Possible Powerloss

[M_trumble]

Had a question for the group. Anyone else in here noticed any type of power loss in their Powerboost? I don’t have anything too official to measure it against, but the old seat of the pants Dyno tells me power is way down. I did a 0-60 run tonight, no load up on the boost and it ran a 7.3. My turbos don’t even start spoiling until after 2k. Is that everyone else’s experience too? It’s a limited with 25k miles on it. I feel like there’d be a check engine light if a turbo wasn’t working. I don’t know. I just feel like it used to sit me back in my seat pretty well and it definitely doesn’t do that anymore.

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[HammaMan]

could be bad gas or your pants-o-meter is on the fritz

 

[Snakebitten]

25,000 miles

Although it's a Powerboost, so technically the motor doesn't actually have 25,000 miles on it, in some ways the drivetrain certainly does.

Fresh Air Filter
Fresh plugs gapped nicely
Fresh 93 octane

Engine coolant at least 180F, but before IAT2 is above ~120-125F
(Powerboost can quickly heat soak the intake and sensor because during each EV event there's no fresh air, and the engine block superheats the intake like a pizza oven)

Traction nannies off.

I bet you can improve what you felt.

 

[Big Dog Daddy]

25,000 miles

Although it's a Powerboost, so technically the motor doesn't actually have 25,000 miles on it, in some ways the drivetrain certainly does.

Fresh Air Filter
Fresh plugs gapped nicely
Fresh 93 octane

Engine coolant at least 180F, but before IAT2 is above ~120-125F
(Powerboost can quickly heat soak the intake and sensor because during each EV event there's no fresh air, and the engine block superheats the intake like a pizza oven)

Traction nannies off.

I bet you can improve what you felt.

How about doing a PCM reset? That will definitely add seat of the pants horsepower right away!

 

[DT444T]

I've seen this several times since owning my PB.

The only time I've ever CAUGHT it was when I was in ECO mode. It wouldn't give boost until 55mph and then it came in like afterburners.

Sometimes the computer wont give boost. It's not Traction Control related or anything. It's gotta be a temperature thing.

 

[M_trumble]

I've seen this several times since owning my PB.

The only time I've ever CAUGHT it was when I was in ECO mode. It wouldn't give boost until 55mph and then it came in like afterburners.

Sometimes the computer wont give boost. It's not Traction Control related or anything. It's gotta be a temperature thing.

That’s good to hear. For me anyway, it’s not all the time. Sometimes it’a froggy and feels great and other times, it feels like the turbos just don’t like to run. It never occurred to me the computers would have much to say about the turbos working or not aside from the wastegate staying open or something. I’ll start paying closer attention to when it happens. I’m used to a 6.2, so these turbos are taking some getting used to. I’m definitely used to more consistent and linear power.

 

[DT444T]

it feels like the turbos just don’t like to run.

Do you have the boost gauge up on your screen? Because that was literally the case for me. No boost.

computers would have much to say about the turbos working or not aside from the wastegate staying open or something.

The wastegate is EVERYTHING when it comes to boost. With the wastegate is open, you're not going to get any boost. And the computer controls the wastegate, directly.

 

[M_trumble]

Do you have the boost gauge up on your screen? Because that was literally the case for me. No boost.



The wastegate is EVERYTHING when it comes to boost. With the wastegate is open, you're not going to get any boost. And the computer controls the wastegate, directly.

Yes, I keep the wastegate on my screen and I’ve had it happen where I can mat the pedal and still see zero boost. I guess the reason I never considered the wastegate being held by the computer is because my old ass is used to the mechanical spring type that just opened at a certain amount of psi. Makes sense they’d use computer controlled ones with sequential turbos though.

 

[Snakebitten]

The engine management logic on these trucks is what the experts call "Torque Management".

It's completely flybywire, as far as the pilot is concerned.

When you depress the accelerator/throttle, you are NOT physically opening a throttle or any other component that is directly connected to the motor(s) on the vehicle. Rather you are simply "notifying" the engine management computer (PCM) of your request. And technically your request is a torque request. You are literally requesting a specific quantity of torque to be delivered to the wheels.

On a Powerboost there is more than one source for torque, so to speak.

Electric drive motor
ICE normally Aspirated
ICE forced induction

Depending on how much torque you are requesting, the software determines the source or mix of sources.

I've been driving Ecoboost F150's for some time and in my opinion the Powerboost is programmed to bring forced induction into the equation with a bit of reluctance compared to the non-powerboost.
Or put another way, it's remarkable just how spirited the Powerboost can accelerate without boost, compared to the Ecoboost.

All for obvious reasons. 3.5 liters combined with the potential of the electric drive motor is surprisingly sufficient at getting this truck down the road. And unless the SOC of the Hybrid battery is already at the lowest range of operation, those wastegates are the last to be called on.

At least from the PIDs that I monitor, it certainly seems so.

 

[DT444T]

sequential turbos

Just a..uh... friendly fyi?

They're parallel twins, not sequential. Sequential means sequenced.

"Sequential turbocharging refer to a set-up in which the engine uses one turbocharger for lower engine speeds, and a second or both turbochargers at higher engine speeds. This system is intended to overcome the limitation of large turbochargers providing insufficient boost at low RPM."

 

[DT444T]

...it's remarkable just how spirited the Powerboost can accelerate without boost,

It REALLY is remarkable. Even when the computer is giving zero boost it's not exactly SLOW. I wish I could set it up for a no-boost test and run it against my TDi VW (140hp) and see which is faster.

 

[M_trumble]

Just a..uh... friendly fyi?

They're parallel twins, not sequential. Sequential means sequenced.

"Sequential turbocharging refer to a set-up in which the engine uses one turbocharger for lower engine speeds, and a second or both turbochargers at higher engine speeds. This system is intended to overcome the limitation of large turbochargers providing insufficient boost at low RPM."

Really?? I thought they were sequential. I know I’d read that before. Maybe earlier versions? I remember the article talking about the first turbo being tuned to hit around 1600 and the second was supposed to hit around 3500 or something. That was how they got such a big torque number so low. That blows me away that’s not the case. I thought for sure they were sequential

 

[DT444T]

Really?? I thought they were sequential. I know I’d read that before. Maybe earlier versions? I remember the article talking about the first turbo being tuned to hit around 1600 and the second was supposed to hit around 3500 or something. That was how they got such a big torque number so low. That blows me away that’s not the case. I thought for sure they were sequential

The turbocharges are Borg-Warner K03 units. They're TINY. This same size turbo was fitted to VW Golf/Jettas with the 1.8L T. That's how a relatively large 3.5L can spool them so easily. Compared to the T-25 (ish) turbos on my 300zx which are significantly larger turbos and a smaller 3.0L engine.

I've never known the 3.5L to use any special trickery to help spool the turbos any faster.

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