Originally Posted by Johnny Langton

I don't know where you're getting your info,but the MAF isn't setup for pure performance-it's setup to measure airflow-plain and simple. It does nothing else.The PCM knows the transfer function of air mass through the MAF in relation to the output to the PCM from the MAF.It also knows the injector's fuel flow rate,and fuel pressure across the injector. The PCM then calculates the mass of air(whether it's at -5000 or +20000 feet and calculates the amount of fuel to inject based on this data). There is a spark table in the PCM called the MBT table(max brake torque table),and it's setup on the engine dyno. These are the spark values that makes the most torque at a given RPM and load. Beyond that value there is no gain,or a loss of power due to too much spark advance. The PCM will command MBT or close to it unless the Max Allowed Spark table or the Borderline Knock table are less than the MBT table for a given vehicle and fuel configuration. Then you have all of the inputs that add or take away spark(the spark modifiers),and the PCM uses all of this data to calculate the final spark value.
Basically..it's gonna give the engine the optimal spark advance value for the given conditions and airflow rate,so ther's no need for special "high altitude" calibration to make more power when in high altitudes.

JL

Originally Posted by swann79

Why your 5.0 does better over them passes is beyond me... I have had the same experiences and found that the 4.6 did better than 5.0, 5.4 did better than 5.8. My first question would be what kind of gears are in these trucks? If that 5.0 is lower geared than the 5.4 then that would probably explain it.

All of my previous trucks were geared in the 3.50-3.73 range. My father-in-law has a 5.0 in a '96 F-150, he traded in a '97 4.6 for it... he wishes he'd kept the '97, cuz the 5.0 is an absolute dog in the mountain passes, especially when towing.

For the record, the 3v 5.4 I had in my '04 crew even outpulled my old 390 in the mountain passes.

Originally Posted by kaboom10

XFI FI from F.A.S.T. is made solely for performance. You won't see many daily drivers. We used to just listen for spark knock as we would add spark advance till we heard it. This is the way GM did it. That must be the spark curve they put in the PCM. Thanx again. They wouldn't tell you any more info than it took to do the job.

Originally Posted by Johnny Langton

Ford actually uses special spark plugs with pressure transducers built into them for measuring cylinder pressure when they're setting up the spark tables. The Engineers add timing into the engine while on the dyno in a steady state loaded condition,and make note of when cylinder pressure spikes due to detonation or preignition. They can dial in a perfect timing curve that way,and also use that to determine the right spark curves for a particular engine with different octane fuels.
JL

Originally Posted by kaboom10

When I find that powdered metal technology is up even with tried forhing design I might change my mind.

Originally Posted by 2000BLK54

Apparently what you know about powder metallurgy is about 15 years out of date if that's what you believe. PM process forgings can be designed to do things that conventional forgings can only dream of. As a matter of fact there is a company that produces rods for the SBC/BBC market currently using PM and they are stronger and more consistent than even some of the best forged rods available.

Originally Posted by 2000BLK54

GM Gen III and Gen IV smallblocks use PM rods and main caps and PM components are used pretty much across the board whether import or domestic. The alloying constituents can be in much higher concentrations than what can be achieved practically with standard forging. Look at the knife industry, CPM steels started a revolution in high end knives due to the quality and strength of the metals.

Originally Posted by rkymtnman30

The 5.4l is good for a flatlander as I see it my brother has a '02 150 for bopping around town and a daily driver not one complaint and in the high country no load okay throw a camp trailer and gear behind it you better not be in any sort of hurry and hope you brought a lunch. My 86 5.0l will run it to death side for side and my 91 351W runs circles around them both. But as always if the truck and motor fit your needs then it is the truck for you.

Originally Posted by Trevor1

my dad's 2001 screw 4x4 with a 5.4 will kill my 1993 f150 scab 4x4 with a 5.8l, the 5.8 will turn no rpm's and just as it starts pulling it runs out of breath and shifts, 5.8 will not get out of its own way with a 2000 pound trailer hooked to it

Originally Posted by 1991F150lvr

Hey guys, my dad and i have been talking about the 5.4L engines problems and were both convinced its not a good engine. A plastic intake manifold on the new ones, WTF? My dad has one in his 2000 F250 service truck and to him its a piece of crap that drinks gas and has no low end torque. despite its an OHC engine it doesnt seem to be very efficient also. and he also told me about the spark plug problem that happened to the 5.4L in a friends truck. something about the threads messing up and the spark plug falling into the engine.

I just want to know what you guys think of the 5.4L, because most of you might drive one everyday. if you can shed some light on my negative views of the 5.4L go right ahead. Feel free to share your experiences with this particular engine. peace out. -Mat

Originally Posted by 2000BLK54

The PM rods were a carry over from evolutionary work done on the LT4 before it was scrapped in favor of a clean sheet build that would become the LS1.

To quote from part of an article talking about PM rods...

Originally Posted by 1991F150lvr

Im sure that the 5.4L works great for all of you. I have heard of 97-03 ford trucks running as many as 150000 miles on them with no major problems, but to me older V8s will last longer, because they are simpler and low tech.
Do you have any data to back up your unsubstantiated claim?

the more simpler the engine design, the less things that can go wrong. For example we have a '98 dodge caravan with a 3.3L V6 that has 189,000 miles on it and still runs fine. the dodge 3.3L is a simple low tech pushrod engine. I see many caravans still on the road today that seem to run forever.
Comparing the 3.3 V6 to a modular motor is like comparing apples to gorillas

I dont know everything about cars, i am just thinking logically. the more simple a desigh is, the more efficient it is. new trucks are computer controlled with all kinds of sensors, and computers and crap. where as my old 79 ford 5.0 had none of that hi tech crap and took more abuse than any new 5.4L could stand.
To a point. With a computer controlled motor you will have better mileage, power and driveability in a variety of conditions than a carbed motor. There is a reason things are more high tech. You admitted to not having driven a 5.4 truck and yet you continue to make claims about the motor without and first hand experience.

The guy who owned it before me drove it hard, i drove it hard upon occasion, and the guy i sold it to still drives it today, and that 79 probably had more than 200k when i got it. is your 5.4L still gonna be on the road when its 30 years old? I doubt it, a slim chance.
Yup, mine sure will be. Again, you are making claims without any backup.

i dont mean to be cold and i dont have any beef with anyone on here, im just expressing my opinion. I am a very analytical person, i just believe logic makes the most sense in some cases.
You claim to be analytical and yet you continue to throw out unverified claims and opinions.

New trucks arent for everyone, and im one of those people. im just not sold on these new trucks. You have to understand where i come from, i thought my current '91 f150 was a big step up from my previous '79 F150. anyways sorry if i offended anyone, and thanks for reading. hope to hear from ya.