NGC3 forced open loop tuning

[grimmechanic]

Trying to setup a Jeep Wrangler for Jeepspeed off-road racing with forced open loop tuning (speed density). It's a 2006 TJ, 4.0 stroker. Using the original NGC3 ECM. A lot of competitors in some other classes are just using stand alone aftermarket FI systems, but the rules don't allow an aftermarket FI system (over a certain dollar threshold) for the class we're running. Most of the low dollar aftermarket FI systems are crap and not worth the money for our application.

So far, it looks like the easiest way to force open loop operation is to just set the engine temp range for closed loop function to max (376F?) for the O2 sensors. And I assume that the way to modify F/A ratios is by editing the VE tables. Is this correct? But, I also noticed there's a WOT fuel table that uses Pressure Ratio and RPM that's triggered by TPS voltage. I assume that the Pressure Ratio is the ratio between the sensed MAP and the calculated barometric pressure? Is this correct? Is there any preferred approach to forced open loop tuning with the NGC3?

[rays04gtx]

It's late so I'll only answer the Closed loop, yes bump the temp up the 376.

[rays04gtx]

When I set up a pre-09 Hemi vehicle for track usage only( I know your talking 4.0 jeep...but many of the same tune settings cross over.

1st I find out what RPM it?s going to be staged at, log Accelerator pedal V, Intake MAP, Barometric pressure . Desired FA, VE base and VE Total. STFT and LTFT?s are no longer a concern, Wideband readings come later ??.I don?t care about those at this point?.., I?m not going to grandma?s house with this thing?.It?s a race Car/Truck/Jeep? once the basics are known , we can build a tune.

let?s say your jeep staged on the starting line leaves best at 2200RPMs,you need to get it into WOT at or just after 2200 rpms, so we log TPS V and Accelerator V , since your dealing with Manual jeep ( I hope) Driver Demand tables are not much of an issue?..so we need to know what Pedal Voltage you are commanding @ 2200RPMs, if it?s say 1.26V you want to bring table 44442, down to 1.45ish Volts , I?ve found that you need a .02-.03 cushion.

Next is AFR Since your going in to WOT right away, you need to know what AFR you want to command, and at what Ratio (Manifold MAP/Barometric pressure ) set Table 34243 to your desired AFR starting at the axis cross point of your RPM and P-ratio

I set up a 05 Wrangle this summer for a local 200ft dirt drag here outside Allentown Pa, so using his Jeep as an example.
@1880-1900 RPMS ,Pedal V was averaging 1.33V, TPS V = .90, so I set table 44442 to 1.65V .
@ 1880 P-Ratio was .75-.77(Manifold MAP of 11.00-11.20 / Baro pressure of 14.5-14.7)

we wanted to start with a AFR 12.7 to 1 ,so .0092+stoich of .0695 gives us .0787 FA (See screen grab) I reset the RPM scale in Table 34243 to include a cross point of 18XX rpms and 65 P-ratio.

The other screen grab is what was done to keep this Jeep in open loop.

Attached is a Tune that came out of the repository here on HPtuners , that I modified as an example of what I did to set up the 05 , transposed over to an 06 Tune file.

once we had a starting point and a few"test" hits the next step was to dial in the VE tables which is where the wide bands were put to good use.

[grimmechanic]

Finally got this project to fly in forced open loop and got a decent tune for a stock 4.0

Now, I have a 4.6 stroker project with some cam and compression. This is an NA engine that should be producing somewhere around 300-320 hp. Enough that I need to run 34 lb injectors from a 2011-2015 Mustang GT. Now, I understand that I can go the same way as I did with the first mostly stock 4.0 and make adjustments in the VE tables, but I haven't figured out how to change the 3450 and 3452 tables without exceeding the range in the bottom cell of 3452. 3450 and 3452 are under Fuel/General/Injector Control. The stock tune in table 3452 has the last cell at 1.00680 g, and the max range limit is 1.02398 g. I need this in the range of 1.408 g for the 34 lb/hr injectors.

Is it even necessary or desirable to adjust 3450 and 3452 for the larger injectors? Or just make up for it with the VE tables. This build is going to be a street build and I need to keep the emissions systems/O2 sensors functional.

[rays04gtx]

Finally got this project to fly in forced open loop and got a decent tune for a stock 4.0

Now, I have a 4.6 stroker project with some cam and compression. This is an NA engine that should be producing somewhere around 300-320 hp. Enough that I need to run 34 lb injectors from a 2011-2015 Mustang GT. Now, I understand that I can go the same way as I did with the first mostly stock 4.0 and make adjustments in the VE tables, but I haven't figured out how to change the 3450 and 3452 tables without exceeding the range in the bottom cell of 3452. 3450 and 3452 are under Fuel/General/Injector Control. The stock tune in table 3452 has the last cell at 1.00680 g, and the max range limit is 1.02398 g. I need this in the range of 1.408 g for the 34 lb/hr injectors.

Is it even necessary or desirable to adjust 3450 and 3452 for the larger injectors? Or just make up for it with the VE tables. This build is going to be a street build and I need to keep the emissions systems/O2 sensors functional.

Just run them, do your VE tuning, then you can tune the injectors