Hi Bottlefed & everyone,

A few comments & I'll get to answering Bottlefed's original questions, part of which I missed earlier..............

While it's true that the best short-cab 2WD 99 & up 260 hp 5.4 F-150's will run about a 15.7 in spring or fall weather, just as many of them will run 16.2 instead.

Now when we have a scenario in which a vehicle's performance *changes* by a half second with no mechanical configuration change, *and* that is happening in virtually identical atmospheric conditions (which just about never actually happens, contrary to a lot of what gets assumed or claimed, there will virtually always be *some* difference in the exact temperatures, humidity & baro pressure levels, etc.), then we might potentially have a cause for concern. But there is no concern just because a particular vehicle runs slower or quicker than another identical vehicle, that happens all the time - it's normal production variance. And we see more of that in these F-150's than perhaps any other vehicle - they have more different factory PCM calibrations than any other vehicle made, as there are more F-150's built (by far) than *any* other vehicle in this country.

And even with the same PCM code, they can still vary - for example, in a tuning R&D session like we just wrapped up last night in Florida for the 2004 F-150's 3-valve 5.4 motor, even with the exact same PCM code (in this case a pair of BME8's), we saw 8-10 HP differences at the wheels between those 2 identical vehicles, both tuned and stock, just depending on how many miles it had been since the last time the PCM was cleared - this goes to Bottlefed's original question, can adaptive learning have this kind of effect - yes!

So performance variances among identical vehicles, even with the exact same PCM calibration (tuning) sometimes, can and do happen - perfectly normal. It's only when we see a documented *change* in a vehicle's performance with no changes made to the vehicle that we should consider that to be worth taking a look at to see why.

Most often (when it's not just the normal adaptive changes), it's the O2 sensors - they *do* affect performance just like they affect fuel mileage and driveability - the impact of worn O2 sensors almost cannot be overstated, but few people accept this because the deterioration is gradual - until they pop in a fresh set of O2's & see the difference. Let a new O2 get a hint of coolant, or some octane booster on it, and bingo - instead of getting a normal 30K-50K miles service life, you could have only 5K miles of optimal operation.

Now in *this* case (getting back to the original post of this thread), Bottlefed's question was, can this difference in performance he is seeing be due to adaptive learning?

Absolutely!

Most daily drivers will lose a few percent of their power just due to the fact that their role is a daily driver - most daily drivers see a fair amount of relatively conservative driving back & forth to work every day, a lot of just "cruising" - where the driver is not demanding heavy power frequently - and so over time, miles & drive cycles, you can lose a few percent of your power. And that sure can make a 1/2 second difference in acceleration times, for example. This is why many times guys will clear the PCM in their daily driver as soon as they get to the track, in an effort to get every last tenth of a second of performance out of their daily driver. You can do just about the same thing for your performance by making dozen or so passes, but that's really pounding on the vehicle - clearing the PCM is kinder & quicker.

Bottlefed - If the performance of the vehicle is not back up to snuff by just clearing the PCM, then it's time to look at other things - usually it's just weather variance, but if you feel it's not, then it's time to take a look at the basics - make sure the MAF's hot wire is clean and the upstream O2 sensors fresh, and that the fuel in the tank is actually the best quality - even fuels at the same station can vary, especially going into fall, as that is when reformulated fuels are put into use in almost all parts of the country - and that will *always* cause performance and fuel mileage both to drop, every single time, without fail. This is due to the oxygenation of the fuels, which causes a lower BTU content (energy).

So clean the PCM & see how it runs, first off - and if you have *ever* used any octane booster, or if that truck has 30K or more miles on it, go ahead and replace the 2 upstream O2 sensors as well - since it's a 2002 hopefully it's new enough that you don't have that many miles on it yet, and hopefully you've never played with octane booster - but if either of those factors is present, then replace the upstream O2's - the downstream units can stay in place, as they don't affect A/F's. That should get your performance back up to snuff, assuming we don't have a problem elsewhere.

And by the way, while the K&N drop-in air filter doesn't do a whole lot (nor should anyone ever expect such a mod to ever be felt in the seat of the pants or to lower the ET's significantly in a 2-3 ton truck), it *does* in fact give you about 4-5 more HP, just to let you know. So it did make a difference, you got another 4-5 HP from it which is a fine return on investment, actually - you got a 1 HP gain for roughly every $10 you spent on that filter and that's not a bad rate of return. But we have to remember it's a very minor performance mod, so you're not going to get a lot from it - that's to be expected - you can make 3 times that much power gain by putting a proper intake kit on it, preferably the Air Force One, as it gains the most power. Just FYI............

Overall, it looks to me like what's going on there Bottlefed is simply variance in performance due to small changes in atmospheric conditions - which is why you can't make an apples to apples comparison of times run on different days, that's always been true, and it's even more critical in modern computer controlled vehicles.

When you make less power in these trucks, it's going to show not only in the trap speed, but also in the short times - *especially* the short times. Why? Because that's when you've got to get that 2-3 ton behemoth moving from a *standstill*, and every HP less you have makes your short times just that much worse with each additional pound of vehicle weight (mass) - in other words, you usually see *more* of this effect in the short times in heavier vehicles than in lighter vehicles - basic physics. This is just another of so many areas where things work a bit differently in these trucks than they do in a 3400 lb. Mustang or a 3600 lb. Camaro, etc. - you've got a lot more mass there, and power drops show most in the short times as a result, whereas in a lighter musclecar it's seen more in the trap speed than the short times.

All in all, not being able to see or drive (let alone diagnose) the vehicle, given that's it's pretty new I think this is most likely just a simple matter of a bit of adaptive strategy at work along with trying to compare times run on different days - which you can't compare apples to apples, as just a small change in baro, humidity, etc. can make significant differences in performance.

But please do feel free to give us a call to go over this in more detail, if you'd like to.

Best of luck & Merry Christmas!

 

Mike, you are right, and trust me being a long time bracket racer I know what weather plays in performance. Thats why i gave you the comparison I did. It was 3tenths slower in far better weather a week apart.

This is a condition in witch favors heavy on the cooler night, yet it was running slower on that night, now I dont remember the exact bar of pressure, but we dont get big high and low pressure systems down here often this time of year.

There is no need for me to use octane booster, so I never had done it. I also just rolled over 30000 while at the drag strip sunday. Maybe this can give you alittle better feel for whats going on in my situation.

And you covered exactly what I was wanting to hear, that the adaptive learning of the truck could be what is causing such a diffrence.

I might sound dumb here but ive never flashed my PCM, what do you need to do.

Thank you again Mike t. for your time, and merry chirstmas to you aswell,

Randy R.

P.S. I'll be out of town the next 2 weeks, but I will give you a call when I get back to talk to you alittle bit more in detail, and see on getting a max tuner on the way, post x-mas presant for me.

 

Hi Randy,

Thanks for your response..........

OK, so you sound like a seasoned bracket racer who obviously already knows the whole scoop on changing atmospheric data & how that affects engine power (especially in computer controlled vehicles!), so you don't need me telling you what you already know..........

Yes, this could well just be adaptive strategy at work here, assuming the atmospheric stuff either wasn't enough of a factor or was in your favor, etc. - adaptive can make a 1/2 second difference in a 3-ton truck - amazing & sometimes aggravating, too, eh?

"Flashing the PCM" simply means to reprogram it's onboard EEPROM chip (called "flash" memory, hence the term "flashing" being used instead of the more traditional term "reprogramming," but they both mean the same thing in this instance & regard) with a different program (tune).

For the 1996-2003 F-150's, that can easily be done with the Micro Tuner, it has 3 different performance tunes available for you to choose from. There are other ways to flash the PCM, for example Ford dealerships generally use their WDS (Worldwide Diagnostic System) setup, or it can also be done with a CARDaq (providing you can write the software you would need to use that unit) or an NGS Star Tester if you have one with the PCM flashing option, etc. In practical terms, the Superchips Micro Tuner is the easiest way to flash your PCM with a performance tune.

Glad to hear you steered clear of octane booster, and since your truck only has 30K miles on it, you can hold off the upstream O2 replacement until you have 50K miles, if you want to push them to the extreme limits (potentially) of their reasonable service life. O2 manufacturers say 30K miles, and I don't let mine stay in there even that long, in many cases, but I'm obviously a bit aggressive on O2 replacement, being a tuning nut. Realistically, for most daily drivers whose O2's don't get a shot of coolant or OB, a 30K-50K miles service life is reasonably attainable.

Have fun, Merry Christmas & talk to you soon!

 

I didnt mean anything by the post about weather, just wanted to let you know that there was most definatly a change for the better even though the truck wasnt showing it.

Thanks for the lesson on flashing, I need to get up todate on my terms, the only flashing I had ever down was in highschool and requiered my smarter friend (budweizer) to talk me into it.

I did turn down a MODIS lab scope/ scaner today which would have given me the ability to reflash the computer, but the money at this time is just to tight to get it.

I can swing the SuperChips programer though, and will be getting in contact with you after the holidays, I would like to talk with you alittle more indepth over the scanner first, as you stated in an early reply, so I look forward into both speaking with you, aswell as doing business with you.

Thanks again for all your time,

Randy R.

 

Hi Randy,

>>>I didnt mean anything by the post about weather, just wanted to let you know.... <<<<

Understood big guy, & that's how I took it - no problem at all - and my response was just saying that based on your knowledge of all that, then you obviously don't need me (or anyone else, for that matter) telling you what you already know - we're cool, my friend.

Sounds like an interesting piece of hardware you came across - we'll have to talk about that when you call.

Right now I'm still trying to get over the flu, it's got me pretty good - this is the first time in a week I've even been able to look at a computer, and the way I feel right now, I shouldn't have - so I won't be here long before it's back to bed!

Take care & talk to you after the New Year!