2715
PCMTec Editions Required: Any Editions*.
*Ghost Cams are just a modification of the VCT tables which can be achieved (mostly) in Enthusiast or Professional, but the best results are achieved in the One-Car Workshop or Workshop Edition.
NOTE. This is NOT emissions compliant. This cannot be done on a road car, it must be for vehicles that are used on a racetrack or a power cruise event, etc. This is the same as using aftermarket camshafts. The unburnt fuel will not be cleaned up by the catalytic converter and you will be releasing high levels of carbon monoxide (NOx should be quite low as it is running rich, not lean). Do not leave your car idling in a shed with poor ventilation. E85 is much safer than Petrol however it is still not recommended to breathe in the gasses.
Firstly the VCT works by the PCM calculating an intake camshaft position, it then adds the calculated overlap angle to this position to calculate the position of the exhaust cam.
E.g.:
VCT_Intake_Cam = Calculated Intake position
VCT_Exhaust_Cam = VCT_Intake_Cam + Overlap_Angle
Finally to confuse things the PCM then adds/subtracts from the intake and exhaust cam based on boost error. Note this is only in the FGs. This will not affect idle however it will affect your vehicle's performance depending on how you have set up the boost control.
To achieve a ghost cam we need to understand how the overlap angle is calculated.
There are 3 modes of VCT operation
cam source == 4 is Idle mode
cam source == 99 is VCT Fault/Not Installed mode
Cam source == 3 is power/full throttle mode
cam source == 2 is part throttle mode
Now in idle mode, the camshaft overlap is capped by the same table that determines the intake camshaft position, so you cannot achieve any overlap, the best you can do is set both the intake and exhaust camshaft to 50 degrees which will give you some lump.
An easy solution to this problem is to force the PCM into cam source == 3 at all times. This means the main VCT tables are used at all times making tuning the vehicle much easier.
To force the camshaft to use the main maps at all times simply set these scalars out of range to -1000 rpm.
auF1079 (VCT Closed throttle disable RPM) set to -1000
auF1035 VCT Closed throttle enable RPM) set to -1000
Now to get a ghost cam the following tables need to be modified
auF0115 (BF/FG)
Maximum allowed overlap angle based on RPM and Oil Temp. Set the lower half of this table to 80 degrees.
Now we can change the commanded overlap at idle via auF16492 (BF) auF0116 (FG).
Here you can see I have commanded 35 degrees of overlap at a TPS reading of 5, this means as soon as you touch the throttle the cam timing goes back to stock making car parks and low load no problem.
You also need to modify auF16503 (BF) auF0097 (FG) to have similar timing values in the low load/low tps cells. In this example I set 600 rpm to -30 deg to stop the vehicle from stalling, this will also increase the lope when the rpm drops low as the decreased overlap will kick the rpm back up again.
I changed the auF0494 (BF) auF16487 (FG) (TPS) axis to 5 in the lowest cell, this means you keep the commanded overlap when hot/cold.
Finally, I suggest increasing your idle rpm to 1000 rpm to avoid stalling.
In the FG there is an overlap adder for speed density auF2260. You will need to put smaller values in the 30 and 60-degree overlap cells. This will clean up the idle fuel trims. BEWARE that some FGs command 30+ deg of overlap when coming onto boost, if you modify this table you may be modifying the WOT fueling as well. If you are using a multi-tune another way to clean up the idle AFRs is to simply add the slope of the map table to the tune. auF2928 may be a more suitable table to use for the FGs as it also has an RPM component.
It is also recommended to disable LTFT when the ghost cam is active by adding this to your ghost cam tune. This will prevent closed-loop fueling from maxing out by adding fuel (auF0164).
Beware that if you command too much overlap you will foul your plugs and the car will misfire until they clean up. 35 degrees is quite a lot and I would only recommend this as a gimmick, not in a daily driven car.
Here is a video of what the above settings will sound like.
As you can see low speed reversing etc is not a problem.
Edit: This is possible to do on a BA if you use HAAT3VC or possibly HAAT2xx as these are the late models FPV BAs that had independent cam control.
Here is a procedure to upgrade a BA to use the F6 operating system.
Edit 2: You can increase the lope quite dramatically by modifying this table (auF11706). This is the proportional gain of the idle spark feedback algorithm. By increasing it to 5000 it will toggle between min spark (-7) and max spark (MBT ~25 deg) causing even more lope. This table is only available in the One-Car Workshop or Workshop Edition.
In the 5.0 Coyote V8s, we have found the figures below tend to give quite a good result without even touching the cam timing. There can be hesitation when transitioning from idle to throttle, so you may need to add timing to the low-load main spark map to help the transition. In the 6 cylinders, the numbers don't seem to affect drivability much so you can put silly figures like the above without issue.
If you are using the multi-tune to do ghost cam you can add the following table to the ghost cam tune to increase your idle rpm, this means the non-ghost-cam tunes can retain a completely stock idle rpm.
Here is an example of the required tables in a BF to add ghost cam to tune 4 only if utilizing the multi-tune functionality.
Value files are now available for FG and BF.
