The cause of the #8 failures.
Put simply, it is NOT a Factory Ford problem.
Detonation is causing the failures.
The short of it:
Tunes with as much as 5 degrees of 'Global' spark added, knock sensor activity in some cases decreased (exagerating the issue).
The long of it:
These motors are octane limited. From the factory they run low ignition timing due to the following factors:
1. 11:1 compression
2. Variable cam timing which increases dynamic compression
3. Low *motor* octane pump gas fuel
Below is a short list of just a few Factory settings in a GTU6 calibration.
Stoich :14.079
WOT base Lambda: .85 to 5K richening to .82 by 6250 (that's .82 x 14.079)
Individual cylinder timing modifier: -2 degrees from 4-7K RPM on the #8 (but not the only cylinder with reduced timing)
Octane Spark modifier: -3 degrees @ high load
Knock sensor retard max: -6 to 4K dropping to -4 by 6K
Knock sensor retard rate: 1 to 1.5 (that's seconds per degree removed), so it would take 6 seconds to remove 4 degrees at 6K RPM (at a rate of 1.5).
On top of that there are 16 Boarderline knock tables, 16 MTB spark tables with all the conditional modifiers you can think of, including individual cylinder multipliers. (Obviously Ford knows some cylinders run hotter than others)
This is still a good'ol Mod motor and suffers from the same heat issues in the rear of the driver side head as all the others. As evidence the Factory stock tune removes 2 degrees of timing from the #8.
Now for the real 'cause' of the problem....
1. The aftermarket was rushed to produce support for the 2011 Fords. With an all new ECU on top of a new drivetrain, this would normally take a good year of testing to get proper software onto the market, yet tuning support was released just weeks after the 5.0 hit the dealer lots.
2. Due to the design and complexity of the new ECU, the tuning strategy is NOT the same as any previous Ford ECU. This was not realized at first. Torque calculation (for one) plays a much larger role. Widebands, frequency based maff, and variable cam timing have been added just to name a few obvious changes.
3. No tuner/shop in the country was prepared to properly tune these vehicles the way Ford does it....how could they. Ford does not offer tune training classes.
4. Popular datalog software used on previous Fords doesn't work correctly on the 2011's. Go WOT while datalogging and the software drops data, including Knock sensor activity and total timing. To add insult to injury those tuners with Dynojets have ended up with Blown stacks when running the 2011's on their dyno. Now they have no dyno and no data! What's a tuner to do?
5. The old way of tuning an all-motor Ford was employed.... (Ford MUST have tuned these motors just as conservative as previous years right???) Add timing and lean it out. Low and behold it made more power on the dyno, but running in mild detonation does make more power on the dyno.
Those of us with Dataloggers that DO work on the 5.0 immediately saw that adding timing resulted in higher knock sensor activity on pump gas, and we therefore did NOT increase ignition timing.
Now for the 'Fix'....
1. Run STOCK IGNITION TIMING if you are running pump gas!
2. A *Good* custom tuner can make just as much (if not more) with stock ignition timing *if* they tune the variable camshafts correctly. This typically requires a few extra hours of dyno time. And motors with the same mods don't respond the same to TiVCT changes, this means TiVCT tables customized for each vehicle. No mail order plug & play if you want Maximum power out of this new system!
3. Convert over to E85 and run all the timing you want. Kinsler racing has a fuel filter that fits in the stock location yet flows far more than the stock filter. I'd advise a 50-100 micron element when running E85. Again, a Good custom tuner can tune these cars on E85 without issues. If they know where to look Ford even provided 5.0L Ethanol tables to make it fairly easy.
FWIW, I've heard rumors that Ford's solution is to reduce the compression ratio. That will also 'fix' the problem, but at reduced fuel economy and performance.
Put simply, it is NOT a Factory Ford problem.
Detonation is causing the failures.
The short of it:
Tunes with as much as 5 degrees of 'Global' spark added, knock sensor activity in some cases decreased (exagerating the issue).
The long of it:
These motors are octane limited. From the factory they run low ignition timing due to the following factors:
1. 11:1 compression
2. Variable cam timing which increases dynamic compression
3. Low *motor* octane pump gas fuel
Below is a short list of just a few Factory settings in a GTU6 calibration.
Stoich :14.079
WOT base Lambda: .85 to 5K richening to .82 by 6250 (that's .82 x 14.079)
Individual cylinder timing modifier: -2 degrees from 4-7K RPM on the #8 (but not the only cylinder with reduced timing)
Octane Spark modifier: -3 degrees @ high load
Knock sensor retard max: -6 to 4K dropping to -4 by 6K
Knock sensor retard rate: 1 to 1.5 (that's seconds per degree removed), so it would take 6 seconds to remove 4 degrees at 6K RPM (at a rate of 1.5).
On top of that there are 16 Boarderline knock tables, 16 MTB spark tables with all the conditional modifiers you can think of, including individual cylinder multipliers. (Obviously Ford knows some cylinders run hotter than others)
This is still a good'ol Mod motor and suffers from the same heat issues in the rear of the driver side head as all the others. As evidence the Factory stock tune removes 2 degrees of timing from the #8.
Now for the real 'cause' of the problem....
1. The aftermarket was rushed to produce support for the 2011 Fords. With an all new ECU on top of a new drivetrain, this would normally take a good year of testing to get proper software onto the market, yet tuning support was released just weeks after the 5.0 hit the dealer lots.
2. Due to the design and complexity of the new ECU, the tuning strategy is NOT the same as any previous Ford ECU. This was not realized at first. Torque calculation (for one) plays a much larger role. Widebands, frequency based maff, and variable cam timing have been added just to name a few obvious changes.
3. No tuner/shop in the country was prepared to properly tune these vehicles the way Ford does it....how could they. Ford does not offer tune training classes.
4. Popular datalog software used on previous Fords doesn't work correctly on the 2011's. Go WOT while datalogging and the software drops data, including Knock sensor activity and total timing. To add insult to injury those tuners with Dynojets have ended up with Blown stacks when running the 2011's on their dyno. Now they have no dyno and no data! What's a tuner to do?
5. The old way of tuning an all-motor Ford was employed.... (Ford MUST have tuned these motors just as conservative as previous years right???) Add timing and lean it out. Low and behold it made more power on the dyno, but running in mild detonation does make more power on the dyno.
Those of us with Dataloggers that DO work on the 5.0 immediately saw that adding timing resulted in higher knock sensor activity on pump gas, and we therefore did NOT increase ignition timing.
Now for the 'Fix'....
1. Run STOCK IGNITION TIMING if you are running pump gas!
2. A *Good* custom tuner can make just as much (if not more) with stock ignition timing *if* they tune the variable camshafts correctly. This typically requires a few extra hours of dyno time. And motors with the same mods don't respond the same to TiVCT changes, this means TiVCT tables customized for each vehicle. No mail order plug & play if you want Maximum power out of this new system!
3. Convert over to E85 and run all the timing you want. Kinsler racing has a fuel filter that fits in the stock location yet flows far more than the stock filter. I'd advise a 50-100 micron element when running E85. Again, a Good custom tuner can tune these cars on E85 without issues. If they know where to look Ford even provided 5.0L Ethanol tables to make it fairly easy.
FWIW, I've heard rumors that Ford's solution is to reduce the compression ratio. That will also 'fix' the problem, but at reduced fuel economy and performance.
