TGP Code Injector flow vs Base fuel constant

[Guest]

The trend has been to change the fuel injector flow rate, flow per single pulse and base constant at desired EGR.

If both flow rate settings work properly, there should be little to no change of the base constant required because you've effectively accounted for the injector size increase with the two prior settings, lowering the base constant afterward should effectively lean out the mixture.

So except for a small change of the base constant, it should remain pretty much the same plus or minus a little fine tunning, in other words ther is no reason my base constant should be as low as I have it set; 40 which I arrived at by listening to idle however during a test drive it appeared to be very lean and now with WBO2 monitoring at part throttle in neutral it is going as high as 19:1 so the base constant is definately going back up to normal.

That explains the hunting during idle.

Am I reasoning correctly?

I also accidently made a single inject calculation based on the difference in engine size instead of the difference in injector flow rates.

[SappySE107]

Go set your injector flow rate and flow per single pulse to FFFF in the hex, or 0000. It does nothing. Constant vs EGR is the only injector constant I know of.

[Joseph Upson]

Go set your injector flow rate and flow per single pulse to FFFF in the hex, or 0000. It does nothing. Constant vs EGR is the only injector constant I know of.

Thanks for that info, I'll make the proper scale based on the difference in flow rates between the injectors in the EGR vs BPC

[merlot566jka]

woah, foreign language alert.

[Joseph Upson]

woah, foreign language alert.

That's straight talk. First I made a correction for the injector size increase as if it were being used for the 3.1 which brought the BPC down to about 56 from 105 because the injector flow rate increased by nearly 50% so I reduced the BPC by the amount of increase in injector size.

Then I calculated the increase in engine size and increased the new BPC by that amount to arrive at 70 which is 30 points higher than what it was set at previously so I'll pull fuel from the tables from here and add wherever necessary. Hopefully I will be much closer than previously.

[SappySE107]

Do you know the correct math for BPC? I have the equation, and actually did it a long time ago for the mustang injectors. I have never been able to do it since.

[Joseph Upson]

Do you know the correct math for BPC? I have the equation, and actually did it a long time ago for the mustang injectors. I have never been able to do it since.

I just divided it out to number of BPC points per litre for the 3.1, multiplied it by 3.9 then reduced it by the amount of injector flow increase above the stock injectors.

[SappySE107]

Base Pulse Constant Vs Desired Egr Constant =
1461.5 * (egr Factor)(liters/cyl)/(injector Rate)

Injector Rate Is In Gm Per Sec

[Joseph Upson]

Base Pulse Constant Vs Desired Egr Constant =
1461.5 * (egr Factor)(liters/cyl)/(injector Rate)

Injector Rate Is In Gm Per Sec

EGR is disabled.

33.7 lb/hr * 1hr/3600sec * 16 ounces/lb * 28.4gm/ounce = 4.253688 grm/sec

3.9L/6cyl = .65 L/cyl

(1461.5 * 1 (egr disabled) * .65L/cyl)/4.253688 = 223.33

That's just a tad bit high isn't it?

Stock is 105 in Tunerpro and Tunercat but Tunercat has another BPC value listed under constants that's about 180 suggesting it has a BPC constant factor that either is missing from Tunerpro or is synonymous with the Gal/hr entry in Tunerpro. Usually Tunercat is pretty good about being spot on in that if the value is available to be changed it will have an effect. Plus, 180 is much closer to the calculated value above if I did so correctly.

[Joseph Upson]

I just upgraded to TunercatRT to see if I'll have better luck tuning with it. I just checked the BPC in the constants menu and it is registering 233 after the adjustments I made in TunerproRT so there is a units difference I guess. Since the test drive improved and the AFR gauge is still showing a bit rich I'll lower a little at a time to see if the rich condition clears up.

The rpm vs VE table seems to work pretty well so far.

[SappySE107]

units for sure. You were giving me hex. Get the a1.doc file off this site and go the egr vs bpc. You will see what I am talking about. You should get a .xxx value, like .155 or something. Thats the constant with the correct hex conversion.

[Joseph Upson]

units for sure. You were giving me hex. Get the a1.doc file off this site and go the egr vs bpc. You will see what I am talking about. You should get a .xxx value, like .155 or something. Thats the constant with the correct hex conversion.

TunercatRT certainly has TunerproRT licked in this area. As mentioned earlier there is a stand alone BPC listed under constants in Tunercat and it is not far from the value I calculated. In addition to that the car is running much better now as a result of changes made to that value to a little less than the value I calculated.

Since the engine is still running a little rich I believe I'll work on the timing increase a little more before pulling more fuel.

Do you know the formula for converting 104 units of manifold air temperature to degrees?

[SappySE107]

What hex address is it changing?

104 units? I dont even know what you are talking about now. what file are you using with tunerpro? The software is only as good as the definition file it is using.

[IsaacHayes]

http://www.moates.net/files/4)%20Datastream%20Definitions/ALDLstuff.zip

Look up the TGP info in that and it will tell you what is needed to convert the units the $8F uses to degrees.

[Joseph Upson]

What hex address is it changing?

104 units? I dont even know what you are talking about now. what file are you using with tunerpro? The software is only as good as the definition file it is using.

It's a definition issue, I had the same scenario with the MAP reading displayed as units instead of kpa. There is a formula for converting the units which can be inserted at the proper line in the def file to give the reading in the desired units.

I'm using the latest TGP definition file that I'm aware of.