload value to get the MAF values that are higher than that since the air load doesnt have the same PID bit limit.

So using the HPT calculator they want you to log air load(X values) and an external MAP sensor(actual Y values), and populate a new relationship in their calculator and calculate new coefficients. IMHO Its not very good at this. doing it in an excel sheet and using linest or the equivalent 2nd order polynomial function works better to come up with your own coefficients. If you hate excel there are websites you can populate with X and Y values per RPM, that will also do it for you. Populating the coefficients then using the calculator to check they work is a good thing and the calculator works very good for that. The other option is to just guess at coefficients and look at the changes populated in the calculator until it matches what you logged. I don't recommend that as it can be time consuming.

Dude you rock! I think that?s about the most to the point explanation I?ve heard. I?m definitely not afraid of Excel, So I will do my work there and then test my values in the calculator. Thanks again!