The following information is meant to be a more detailed explanation of how the new adjustable parameters in the GM 1999-2008 V8 Gas Predators would be applied. All parameters listed may not be applicable to all part numbers.
Torque Management
PLEASE NOTE: Disabling torque management will put greater stress on your drive line. There are three different torque management strategies that you can enable and disable independently. For GM Gas Trucks DiabloSport recommends that the "Upshift Torque Reduction" strategy be left enabled to preserve a good shift feel during upshifts.
- TM Abuse Mode time limit
This is the time in abuse mode as a function of temperature. Turning it off in conjunction with Upshift Torque reduction and %Torque Reduction vs RPM will eliminate torque management. However we have noticed that the shift feel when disabling the upshift torque reduction in trucks and SUV's is reduced and therefore recommend leaving it ON for trucks and SUV's.
- %Torque Reduction vs RPM
Torque reduction as a function of RPM, turning it off in conjunction with TM abuse mode time limit and upshift torque reduction will eliminate torque management. However we have noticed that the shift feel when disabling the upshift torque reduction in trucks and SUV's is reduced and therefore recommend leaving it ON for trucks and SUV's.
- Upshift Torque reduction
Torque reduction control for each individual gear, turning it off in conjunction with TM abuse mode time limit and %Torque Reduction vs RPM will eliminate torque management.
Note:We have noticed that the shift feel is reduced when disabling the Upshift Torque Reduction in trucks and SUV's and therefore recommend leaving it ON for trucks and SUV's.
Injector Slope  Use to correct for injector size changes and also to correct (fine tune) the long term fuel trims. This can be beneficial to increase fuel economy, especially after making other modifications.
- Injector change:
To properly set up injector size changes it is recommended that you increase/decrease the current slope by injector % change.
Example:
24 lbs. injector to 30 lbs. injector
(30-24) / 24 * 100 = 25%
so you increase the injector slope by 25% to get you in the ballpark. If you are stepping down to a lower injector size than stock then you would decrease the injector slope by % change in injector size.
- Determining long term fuel trims:
Long term fuel trims are an accumulated (averaged) value received from the feedback of the Oxygen sensors (o2 sensors) of fuel added or subtracted during closed loop (part throttle) operation. The long term fuel trim ratings are abbreviated as LTFT1 and LTFT2 in the live data monitoring feature of the Predator. LTFT1 denotes the long term fuel trim for bank 1 and LTFT2 denotes the long term fuel trim for bank 2.
These are not STFT1 or STFT2 which are the instantaneous samples taken by the o2 sensors. The samples taken by the o2 senors are aggregated and averaged into the long term fuel trims (LTFT1 and LTFT2). They will show values bouncing around that will never stabilize. That is why you want to monitor the averaged values in LTFT1 and LTFT2.
To verify and tune for long term fuel trims, drive the vehicle for 30 minutes or until warmed up, monitor long term fuel trims until they stabilize and record/remember the average value. The easiest way to do this is to get on the highway, enable cruise control, and sit at 55-65mph while monitoring the data. Ideal values should be in the 0 to negative 2 (-2) range.
- Once you get the average long term fuel trim value you need to make the following adjustments:
- Positive long term fuel trims
For a positive value you subtract that value in percent in the Predator injector slope. It is also recommended to lean (subtract) both WOT (Wide Open Throttle) fuel tables by the same percentage.
- Negative long term fuel trims
For a negative value you add that value in percent in the predator injector slope. It is also recommended to richen (add) both WOT (Wide Open Throttle) fuel tables by that same percentage.
Once adjustment is done and tune installed, take the vehicle out and verify the long term fuel trims per previously described method. Adjust again if necessary.
COT Protection Off Road use only!
Catalytic Overtemp Protection (COT) is used to add fuel to cool down the catalytic converters and it should be disabled only when the catalytic converters are removed. The adding of fuel in this strategy reduces power output. Disabling this strategy when the off-road exhaust is installed will allow the motor to make peak power without the hinerance of the COT strategy. The following strategies are some of the various methods used by GM and will vary depending on the vehicle application:
- COT Enable Temp
The temperature when to enable the COT process, set this high(1200) to disable it.
- COT ON/OFF
Switch to turn COT on or off, set this high to off to disable COT.
Cooling fan adjustment on new LS2/LS4/LS7 and 2007 Truck & SUV's
These newer GM calibrations no longer have fan on/off temps like the older LS1 based calibrations.
The fans now run on a variable speed controller which the pcm controls. The Predator fan parameter is set up to allow individual adjustments per temperature cell in the actual calibration.
The value adjusted is the desired percentage of power to run the fan at that specific temperature, where 0 is the lowest and 99.99 is the highest.
Tire size adjustment
The Predator has two different ways to adjust for tire size.
- First Method
Enter your original tire size then enter the new(actual) tire size.
The Predator will prompt you to put in your original tire size in metric format (ex. 265/75-17), once entered the Predator will then display your entry and you confirm it by pressing enter.
The Predator will then promt you to put in the new (actual) tire size in metric format (ex.305/50-22), once entered the Predator will then display your entry and you confirm it by pressing enter.
You can now press esc to go back to the main modify parameter menu and if no more adjustments are desired press esc again and you will be asked to install modified tune, press yes and let Predator upload new adjusted tune to your vehicle.
To reset the tire size, you can go to reset parameters and then reinstall the tune.
- Second Method
Enter the tire size or the overall tire height
The Predator will ask if you want to adjust it via entering the tire size or by the actual tire height.
- Tire size
Enter the metric tire size displayed on the side wall of the tire (ex.265/75-17) then press enter to confirm.
You can now press esc to go back to the main modify parameter menu and if no more adjustments are desired press esc again and you will be asked to install modified tune, press yes and let Predator upload new adjusted tune to your vehicle.
- Tire height
Measure the tire height using a tape measure and enter that measurement in the Predator, then press enter to confirm.
You can now press esc to go back to the main modify parameter menu and if no more adjustments are desired press esc again and you will be asked to install modified tune, press yes and let Predator upload new adjusted tune to your vehicle.
To reset the tire size, you can go to reset parameters and then reinstall the tune.
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