WOT Power Dip around 5000RPM

[CustomS550]

Hey, team!

The engine exhibits a very pronounced power dip under WOT at around 5k rpm, and then picks right back up until it runs out of breath in the typical Ecoboost fashion. This is an intermittent occurrence, but it happens more often than not.

Has anyone else experienced this?

Car is full bolt on with a Hypertech tuner. No CEL. I can't test with the factory tune due to the aftermarket downpipe.

Thanks!

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[w3rkn]

93 octane?

 

[CustomS550]

Only

 

[TeeLew]

Hey, team!

The engine exhibits a very pronounced power dip under WOT at around 5k rpm, and then picks right back up until it runs out of breath in the typical Ecoboost fashion. This is an intermittent occurrence, but it happens more often than not.

Has anyone else experienced this?

Car is full bolt on with a Hypertech tuner. No CEL. I can't test with the factory tune due to the aftermarket downpipe.

Thanks!

I had my bone stock HPP dyno'd earlier today and saw exactly this. At about 5000 rpm, it seems like the calibration goes to shit. Mine never really recovers between there and red line. Further, it's running a super fat at ~9.0:1.

It seemed to do it less in 3rd than 4th gear. The guy I was working with thought it might be some sort of WOT timer. Maybe, after X seconds, the ECU just starts throwing fuel at it to keep the cylinder cool?

 

[CustomS550]

I had my bone stock HPP dyno'd earlier today and saw exactly this. At about 5000 rpm, it seems like the calibration goes to shit. Mine never really recovers between there and red line. Further, it's running a super fat at ~9.0:1.

It seemed to do it less in 3rd than 4th gear. The guy I was working with thought it might be some sort of WOT timer. Maybe, after X seconds, the ECU just starts throwing fuel at it to keep the cylinder cool?

Feel like posting the graph? I think that you're seeing the typical Ecoboost redline taper. Ford does that to keep the turbo and the catalytic converter from burning up.

 

[TeeLew]

Feel like posting the graph? I think that you're seeing the typical Ecoboost redline taper. Ford does that to keep the turbo and the catalytic converter from burning up.

No, it's different. The ECU is stepping in to protect *something*, but it's been done poorly. It's not a conventional roll-off on the top end.

 

[CustomS550]

No, it's different. The ECU is stepping in to protect *something*, but it's been done poorly. It's not a conventional roll-off on the top end.

Nice looking graph! Much better than the non-HPP engines, that's for sure. Are you on the factory intercooler?

 

[K4fxd]

Looks to me like it is trying to save the cats.

Turn off the cat temp protection in the tune and see if it goes away. Might be some other parameters like manifold protection and turbo ect...

 

[TeeLew]

The guy running the dyno and I figured that either it was on a timer, or trying to save the cats/avoiding detonation problems. Either way, this is a cool engine running good gas on a cool ambient day. There's no reason why this car can't make it though 15 seconds at WOT without going into some protection mode while pouring raw fuel through the engine.

 

[K4fxd]

Hopefully you logged all the torque reduction parameters and you will know what happened.

Looking at the AFR curve looks like cat protection. I'd start there

 

[TeeLew]

Hopefully you logged all the torque reduction parameters and you will know what happened.

Looking at the AFR curve looks like cat protection. I'd start there

I didn't have anything hooked up to log, I just wanted to get a baseline on power. It doesn't really matter. Next time on the dyno will be significantly different engine mapping. It's not like I'm going to try to make the stock cal work.

 

[ihasnostang]

on stock tune ive seen calculated cat temps on my AP of 1730 F after a 20min track session. i can post a excel datalog of cobb OTS stage 2 during a 1/4 mile pass with cat temps logged (1558 peak) if interested

 

[TeeLew]

on stock tune ive seen calculated cat temps on my AP of 1730 F after a 20min track session. i can post a excel datalog of cobb OTS stage 2 during a 1/4 mile pass with cat temps logged (1558 peak) if interested

That seems a lot different than 20 seconds.

 

[CorvZ061]

Going 9:1 AFR at 5k with a power loss at the same time makes sense, 9:1 is way to rich and will cause a misfire too. That’s definitely cat protection because the fuel cools the cat as well, but damn that’s extreme even for Fords crappy stock tune

 

[CustomS550]

Going 9:1 AFR at 5k with a power loss at the same time makes sense, 9:1 is way to rich and will cause a misfire too. That’s definitely cat protection because the fuel cools the cat as well, but damn that’s extreme even for Fords crappy stock tune

That's fairly standard for a factory forced induction tune from my experience

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