How air is being measured?
08-10-2011, 03:02 PM
#1
How air is being measured?
How is fuel calculated when boost is measured?
For regular multi port fuel injection it has a Fuel Pressure regulator that bumps fuel pressure 1:1.
I've read DI does not use a fuel pressure regulator so how does it know how much to throw
For regular multi port fuel injection it has a Fuel Pressure regulator that bumps fuel pressure 1:1.
I've read DI does not use a fuel pressure regulator so how does it know how much to throw
08-10-2011, 05:57 PM
#2
Boost :)
I've tuned many many turbo charged Supras and done it just as you mentioned with aftermarket adjustable pressure regulators and of course adjusting airflow or fuel injector output as well.
It is my understanding on this truck is that it has at least one wideband O2 sensor and makes it adjustments based on that. I'm sure with the incredible fuel pressure that these motors have, the injector duty cycle can be increased and output can be increased there too, but I don't know enough about DI injectors to know for sure. I've seen made mention in quite a few threads that it has wideband O2's and can make adjustments on the fly to get the A/F ratio more in line with where it should be.
I don't know for sure though! Just my thoughts...
It is my understanding on this truck is that it has at least one wideband O2 sensor and makes it adjustments based on that. I'm sure with the incredible fuel pressure that these motors have, the injector duty cycle can be increased and output can be increased there too, but I don't know enough about DI injectors to know for sure. I've seen made mention in quite a few threads that it has wideband O2's and can make adjustments on the fly to get the A/F ratio more in line with where it should be.
I don't know for sure though! Just my thoughts...
08-10-2011, 06:33 PM
#3
If our truck has a wideband and the pcm tunes the truck accordingly then we should have no problem installing the whole intake, exhaust and even installing a manual boost controller ( replacing the stock boost solenoid). As long as we keep it within its saftey limits (which we don't know yet) .
I'm in debate if i should use my boost gauge and boost controller from my talon(retired) and keep boost at 10 psi, just above the stock boost.
I'm in debate if i should use my boost gauge and boost controller from my talon(retired) and keep boost at 10 psi, just above the stock boost.
08-10-2011, 08:10 PM
#4
Senior Member
The engine's air flow is measured in the mass air flow sensor (MAF). If the EB is like most new vehicles, it also measures engine speed, air pressure, and air temp and does a speed-density calculation to get an air flow number also. It then compares these numbers to look for possible problems. Finally, it does measure air/fuel ratio using one wideband per bank, and can make minor adjustments if it detects errors in the factory tune. Again, if it goes outside of a pre-set range (usually +/- 20%), then it determines there is an error.
The problem with extensive mods is that the computer may pick up too big a difference between the MAF and SD calc's and purposefully negate any improvements, or it could go outside the 20% max change in A/F ratio. As for the manual boost controller, the computer may or may not over-ride changes by changing the signal to the wastegate. If you bypass the boost control solenoid, then the computer MIGHT conclude there is an error if it is unable to reach setpoint.
So. . . for a CAI or exhaust, the changes might be too small for the computer to notice. 3% isn't a big variation and some is allowed. Beyond that, I believe the key is in ECM recalibration.
The problem with extensive mods is that the computer may pick up too big a difference between the MAF and SD calc's and purposefully negate any improvements, or it could go outside the 20% max change in A/F ratio. As for the manual boost controller, the computer may or may not over-ride changes by changing the signal to the wastegate. If you bypass the boost control solenoid, then the computer MIGHT conclude there is an error if it is unable to reach setpoint.
So. . . for a CAI or exhaust, the changes might be too small for the computer to notice. 3% isn't a big variation and some is allowed. Beyond that, I believe the key is in ECM recalibration.
Last edited by engineermike; 08-10-2011 at 08:16 PM.
08-10-2011, 08:58 PM
#5
Senior Member
The ecoboost doesn't have a mass air flow sensor - it only has a MAP. I just took my truck out for a spin - according to my scan tool, at one point the fuel pressure was at 1,400 PSI. This was climbing a hill. It was considerably lower when I went down the other side, so maybe it adjusts it by pulse width and pressure?
Boost PSI was 84 kPA - 12.2 PSI
Boost PSI was 84 kPA - 12.2 PSI
Last edited by p38fln; 08-10-2011 at 09:39 PM.
08-10-2011, 09:58 PM
#7
Senior Member
Never noticed that before, but you're right - there's a sensor just behind the air filter. Not 100% sure what it is, but its in the right spot for a MAF.
Scantools aren't reporting any MAF sensor, though - just zero's for that PID
Ok, you are 100% correct that it has a MAF sensor, I put my VIN# in to www.fordparts.com and the second result in the Sensors list was for the MAF. Maybe I forgot to turn on that PID on my scanner? *oops* lol
Scantools aren't reporting any MAF sensor, though - just zero's for that PID
Ok, you are 100% correct that it has a MAF sensor, I put my VIN# in to www.fordparts.com and the second result in the Sensors list was for the MAF. Maybe I forgot to turn on that PID on my scanner? *oops* lol
Last edited by p38fln; 08-10-2011 at 10:18 PM.
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08-10-2011, 11:38 PM
#8
Senior Member
If our truck has a wideband and the pcm tunes the truck accordingly then we should have no problem installing the whole intake, exhaust and even installing a manual boost controller ( replacing the stock boost solenoid). As long as we keep it within its saftey limits (which we don't know yet) .
I'm in debate if i should use my boost gauge and boost controller from my talon(retired) and keep boost at 10 psi, just above the stock boost.
I'm in debate if i should use my boost gauge and boost controller from my talon(retired) and keep boost at 10 psi, just above the stock boost.
my stock boost is 12psi
Last edited by hellzno; 08-10-2011 at 11:44 PM.
08-11-2011, 12:02 AM
#9
Are you sure that's stock boost? Just because you see 12 psi @ peak does not mean the wastegate opens at that pressure. I'm pretty sure the solenoid is causing it to go up to 12psi. Anyways I'm not liking this info 
. I'm going to try to find out what exactly these turbos have, and see if i can find a flow map. I hope these turbos still have enough flow left.
. I'm going to try to find out what exactly these turbos have, and see if i can find a flow map. I hope these turbos still have enough flow left.
08-11-2011, 07:11 AM
#10
Senior Member
I've noticed that my Scangauge is missing a lot of stuff that I know exists in the ECM. For instance, it displays IAT before the turbo's, but I want to see it after the intercooler. I know it's in there, but the SG doesn't display it. I had to do some monkeying with the thing to get it to read boost and wideband A/F ratio too.
