Mike you made this post in the Lightning Forum but never answered my post, Here is what you posted and I also Copy and paste my post underneath yours



Wow, Mike excellent post and thanks for taking the time to explain this to us all. I have a few questions reguarding some things you said, Im not looking to argue, Im looking to learn here.


I ran a 6lb overdrive pulley on my Lightning for over 12,000 Miles and 100's of 1/4 mile passes. My first few passes down the track, resulted in Pegging the Mass Air Meter. This was only happening in 1st gear right before the truck shifted. On either my 3rd or 4th pass down the track the problem went away. Like I said, since that night I put over 12,000 miles and 100 passes on the truck. The truck ran in every condition imaginable, 115 degree Dry Heat(Las vegas),100 Degree Humid Heat(Houston), -15 Degree Cold@1000ft Elevation(Canada) to even -25 Degree Cold@5000ft(Montanna) After the 1st time at the track I never ran into this problem again, Did the PCM relearn itself or what ? I know the mass air initally being pegged because I had a Scanner to monitor things. I also know that after that day at the track the Mass air was never was pegged again, verified again with scan tool. I also verified the A/F ratio on 3 different occasions, Stock was 10.9:1 and 6lb pulley was 12.3:1 on a wideband. Mike I dont mean to put you on the spot but you are the 1st tuner Ive seen to offer information in these type posts. I know several people who have posted in the Lightning Forums who run 4 or 6lb pulleys and no chips and had no problems. You have added Valuable information to this post and I hope you can add more by answering my questions.

Thanks

 

Mike is the greatest aint he.

 

Hi BigFan,

Thanks for your post - and please don't take this the wrong way, but it's only fair to let you know how "over it" I am of some of the rationalizations claiming that no custom tuning is needed to run raised boost safely on the factory supercharged 5.4's or Cobra 4.6's - it's *not* safe on the unaltered factory tune, regardless of how long anyone says they have gotten away with it. And please don't take that personally - I'm sure you're a sharp fellow!

That's why I never responded to the endless litany of those kinds of threads in that section............

I have not seen any Lightning (that wasn’t down on power, I should say) that didn't run out of MAF voltage running on the factory program (which allows only 4.78 of the physical 5.0 volt range of the MAF) with a 6 PSI pulley making a 1/4 mile pass.

There might perhaps be some combination/set of atmospheric conditions that might allow that to happen, but I haven't seen it in any of my data logs.

Best-case, they usually peak right at about 4500 rpm in 3rd this is WOT, of course) - I have seen conditions in which they could run all the way thru 1st & 2nd gears (where load is far lighter), and then not have a problem until hitting about 4500 rpm in 3rd gear @ WOT - but I have not seen one (that is, that wasn't down on power) NOT run out of MAF voltage on the stock tune with a 6 PSI pulley - nor will I *ever* agree with doing that.

Unfortunately, I simply do not have time to carry on a detailed discussion on *anything* via typing - and I can only imagine what's come out of the woodwork since I made that post, which was discussing a '99 or '00 L running a 90mm MAF *AND* a raised boost pulley on the factory tune, that was the original topic.

However, if you feel you have actual data logs that show you running a 6 PSI pulley (and I can see that it's a raised-boost pulley in the load data, if that is provided) on the stock factory program and not ever hitting 4.78 volts @ WOT, I'd love to see it......

I'm in Atlanta for a dyno day session with the guys from Superchips Custom Tuning, so I won't be back in the office until Tuesday for about half that day, then by Wednesday I should have normal availability - if you'd like to give me a call, I'll take a look at your data & go over this with you in some proper detail if you like, Ill be happy to.

Thanks for your post BF, & hope to speak with you soon!

 

Mike, I dont have any Actual files to email or discuss with you. Im only listing the data, I recall seeing on the NGS when I made my passes. Im telling you on my truck the mass air meter did peg the 1st few passes I made, this was done on the 1-2 shift. I agree and can see why you avoided the post where I pulled this information from, it did turn into a bunch of people giving opinion that it was safe to run a pulley without a chip, mine was different. I listed factual information and asked valid questions, it wasnt just a opinion that it was safe because my truck ran. It was information I saw on a dyno that monitored a/f ratio, information I saw on a NGS that monitored anything I wanted but more specific mass air voltage. Im asking Valid questions here, Im not just stating opinions. I know I dont know more than you because Im no tuner, but I do know a few basics. Correct me if Im wrong here, when you peg the mass air meter the computer will dump extra fuel to prevent going lean, correct ? Pegging a mass air meter wont result in a lean condition, it defaults to dumping extra fuel. Im sure it does other things but Im unsure of every single thing it might do. You say that every truck will peg the mass air meter, a driver will know when his mass air meter is pegged, the truck falls flat on its face and doesnt make anymore power. Again why did my truck correct itself after the 3 passes ? Was this the a adaptive strategy of the stock PCM ? Enjoy Atlanta, Im on the waiting list for the SCT stuff when it is released to the public, Im waiting on the flasher version. Jerry, Chris and Dave have really come up with some very cool software, I just hope I dont blow my truck up. I would be happy to monitor the Mass air voltage for you but effective today my truck is uninsured, the Snow is starting to fly

Thanks

 

Hi BigFan,

Ahh, I see - so you logged using an NGS, thus you don't have any kind of output file you can just send to us - understood.

What I would suggest for future reference is to make sure you *record* all that data logged with the NGS after each pass - just scroll thru the NGS screens and write the data down - write down every data stream logged, what it was at every rpm the NGS was able to sample, so you don't have to operate from memory - just scroll thru the NGS screens & jot it down in a notebook, or what have you, etc., so you have access to it later on/permanently. Then after you get back home, you can just make up a quickie spreadsheet with engine rpm on the X axis (the bottom row of the spreadsheet), and then all the data from each sensor output each time they were sampled during each run along the Y axis, and then you'll have a very nice chart of data matched to engine rpms, for each pass - that data in invaluable, and since you have access to an NGS, this is easy to do - just FYI.

Here's the bottom line: once the MAF hits a certain # of A/D counts (about 980), the PCM will switch over into operating off of a "failed MAF" table - now this generally does prevent an immediate gross loss of control, but the PCM isn't responding to load in the normal/preferred manner any more as it's not using those same tables - it's using different tables, in that scenario it will default over to using the failed MAF table, and that's no way to run. Also, you're down on power compared to what you'd make with a proper tune. The bottom line is it's just not a desirable or smart thing to do, and the cost of a proper tune is nothing to anyone that can afford to own & modify a Lightning.

And then there's the load tables...........just using a 4 PSI pulley increases calculated load (ve) by well over 40%-typically 45%-47% is what we've seen just on the dyno, where you're not under the same load as when the vehicle is actually being driven the driven load is always greater than what you see on the typical inertia dyno.

Also, as I pointed out in my last post, I'm not talking about when the *MAF* itself physically peaks - and I think *that* is the specific point you may be missing........... I'm talking about when running on the factory program, which only allows 4.78 volts of the 5.0 volt MAF range, with a 6 PSI pulley - you'll run out of MAF voltage **in the program** - NOT in the physical meter itself - heck, the 90mm MAF will generally support 600+ HP @ flywheel, over 500 hp rear wheel - but that doesn't automatically give you 5.0 volts of MAF range in the program, the only way you get *that* is with a tune - not on the stock program.

When you run out of voltage range **in the program,** which is what I'm talking about, then the PCM thinks the MAF has failed (even though the MAF itself has more range), and defaults over to the failed MAF table. Ever wonder why you never saw anything more than 4.78 volts from the logging the MAF data with the NGS? Bingo! That's what I'm talking about, the factory limitation on the MAF voltage **in the program**. That's the same for virtually all Ford MAF vehicles, they basically all have that 4.78 volt limitation in the factory program, and that has to be altered to get the full 5.0 volt range of the physical MAF itself - remember, there's the MAF itself, and then there's the *program*, and each have their own limitations/parameters - in the stock Ford programs, it's generally limited to 4.78 volts, regardless of the fact that the MAF itself has a full 5.0 volt range.

Only when the MAF *itself* physically peaks it's 5.0 volt range will the motor actually lay down like you're describing - and that is a very simple matter of course, where you have literally run out of physical MAF - then you must upgrade the MAF itself - that is *not* what I'm talking about here at all - that actually has nothing to do with what I'm talking about.

Using a 6 PSI pulley on the factory program you're running out of MAF voltage **in the factory program** which only allows 4.78 volts - and there is a significant difference in CFM's between 4.78 & 5.0 volts with the Lightning's 90mm MAF. In any "healthy" Lightning running a 4 PSI pulley and any intake kit on the factory program, they always run out of MAF voltage in the program in our experience, in that configuration they hit 4.78 volts usually by somewhere between 4000-4400 rpm @ WOT in 3rd gear & then the PCM defaults over to using the failed MAF table. The failed MAF table generally prevents a gross loss of control over the motor, but that is *not* a proper tune, nor is it "OK," despite a few people (or 50 people) saying they've been getting away with it.

So what you're actually doing in this scenario is finishing up the top-end charge in the 1/4 mile - most of the time you're in 3rd gear, actually - running on the failed MAF table, and this is @ WOT - not the preferred method of operating, and it's something I'd *never* advise anyone to do.

At any rate, this is my last post here on this as I just don't have any more time to spend typing on this topic. If you'd like to go over this any further, feel free to give me a call.

Good luck!