She wheelies!!!!

[lightningtroy]

Ok here is the simple version , As auto sho has posted and i agree with. factory maf sensors tend to be the most accurate,they are all a little diffrent but still work the best. one of the advantages is that the transfer functions are well know and their values are ARE PROVEN BY FORD TESTING. If you are screwing with factory transfer functions to get something else to work right you are throwing out all the resurch that ford did to make it work right in the first place! Think about it why does ford(and others) use gold plated pins on many of their low current circuts-because the values are that critical/sensitive! The transfer function is specific to the type of meter-not vehicle specific. I apply this same logic to other functions the ecm controls and preffer to leve as many of them alone as i can-again why thow all that resurch out the window. low and high slope values fall into this same catagory. they can and do affect how much fuel is delivered into the eng. but all you are still doing is adjusting pulse width. and now you have screwed with low/high slope tables. the ford ecm is smart if you adjust even just one thing it will figure it out and try to correct for it. has anyone ever put a adj. fuel press regulator on and cranked up the psi by just a couple of pounds? if you monitor the fuel trims and fuel pulse width you will see the ecm correct for it in a short time and you will be back right where you started from. i will be back to finish this post later

 

[Off Road SHO]

After he finishes working on The Other Woman....

Right?

:cry:

Tom

 

[AutoSHO]

The transfer function is specific to the type of meter-not vehicle specific. I apply this same logic to other functions the ecm controls and preffer to leve as many of them alone as i can-again why thow all that resurch out the window. low and high slope values fall into this same catagory. they can and do affect how much fuel is delivered into the eng. but all you are still doing is adjusting pulse width. and now you have screwed with low/high slope tables. the ford ecm is smart if you adjust even just one thing it will figure it out and try to correct for it.

By that logic, you're saying I should change injector sizes, but not change the injector slopes?

That would be *exactly* like changing the MAF and not changing the transfer function at the same time.

The computer corrects fuel trims in order to get the expected Air/Fuel ratio from a given MAF reading and load. Thus, when you tell it exactly how much flow teh injectors have, it does not have to correct anything - Because by correcting the Injector slope to exactly match the injectors in the car, you have allowed the car to be in a better state of tune. Instead of having it still apply fuel trims, and then adjusting the end pulsewidth (which is what it sounds like you're doing) where you will end up still losing the tune due to corrective fuel trims (KAMRF's).

It is very easy to dial in the injector slopes, especially if you have a wideband. All you have to do is turn off adaptive fueling and then adjust the slopes up or down until the numbers on your wideband match exactly with the commanded AFRs from the computer. At this point the computer is programmed to know *exactly* how much fuel the injectors flow, and it can now accomodate further changes with ease.

Chaning injector slope is the best way I have seen yet to correct fuel problems. It allows you to properly tune the car to avoid having leaning/richening issues as you are just driving down the road. It also makes it incredibly easy to tune a MAF response curve perfectly, and then you can adjust the commanded AFR's at part and WOT to make the most power possible, without any fear of running leaner or richer than it should.

 

[Shoaz]

Think about it why does ford(and others) use gold plated pins on many of their low current circuts-because the values are that critical/sensitive!

Actually, it's just to keep the contacts from corroding. Gold is almost as conductive as silver, but silver tarnishes. Since the MAF is one of the primary sensors that the computer uses and reading a low voltage due to corrosion-induced resistance on the pins would cause the engine to run lean, it's just a little extra insurance to keep the thing running safe.

 

[lightningtroy]

You're tuning a ford ecm so lets use ford terminology-ok. their is no such thing as KAMRF in ford terminology. their is KAMREF-LONG term fuel trim as the eng. operates in closed loop fuel control mode.KAM- keep alive memory.LAMBSE-SHORT term fuel trim as the engine operates in closed loop fuel control mode. both fuel trims operate together. You are shutting off adaptive strategy? why, how does you're car adjust for changing conditions? weather/altitude/aging how does you're ecm substitute learned value in case of a sensor failure? well simple, it cant. again you are disableing all the functions that made the ecm so great in the first place. we are way past the obvious of you stating that you should not recalculate for diffrent injectors i am not going to answer any more than that on that issue. you state that adjusting pw is a band aid? just what is it that you think you are changing when you adjust slopes-after manipulating ford tables the end result is a different pw. i am recomending you/ anyone leave all tables in closed loop alone, remember the ecm is CONSTANTLY MAKING ADJUSTMENTS AND AT TIMES THEY WILL NOT BE IDEAL. they are not supposed to be the ecm is using adaptive strategy to learn what the best values are, it can only learn these values if if it forces past ideal in both directions.

 

[lightningtroy]

Yes you are correct shoaz. this falls under the aging issue,

 

[AutoSHO]

You're tuning a ford ecm so lets use ford terminology-ok. their is no such thing as KAMRF in ford terminology. their is KAMREF-LONG term fuel trim as the eng. operates in closed loop fuel control mode.KAM- keep alive memory.LAMBSE-SHORT term fuel trim as the engine operates in closed loop fuel control mode. both fuel trims operate together. You are shutting off adaptive strategy? why, how does you're car adjust for changing conditions? weather/altitude/aging how does you're ecm substitute learned value in case of a sensor failure? well simple, it cant. again you are disableing all the functions that made the ecm so great in the first place. we are way past the obvious of you stating that you should not recalculate for diffrent injectors i am not going to answer any more than that on that issue. you state that adjusting pw is a band aid? just what is it that you think you are changing when you adjust slopes-after manipulating ford tables the end result is a different pw. i am recomending you/ anyone leave all tables in closed loop alone, remember the ecm is CONSTANTLY MAKING ADJUSTMENTS AND AT TIMES THEY WILL NOT BE IDEAL. they are not supposed to be the ecm is using adaptive strategy to learn what the best values are, it can only learn these values if if it forces past ideal in both directions.

I'm shutting off adaptive until I get the injector slopes very close - at that point I turn adaptive back on. Then I can watch the adaptive trims and further tweak the slopes until the KAMREF values are extremely small.

There is absolutely no reason not to adjust Closed-Loop and/or open loop fueling tables if you know what you're doing. Closed loop is pretty much all 14.64:1 anyways, but at higher load many cars from the factory are programmed overly rich, the SHO being no exception, commanding sub-11:1 AFRs at redline.

I would like to know, quite simply, what variable you are changing to alter, as you put it, pulsewidth. Commanded air/fuel ratio? Fuel multiplier? The computer calculates pulsewidth based on MAF signal and Injector Slopes, so what are you altering to change PW, as you keep stating?

Thanks for the spelling correction on KAMREF - but I'm well versed in what it is. Thats why it sounds like I know what I'm talking about when I use the terminology.

And, I don't think you've quite covered the injector size issue. What variable(s) do you change if you put larger injectors in a customer's vehicle?

 

[lightningtroy]

Injector pulse width. at low pulse width- 0-2 ms their is not enough time for voltage to build up and operate the injector under tha same scale as from 3ms and up this is the reason for low/high slope correction tables. anyone with a $5 noid light can see this. plug it in and you will see a dull light at idle=low voltage from such a short pw affecting fuel quantity delivered differently than when you rev it up and see a brighter light=more voltage and a different rate of fuel being delivered.

 

[Sho-Driver]

By that logic, you're saying I should change injector sizes, but not change the injector slopes?

That would be *exactly* like changing the MAF and not changing the transfer function at the same time.

Agreed! You also have to take into account, regardless of Ford's 'research', not all injectors flow the same I have data logged a completely stock SHO and found that the car still had to make fuel corrections. If it were tuned, as 'lightningtroy' says, it would not have to make more than 1% correction in either direction.

AutoSHO has hit the nail squarely on the head. By adjusting your injector slopes, your are telling your computer that there are larger or smaller injectors being used, even if stock. Changing injectors would be similar as to changing the MAF as you would have to start with slopes that are close and tune from there. If you put in a larger injector and do not change the slopes, you will run rather rich.

Ford testing/progamming is not all it is cracked up to be. If you have ever looked at many of the programs, they are not all that great. Take for instance the timing curve on the MTX SHO, have you seen that? It is as unsmooth as you can get. I am not saying everything they do is crap, but I have not been too impresssed.

 

[AutoSHO]

Injector pulse width. at low pulse width- 0-2 ms their is not enough time for voltage to build up and operate the injector under tha same scale as from 3ms and up this is the reason for low/high slope correction tables. anyone with a $5 noid light can see this. plug it in and you will see a dull light at idle=low voltage from such a short pw affecting fuel quantity delivered differently than when you rev it up and see a brighter light=more voltage and a different rate of fuel being delivered.

Read my question again -

What variable(s) are you changing in the computer programming in order to change injector pulsewidth?

 

[lightningtroy]

By the way autosho i enjoy speaking with you on this subject and at no time do i intend to offend FWIW. Dare i say this but i am in the bussiness of building/tuning cars it would not be wise bus. to "lay out all of how i do it" it has taken 18yrs of punisment to get to this point.at this point i would like to keep some things to myself for staying just a little ahead of the competition- it probably wont last long. i can tell you why you're afr go so rich at close to redline-their are two.

 

[AutoSHO]

I know exactly why my AFRs get so rich - keep the exhaust valves cool for one, and also because its safer for Ford to run more fuel through the motor than to chance it running lean.

I was just curious about what variables you change in the programming. I understand if you'd prefer to keep it to yourself, I was interested merely for the sake of discussion.

I am still curious, though - If you do not change injector slopes when you install higher flow rate injectors, how do you program the computer to adequately compensate for them? You could certainly reprogram the MAF curve to band-aid the problem, but then you'd end up with screwy load calculations, and a band-aid, what we're trying to avoid in the first place.

I've been very successful and pleased with my car while tuning it with the TwEECer. I can make it more responsive, idle smoother, get better fuel economy, and still produce more power, even with a completely stock motor. At this point, I'm not even sacrificing engine longevity. I can monitor spark advance as well as fueling (pulsewidth, LAMBSE, AFRs, KAMREFs, O2 voltages, MAF voltage, and so on...) realtime.

But, I've also always been a DIY kind of person. I always assume (so far, rightly so) that I know more about my car than any shop out there, and that I can do a better job of tuning it safely.

FWIW, you've been in business almost as long as I've been alive.

 

[Sho-Driver]

To be honest, there really are no secrets. There are forum dedicated to tuning these cars, as well as other Fords. The trick is learning what needs to be done and how to do it. Once you do that, what real secret is there? Obviously the codes have been cracked and available, and taught, to the general public.

 

[lightningtroy]

If you know "exactly" why ford programs so rich tell me why. you accused me of being bold in one of my first posts but you're last statement is a litte over the top dont you think?

 

[AutoSHO]

If you know "exactly" why ford programs so rich tell me why. you accused me of being bold in one of my first posts but you're last statement is a litte over the top dont you think?

Not really, it is pretty common practice in the automotive world to run the car richer than optimal (from the factory) to keep the engines from coming back as a warranty claim. Like I said above, running it richer keeps EGTs cooler, and accordingly, the exhaust valves.

Additionally, the engine is less likely to experience detonation with a richer mixture, which further enhances engine longevity.

Also, going back to the lower EGTs - Catalytic convertors will also live longer with lower EGTs.

The downsides to this practice are that it does impact power output marginally. There is some power to be gained by leaning out the AFR's to a more aggressive number, but this is of course at the risk of running a little higher EGTs and possible detonation as well. Careful tuning avoids all of this.

Additionally, the overly rich mixtures dilute the oil coating on the cylidner walls somewhat, promoting increased wear and, over time, some compression loss. This is a minor problem unless you are running extremely rich for a long period of time.

 

[lightningtroy]

You're probably right on the secrets issue but as you all know not many use all the info that is avail.- not even me but i used a lot more than most! in 20years do you think you just might look back and think man if i knew then what i know now.where do you think i am now? i have probably 1000's of auto based facts some interesting and some not so but one thing is for sure i have seen and tuned a few more combo's than any high school full of 18yr have

 

[lightningtroy]

I thought you had it there for a moment. good examples but the two reasons are........to prevent three way catalyst(twc) damage not from high egts but from to lean of afr. a twc job is to store oxygen during lean eng operation and then give up stored oxygen during rich conditions to burn up excessive hc. by running overly rich afr it floods the twc so that it cannot burn itself up. notice how many perf. cars have dead cats/ they have not considered this during tuning- i know you probably do not have cats but thats not the point. your wide band is not always accurate it can not account for exh. scavenging-and the fuel that comes with it. you must read plugs properly to performe sucsessfull tuning. heres a secret n/a .888v@wot is ideal o2v.

 

[Sho-Driver]

i have seen and tuned a few more combo's than any high school full of 18yr have

I am not totally sure I understand what you said there, but I have the gist of it. If you are implying that we are some high school fools that have no experience, you are off on your presumption.

to prevent three way catalyst(twc) damage not from high egts but from to lean of afr

High EGT's, coincidentally, can be a major effect of a lean AFR. In which case, you have proven AutoSHO to be correct. More fuel will not only keep it cooler, but it will insure there is enough fuel for the amount of air that is taken in. We could also go in to detonation at this point, but I have already posted about this in another thread, also providing a link to a very informative site. Yes, more fuel will burn up catalytic converters as that is what they do, burn more unburned fuel.


The wide band has proven to be EXTREMELY valuable and can handle exhaust scavenging just fine. Most wide bands are only run on 1 bank (3 cylinders in my case) so you can only really view what half of the motor is doing. Some have thought about adding two sensors and switching between them, but with real-time data logging, one can view both cylinders narrow band sensors, KAMREF, LAMBSE, etc... You are correct with reading plugs for tuning, especially for initial tuning so that you do not blow the motor up. The wide band has actually proven to be accurate to 0.1AFR, which is good enough!!

heres a secret n/a .888v@wot is ideal o2v.

That's no secret.

 

[lightningtroy]

Hey Tom i just made a second gear pull to 6,500 you're car makes 5.9 pounds of boost at the intake just before the runners-after the intercooler. On my lab scope, calibrated just before i tested booooooost! coolant temp is good now and the belt stays on . The mufflers should be in on monday and will take a day or two to install

 

[lightningtroy]

By the way autosho you are completly wrong on all of you're statements,you have a bad attitude and no matter what i say you would claim it to be wrong. nuff said