GEN 2 Flat spot during acceleration.. ANY IDEAS??

[rtmozingo]

Normal mode prioritizes fuel economy over staying in the power band. It will pretty much always skip 2nd and 4th gear.

Considering the shift from 1st to third goes from 3k RPM to 1500, you are losing about 150 hp right there.

Best way to tell tho is flooring it in sport mode with 4A and TC off. You won't skip gears, you will stay in the power band, with near full boost. If you have a dead zone doing that then you have (ordered most likely to least likely) lost traction, have a boost leak, a transmission problem, or a programming problem (good luck).

In case you want a reference video, here was my first ever launch at 1000 miles on the odometer.

Note my rpms never fell below 4500, boost was always near full, and I had no sluggishness at all.

 

[the_revisionist]

If you're not running 93 octane you are doing yourself a dis-service.

Didn't see OP reply to this, but I've filled up with 87 a couple of times while not paying attention; and experienced this same flat spot after. Feels like it's gutless momentarily then starts to pull hard. No T/C light or boost issue, and don't believe it's turbo lag (have owned big turbo vehicles before with lag so am familiar with how that feels). Not experienced this issue when filling up with 93. Truck feels slower and less peppy all around on 87. 93 FTW.

 

[19RaptorPB]

Didn't see OP reply to this, but I've filled up with 87 a couple of times while not paying attention; and experienced this same flat spot after. Feels like it's gutless momentarily then starts to pull hard. No T/C light or boost issue, and don't believe it's turbo lag (have owned big turbo vehicles before with lag so am familiar with how that feels). Not experienced this issue when filling up with 93. Truck feels slower and less peppy all around on 87. 93 FTW.

Every vehicle I’ve ever had has been fed high octane. It’s not T/C and it’s not lag. I’ve owned big turbo vehicles as well.


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[Antho]

Mine feels the same. Can really notice when driving up an incline. I’m gonna data long mine and see if I can find anything.


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[Terp]

I don't think I saw mention of if this issue is from a dead start or when you're already going 30-40mph? 50-60mph? It's still early so I may have missed it. Also what driving mode? I definitely don't seem to experience a dead spot in that rpm range as that is where most of your power starts to show up, and when already going around 30-40mph it typically downshifts to a gear that has it pushing right around 3800rpm if I step on it at that point.

 

[19RaptorPB]

I don't think I saw mention of if this issue is from a dead start or when you're already going 30-40mph? 50-60mph? It's still early so I may have missed it. Also what driving mode? I definitely don't seem to experience a dead spot in that rpm range as that is where most of your power starts to show up, and when already going around 30-40mph it typically downshifts to a gear that has it pushing right around 3800rpm if I step on it at that point.

It happens in normal, sport, and baja. The most noticeable is when I’m going from a dead stop and have my foot to the floor although I feel it while driving normal too. If I go from a dead stop and launch it the RPMs climb normal and power is normal. I would assume like most do, my upper body is leaning forward to physically kind of fight against the throwback from the acceleration. Not overly sitting forward but just slightly.... as it gets into that certain RPM range I can feel the dead spot and my body physically moves further forward on it’s own because of the lack of pull. Once it gets past that dead spot I can feel it pull again. It is really very minimal and I’ve had my wife drive as well as a few friends who are all gear heads like me and not one of them has mentioned it. Because I drive it every day, I’ve become more aware of it. The RPM’s still climb, I’m still making speed but there is still an ever so slight flat spot.

I hope that explains it better


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[Terp]

It happens in normal, sport, and baja. The most noticeable is when I’m going from a dead stop and have my foot to the floor although I feel it while driving normal too. If I go from a dead stop and launch it the RPMs climb normal and power is normal. I would assume like most do, my upper body is leaning forward to physically kind of fight against the throwback from the acceleration. Not overly sitting forward but just slightly.... as it gets into that certain RPM range I can feel the dead spot and my body physically moves further forward on it’s own because of the lack of pull. Once it gets past that dead spot I can feel it pull again. It is really very minimal and I’ve had my wife drive as well as a few friends who are all gear heads like me and not one of them has mentioned it. Because I drive it every day, I’ve become more aware of it. The RPM’s still climb, I’m still making speed but there is still an ever so slight flat spot.

I hope that explains it better


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Definitely helps better explain what you are feeling. Can't say I've noticed the same but I'll pay more attention now. May be the rim/tire combination may be just the way the truck runs through that section of the power band, who knows. I'll definitely see if I notice it when I'm out and about this weekend.

 

[19RaptorPB]

Definitely helps better explain what you are feeling. Can't say I've noticed the same but I'll pay more attention now. May be the rim/tire combination may be just the way the truck runs through that section of the power band, who knows. I'll definitely see if I notice it when I'm out and about this weekend.

I would say you were onto something with the wheel/tire combo but it has done this since day one. I didn’t get the wheels on for almost 2000 miles. I felt zero change whatsoever after the wheels and tires.


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[Terp]

I would say you were onto something with the wheel/tire combo but it has done this since day one. I didn’t get the wheels on for almost 2000 miles. I felt zero change whatsoever after the wheels and tires.


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After driving around today a bit once I read your description I can definitely say I noticed the same thing. Not something that bothers me however it really seems like it is just the gap where the power curve stays flat before the turbos really spool up around 3800rpm.

I also wasn't implying that the rim/tire combo was the sole reason but it may make the effect more dramatic because you said your tires are heavier but rims are lighter. That combo is going to potentially decrease performance because more weight on the perimeter of your setup is going to be harder to spin. Just take a sledgehammer hand swing it back and forth by the end of the handle and then again by the head of you want to see what I mean. Maybe you can find someone else with a Gen2 and compare?

 

[19RaptorPB]

After driving around today a bit once I read your description I can definitely say I noticed the same thing. Not something that bothers me however it really seems like it is just the gap where the power curve stays flat before the turbos really spool up around 3800rpm.

I also wasn't implying that the rim/tire combo was the sole reason but it may make the effect more dramatic because you said your tires are heavier but rims are lighter. That combo is going to potentially decrease performance because more weight on the perimeter of your setup is going to be harder to spin. Just take a sledgehammer hand swing it back and forth by the end of the handle and then again by the head of you want to see what I mean. Maybe you can find someone else with a Gen2 and compare?

Thank you for the reply. The fact that you noticed it makes me feel a whole lot better. After this thread I’ve been realizing that I may be concentrating a little too much on it when I shouldn’t be. The power is there and the flat spot is not so pronounced that other people notice it right away.

About the wheels/tires - I know you weren’t implying it was the sole reason. I just wanted to make sure everyone knew that the flat spot was there beforehand and the only difference I noticed with the wheel/tire combo is a somewhat stiffer ride, but not enough to justify a second thought.

I am going to chalk this up to me over concentrating on the flat spot and move forward. The fact that others have felt it makes me feel a whole lot better. Coming from first generation ecoboost, I didn’t feel that amount of power gain all at once and it made me focus on the flat spot before the power surge. My previous truck was tuned with CAI, downpipes, and cat back exhaust which as a combo made a great improvement but still nothing compared to this. Being I did all the work to that made me notice every little change along the way and I still hadn’t noticed a healthy jump in power like this. Overall I love this truck in every way and I hope to get a lot of reliable years out of it.

I truly appreciate this forum and all the knowledge shared. Thanks guys.


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