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So what’s 100% then?
in your case 100% is the solenoid passing all available boost to the WG's to force them open. Same theory for the electrical WG's, but some Read 100% as "fully closed".

For example, my 2014 F150 shows 0% as fully open and 100% as fully closed. My Wife's ST is the opposite, 100% is fully open and 0% is fully closed. In both of these examples, they are Vacuum WG's and not Electronic.

If you want to confirm, have a peak at your logs, usually at lower RPM of a WOT run, the WG's don't have to be as far closed to target boost levels. So as you go higher in the RPM of the pull, the WG's are closing more to meet the demand and flow more #/min
 

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in your case 100% is the solenoid passing all available boost to the WG's to force them open. Same theory for the electrical WG's, but some Read 100% as "fully closed".

For example, my 2014 F150 shows 0% as fully open and 100% as fully closed. My Wife's ST is the opposite, 100% is fully open and 0% is fully closed. In both of these examples, they are Vacuum WG's and not Electronic.

If you want to confirm, have a peak at your logs, usually at lower RPM of a WOT run, the WG's don't have to be as far closed to target boost levels. So as you go higher in the RPM of the pull, the WG's are closing more to meet the demand and flow more #/min
Yes that’s true because sometimes when cruising with very little throttle I’ll see 40% WGDC. So the further the wastegates are open at WOT the further the turbo is being pushed right?
 

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You would have to log to see what it actually is, but they don't fully open. They will set to the Boost commanded based on the torque commanded and how much of that torque is coming from timing.
I’d have to look back at my logs, but right after a huge WOt pull, right when I let off I’d see 99.99% or 100% sometimes.
 

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I’d have to look back at my logs, but right after a huge WOt pull, right when I let off I’d see 99.99% or 100% sometimes.
I could have read his question incorrectly, but I was saying that during a WOT pull, the WG's should not go full open. When you cut throttle, I would expect them to go full open to dump any boost being produced as the motor doesn't need it when you're cutting throttle.
 

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Yes that’s true because sometimes when cruising with very little throttle I’ll see 40% WGDC. So the further the wastegates are open at WOT the further the turbo is being pushed right?
Totally depends on what's being asked of the turbos to produce. The further the WG's are being forced closed, the harder the turbo is working from my understanding. The more the WG's are closed, the more exhaust gases are being directed to the turbine of the turbo and the faster it is spinning and producing more boost.
 

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Totally depends on what's being asked of the turbos to produce. The further the WG's are being forced closed, the harder the turbo is working from my understanding. The more the WG's are closed, the more exhaust gases are being directed to the turbine of the turbo and the faster it is spinning and producing more boost.
Right. So technically if you are running more power, the wastegates will be further open, allowing more of that exhaust gases to escape, but the engine has so much power that it’s still spinning that turbo to 20psi or so just as an example.
 

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Aha - I must have misunderstood the purpose of the wastegate. It needs to be closed to create boost, then when the boost is no longer needed, it opens to relieve the built up pressure, right?
 
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Think of the wastegate as a diverter valve. Turbos are honestly a pretty stupid device... there's no electronic control that says "hey, turbo, make 14lbs of boost" or "turn X rpms". You control the turbo by controlling the exhaust flow. If the wastegate didn't exist, 100% of the exhaust would go across the turbo 100% of the time. There would be times when you don't want boost (such as when you dump the throttle) and would get it anyway (leading to surging and other weird behaviors)... and then the first WOT run would massively overspeed the turbos. It'd be crazy fast, once... it would be a competition to see if you spin the turbo bearings, lift the head gaskets, or window the block first.

Note that this doesn't (always) apply to engines with variable geometry turbos, like the problematic 6.D'OH! Powerstroke. The turbo is controlled by varying the vanes on the turbo wheel to change boost pressure. Only in the 6.0, sooty diesel exhaust being recirculated (because emissions) would carbon up the vanes, coke, and then the vanes would stick, leading to an overboost condition. When I dumped my 05 F350 (I traded it in while it was on the rack for the third major engine repair) it was making 67psi boost at WOT. Needless to say, the head gaskets didn't like that too much.

Now, how all this works in relation to engine RPM and overall performance on the EBs is beyond me. My instinct tells me that there's an interrelationship between engine load, RPM, boost, and wastegate duty cycle. With all else being the same, a more-closed wastegate should produce more boost and more power (up to the kaboom). But the wastegate setting to produce, say, 15lbs. of boost (which is probably secondary to what really matters, which is the desired airflow rate) is likely different when you're in 10th gear leaning into the throttle versus when you're in 3rd gear on a WOT run. And that's where all these zillions of tables that the guys who tune talk about.

I'd pay reasonable amounts of good money for a "tuning the 3.5 Ecoboost for dummies" class just so I could understand it all a little better.
 

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Think of the wastegate as a diverter valve. Turbos are honestly a pretty stupid device... there's no electronic control that says "hey, turbo, make 14lbs of boost" or "turn X rpms". You control the turbo by controlling the exhaust flow. If the wastegate didn't exist, 100% of the exhaust would go across the turbo 100% of the time. There would be times when you don't want boost (such as when you dump the throttle) and would get it anyway (leading to surging and other weird behaviors)... and then the first WOT run would massively overspeed the turbos. It'd be crazy fast, once... it would be a competition to see if you spin the turbo bearings, lift the head gaskets, or window the block first.

Note that this doesn't (always) apply to engines with variable geometry turbos, like the problematic 6.D'OH! Powerstroke. The turbo is controlled by varying the vanes on the turbo wheel to change boost pressure. Only in the 6.0, sooty diesel exhaust being recirculated (because emissions) would carbon up the vanes, coke, and then the vanes would stick, leading to an overboost condition. When I dumped my 05 F350 (I traded it in while it was on the rack for the third major engine repair) it was making 67psi boost at WOT. Needless to say, the head gaskets didn't like that too much.

Now, how all this works in relation to engine RPM and overall performance on the EBs is beyond me. My instinct tells me that there's an interrelationship between engine load, RPM, boost, and wastegate duty cycle. With all else being the same, a more-closed wastegate should produce more boost and more power (up to the kaboom). But the wastegate setting to produce, say, 15lbs. of boost (which is probably secondary to what really matters, which is the desired airflow rate) is likely different when you're in 10th gear leaning into the throttle versus when you're in 3rd gear on a WOT run. And that's where all these zillions of tables that the guys who tune talk about.

I'd pay reasonable amounts of good money for a "tuning the 3.5 Ecoboost for dummies" class just so I could understand it all a little better.
Reach out to the Tuning School. They have a good class and a really good teacher.


Sent from my iPhone using Tapatalk
 

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Think of the wastegate as a diverter valve. Turbos are honestly a pretty stupid device... there's no electronic control that says "hey, turbo, make 14lbs of boost" or "turn X rpms". You control the turbo by controlling the exhaust flow. If the wastegate didn't exist, 100% of the exhaust would go across the turbo 100% of the time. There would be times when you don't want boost (such as when you dump the throttle) and would get it anyway (leading to surging and other weird behaviors)... and then the first WOT run would massively overspeed the turbos. It'd be crazy fast, once... it would be a competition to see if you spin the turbo bearings, lift the head gaskets, or window the block first.

Note that this doesn't (always) apply to engines with variable geometry turbos, like the problematic 6.D'OH! Powerstroke. The turbo is controlled by varying the vanes on the turbo wheel to change boost pressure. Only in the 6.0, sooty diesel exhaust being recirculated (because emissions) would carbon up the vanes, coke, and then the vanes would stick, leading to an overboost condition. When I dumped my 05 F350 (I traded it in while it was on the rack for the third major engine repair) it was making 67psi boost at WOT. Needless to say, the head gaskets didn't like that too much.

Now, how all this works in relation to engine RPM and overall performance on the EBs is beyond me. My instinct tells me that there's an interrelationship between engine load, RPM, boost, and wastegate duty cycle. With all else being the same, a more-closed wastegate should produce more boost and more power (up to the kaboom). But the wastegate setting to produce, say, 15lbs. of boost (which is probably secondary to what really matters, which is the desired airflow rate) is likely different when you're in 10th gear leaning into the throttle versus when you're in 3rd gear on a WOT run. And that's where all these zillions of tables that the guys who tune talk about.

I'd pay reasonable amounts of good money for a "tuning the 3.5 Ecoboost for dummies" class just so I could understand it all a little better.
I actually think that, with the stock vacuum actuators, Ford did a really good job of tuning safety into them. Mine blow open almost exactly where the turbos should be maxing out. My WGDC will hit 100% but my turbos never overspeed.

Ive heard the electric actuators will hold shut no matter what.
 
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Just as a reference, I did a test to verify my WG operation by disconnecting the vacuum (boost) source. The boost would top out at 12psi, which is exactly what you would expect for a 5psi spring.


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I dont even need to chime in anymore. You all have learned well! Great information for OP.
 

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Wasted forum space with an obscure post earlier this week but will try a different question. Wastegate percentage seems the inverse of WGD X, on SCT PID's, only with completely different terms in numbering. Anyone want to interpret this?
Rectangle Slope Screenshot Parallel Font


SCT BDX with the LiveLink Gen2 program. The graph represent a 0-80 WOT 1st 2nd into 3rd. Or is it just a bunch of squiggly lines? KM
 

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Wasted forum space with an obscure post earlier this week but will try a different question. Wastegate percentage seems the inverse of WGD X, on SCT PID's, only with completely different terms in numbering. Anyone want to interpret this?
I'm not around my software. Is WGD X a DMR where WG % is a PID? Could simply be how the data is being read... at the end of the day, if they give the same info (albeit one inverted), then it should work.
 

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"Is WGD X a DMR where WG % is a PID?"
Both PID's on my SCT BDX and LiveLink, far as I know. Not sure how to read but inverted yes but a solid bottom to the %. KM
 

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I'm not around my software. Is WGD X a DMR where WG % is a PID? Could simply be how the data is being read... at the end of the day, if they give the same info (albeit one inverted), then it should work.
WGDC X is the X axis of the Wastegate table. If you are logging a histogram, this would be your X channel.
 
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I'm not around my software. Is WGD X a DMR where WG % is a PID? Could simply be how the data is being read... at the end of the day, if they give the same info (albeit one inverted), then it should work.
A bit of looking around and percentage is a PID, WGDC X is a DMR (another term to learn about), described as "canister pressure". KM
 

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A bit of looking around and percentage is a PID, WGDC X is a DMR (another term to learn about), described as "canister pressure". KM
Canister pressure and exhaust mass fraction(faction that passes through turbine vs wastegate) are the axis’ of the wastegate tables.

You can log mass fraction as well.
 
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For a person (like me) who grew up tuning vehicles by ear, a stopwatch, and a marked section of back road, the logs offer an overload of info. I am slowly picking my way thru the maze! KM
 
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