Where am I getting it from?

1. Ravez burnt his piston running at higher rpm's, car running lean it appears.
2. EJ ATI is running lean/detonation at about 6000rpm and he stated he is now fearful to run it above 5000rpm.
3. What you consider tuninability I consider a design flaw. What good is the ability to "tune" if guys that are trying to get it correct keep running too rich at low rpm and too lean at high rpm?

If Nissan released a motor that was doing this, people would demand it would be fixed or recalled. Heck, a person got their Z lemon lawed over window streaks last week. There is no way it is acceptable that a SC A/F mixture is doing what is happening right now on an ATI. Both of the guys above are trying to get it set correctly yet it is not working. I am not saying the ATI is not fixable but to say it is does not have a issue that needs to be corrected is not looking at the data being posted.

If you think the ATI can be tuned properly then maybe you can post the procedure for everyone here and the tuners that have not been able to do it with all these installs. I am sure they would love to know how to do it correctly.

 

Don't forget he also lost his girl friend

 

I'm running in the range of 10.5 to 11.4 all the way through the rpm range. At redline, its 11.4. The fluctuation is due to the method of fuel control, and it could be smoother if a different method was used. But, the a/f ratio is safe all the way through. Yeah, I'm losing a little power since its not tuned right up to the edge of safe a/f ratios. Some people are tuned on the edge, and get more power. But when something is off the slightest bit, they don't have much of a cushion before things start getting bad. Note that I'm just telling you how mine is tuned, and I have no idea what other guys are tuning for with regards to a/f ratio.

In response to your numbered items:

1. How do you, or how does he know this? It could have happened anywhere in the rpm range. Did he have a wideband o2 sensor on it to monitor the a/f ratios, and actually see that it was lean at high rpms? Could just as easily have happened at 4k rpms right after a shift.

2. I don't know about EJ's situation, so no comment there.

3. The efmu has adjustments to address exactly what you are talking about. If its too rich at low rpms, then you dial back the fuel in the rpm range where that occurs. Likewise at high rpms if its running lean. How is this a design flaw? If anything, you might be able to point at ATI and say their documentation of tuning the efmu sucks. But the thing does work once you know how to set it up.

The only reason I'm even saying anything is because there is a lot of misinformation on this board about how certain things work. People just love to bash ATI and they don't even know why they're doing it because the reasons they present are bogus. I'm not saying that the ATI kit is flawless, or that you absolutely should buy it over something else.

Another thing to consider is that running forced induction with "safe" a/f ratios doesn't necessarily mean you won't have problems. Timing is another major factor, and this is where my concern with the ATI kit is. Vortech is going a good route with their boost timing retard, and this is something that I might look into using on my car. Theoretically, you shouldn't need it since the ATI is intercooled. But, we're running a high compression engine with n/a timing maps, so it really wouldn't hurt to tone it down a bit.

 

Gary, there are certain people here on this board that are convinced that the Procharger is the worst thing designed and built ever. You are not going to change their minds. Most of the time you post information, I guarantee that they're not reading it thoroughly because I've tried to dispell misinformation over and over again. 1 week later the exact same topic that I already clarified pops up by the same people.

I posted the method months ago. You can view the proper way to do it here.

http://www.350zfrenzy.com/forum/show...&threadid=2342

 

Gary & Jesse:

1. Thanks for the replies and info.

2. Jesse: I assume since you quoted me in your reply, you are refering to me as being someone that is convinced that the Procharger is the "worst thing designed and built ever" and that I am " not going to change my mind". Actually, not is not accurate. I do like many aspects of the procharger. I feel it gives great hp, like the intercooler, in fact love evrything about it but I am fearful of the people that have had it installed and either having problems (engine failure) or as in EJ's case, detonation and fearing engine damage. I am in the market for a FI system and keeping an open mind to all products. I still think the ATI kit could be a trouble free kit with certain areas getting improvement.

I do believe you and I have a different level of what we think is acceptable for a kit being reliable. Basically, if I purchase a kit from a company and then take it to a certified tuner they recommend, I feel I should be able to drive it without major problems and I a should not have to have a mechanical engineering degree to make sure it works properly. Does that mean I should be able to abuse it and expect no problems, no!

Most people that have concerns simply avoid the product. I am vocal about the issues related to this product because I do like many apsects of it. Actually, I wanted to buy one right away (it was my first choice when considering performance and cost compared to Greddy TT etc). Being careful, I promised myself to wait 6 months before buying it to see how reliable it would be. This is when i started worrying about it, as problems began to appear.

You have done a good job in posting some of the details of tuning above. I find it very informative. It is too bad ATI is not doing those things privately or or on forums to raise the awareness of how to tune their products or making sure their reccommended tuners know and apply correct methods of tuning to insure optimal operation of their products.

I am not trying to slam owners of ATI products nor ATI specifically except for being critical of problems occuring with customers and them being addressed and corrected. I am just as critical of Nissan if they do not fix their design problems ie tire feathering and Bose stereo.

Will I change my mind? When I see the problems being solved and I see ATI being more concerned with trying to help their customers within reason to have a SC kit that operates within the purpose it was designed to be used, then I will change my mind.

I do not claim to be the God of FI systems. All I really know is if a product performs well, is reasonably reliable, and fair service is given when a problem arises, then I will feel it is a good product.

An owner of a new car should not have to have an engineering degree to own a car, nor should an owner of a SC kit. That is what we are paying for in a kit, engineers to design a product that works properly. If I wanted to design and build my own SC, I would not need to buy a kit and could possibly save myself some money.

FYI, I was the guy that got SportZ magazine to test and compare all SC, TT kits on cars. I made sure STI, Stillen, and other kits are going to be in this future test. To say I am anti ATI is not fair IMO. If I see pros or cons of any system, I point them out. All opinions and information should be availible to us. I am happy you reply and counter what I say. This allows all of us to weigh what we feel is accurate. If what I post is inaccurate, the facts will prove them to be and I accept that.

I just hope we can always debate the merits of products without getting into personal attacks. We can disagree yet still raise awareness. I just dont want to see a thread get ruined by personal attacks like some other threads have become. Neither of us have done that thank goodness even though we do not agree on some issues here. All of us want the best products for our cars so we all have common goals.

3. I read your post on tuning and if you dont mind, I am going to paste it to this thread. I learned some things by it, hopefully others will to.

Jeff

 

I pasted below what Jesse had a link to above. This is a really informative replyy to questions Jesse asked a tuner. Enjoy....

Reply from Aeromotive regarding DFMU operation, calibration and tuning
I asked Brett at Aeromotive to provide a primer for those users who are not technically savvy. Here was his response.

--------------------------------------------------------

Jesse,



We spoke by phone regarding the Aeromotive Digital FMU (DFMU) P/N 16303, it’s function and application. You requested that I answer those questions in written form in order that you could share the information with others whom you knew had similar interests. Your questions were:



1.) What are the various adjustments/settings and their purpose?

2.) Could there be variation between the scalar set-points from one box to the next, if all were calibrated to the same psi standard?

3.) What would be the best way to initially calibrate the DFMU?

4.) What would be the best tuning approach for the “average” user?



Before addressing those aspects, it may be necessary to cover a few basics for the “average” person before digging too deep into the specifics. In order to best apply the DFMU, it would be necessary to understand it’s purpose, which is the same as it’s predecessor the FMU. In my experience, few enthusiasts have any idea what an FMU really is, how one works or why it’s used to begin with. So, we’ll start there.



FMU stands for Fuel Management Unit. It was first created and applied to EFI engines in the early centrifugal blower (and then turbo kit) days, making it possible to mass market bolt on, forced induction kits at affordable prices. Without the FMU, it’s very doubtful that today’ aftermarket performance industry would thrive as it does now. The alternative, adding larger fuel injectors and recalibrated ECU’s or other components, is just to complex and expensive for an entry level supercharger or turbo kit.



The FMU’s purpose, is to raise fuel pressure with boost on a ratio GREATER than 1:1, in order to make up for a fuel injector that has reached 100% duty cycle, preventing the engine from running out of fuel and detonating. By forcing the delta fuel pressure higher (difference between the injector inlet at the rail and the injector outlet at the runner), a small injector can be made to act like a bigger one, to a point.



The original FMU was a pure mechanical device, created to work on the same principle as the fuel pressure regulator, by creating pressure with a restriction of the fuel return line. It has been an effective but coarse tuning tool at best. Due to it’s linear response to boost, forcing fuel pressure higher in direct proportion to rising boost pressure, it offers no means to tailor the fuel delivery to the actual injector duty cycle and engine fuel requirements. Normally, a properly adjusted mechanical FMU produces VERY rich A/F ratios in the midrange (before the injector is actually too small, i.e. at 100% duty cycle) in order to be rich enough at the top of the gear (when the injector is definitely too small). Many are those who attempted to adjust the FMU to clean up the midrange, only to find a lean condition and engine damage on top. With the Aeromotive Digital FMU, complete tuning of the fuel curve is now possible, however caution must be exercised when adjustments are made or engine damage can result. Additional tuning information will be provided below.



The demise of the FMU has been the result of changing fuel system design, where emission control (evaporative emissions created by warming fuel as it flows through the fuel rails and back to the tank) has superceded fuel system performance as a priority. With today’s “returnless” or “dead-head” fuel systems, there is no place to insert an FMU. This seemingly small thing, the lack of a return line, has created a real barrier to making entry level forced induction available and affordable for the modern day, OBD II, EFI automobile. This is where the Aeromotive’ “Digital Fuel Management Unit” or “DFMU” comes into the picture.



How the DFMU works can be difficult to grasp but, basically it is a boost sensing fuel pump controller. It runs a second fuel pump, installed after the stock, in-tank fuel pump and regulator. This second fuel pump is plumbed so that during normal, non-boost driving conditions, it is off and fuel from the stock pump simply flows around it, with stock fuel pressure in the rail and stock fuel delivery to the engine. The DFMU control unit has a boost sensing line that connects to an internal pressure transducer, when boost is sensed, the second fuel pump turns on. Because there is no regulator after the second pump, as there is after the first, albeit in the tank, when the second pump starts it forces fuel into the rail at a rate that is determined by how fast the second pump turns. The speed of this pump is determined by the slider settings on the face of the DFMU control box. Positioning the slider at the lowest position runs the pump at the slowest possible speed, building the least amount of additional fuel pressure in the rail. As the slider is moved higher, progressively more fuel pump speed is created, building more pressure in the fuel rail, and delivering more fuel into the cylinder.



Setting up the DFMU for proper engine fueling requires several steps. The first is to establish a correct scale. By this, it is meant that all 5 sliders will be available for tuning within the boost range of the application. For example, some kits will make 5 PSI of boost, some 10 PSI and others even 15 PSI (15 PSI would be pushing the practicality of an FMU or DFMU by the way). With 5 sliders on the box, the ideal scale calibration would involve dividing the total boost expected by 5, then multiplying that by 4, then setting the scalar adjustment so that the 5 slider was activated at that boost point. For example, an 8 PSI kit would calculate as follows:

A.) 8 PSI divided by 5 bands equals 1.6 PSI per band.

B.) 1.6 PSI multiplied by 4 bands equals 6.4 PSI.

C.) The 5th band should then activate at 6.4 PSI for an 8 PSI kit.



The scalar adjustment can be made with a reliable, regulated pressure source (CO2 bottle with low pressure regulator works well). The procedure is to apply the calculated pressure from above to the boost reference port. Then, adjust the scalar pot (silver, arrow shaped pot in the lower left corner of the DFMU) so that the light over band 5 just turns on at that pressure. This is the process used by ATI Pro-Charger when the boxes are pre-calibrated to a safe tune at the factory. Note: the scale engraved on the face of the DFMU, around the scalar pot, is not calibrated directly to boost, it is just graduated for a reference. The pots themselves are set on the board beneath in the same fashion for each unit. However, particular or exact alignment from board to the next, in order to ensure that the arrow would point to the exact same scale line, at the exact same pressure on every unit built, is not an assembly criteria. Do not expect that, from one unit to the next, there will be an exact correlation between the position of the arrow and the actual calibration of the scale to a certain PSI of boost.



Once the scalar adjustment has been made, careful tuning can commence. The best approach for the inexperienced tuner (read someone without a wide-band air/fuel meter, a good spark plug magnifier and the knowledge to interpret both) is to start with the highest possible settings, and work down from there.



Warning: Incorrect adjustment of DFMU scale and individual sliders will result in improper air/fuel ratios in the cylinder combustion chamber. Air/Fuel ratios that are too lean for the engine’ compression ratio, boost level, fuel octane and timing advance WILL RESULT IN ENGINE DAMAGE, WITH POSSIBLE MAJOR COMPONENT FAILURE. Proceed with caution, make small changes and watch carefully for signs of detonation, before it gets out of hand.



By adjusting all sliders to the top of the scale, the richest possible air/fuel ratio will be created. With an application where no base tune is available from the supercharger or turbo kit manufacture, this is the best starting point. The engine should be driven gradually into boost, where the fuel pressure is driven too high at the first slider. Normally, engine acceleration will halt. Gradually bring the slider down until enough additional RPM and boost will light the next slider. Gradually bring this slider down until the same occurs with the next and then the next, until full boost is achieved. At this point, a full rich, acceleration fuel curve is programmed into the DFMU. NOTE: any changes of the scalar setting after sliders have been adjusted will require a recalibration of all sliders, once the scale is set, further adjustments to it are discouraged unless absolutely necessary.



From here, it is advised that professional assistance be acquired if further power (read leaner air/fuel ratios) are desired. The installation of a wide band air/fuel ratio meter, testing on the dyno where careful monitoring of same can occur, along with periodic inspection of ALL spark plugs is conducted. This is the procedure utilized when tuning any high performance racing engine, follow it for best results.



Any questions about the DFMU or it’s use may be directed to me at the phone or e-mail address below. Good luck and thanks for choosing Aeromotive products!



Brett Clow

Aeromotive Tech Dept

5400 Merriam Dr.

Merriam, KS 66203

PH: 913-647-7300 ext 109

FX: 913-647-7207

 

I posted 2 answers I found on the Vortec website related to issues we are discussing. The website is http://www.vortechsuperchargers.com/support/faq.html

Here are the 2 questions/answers I thought added a little bit to our discussion:

30. What is detonation?
Detonation is the sudden increase in cylinder pressure caused by pre-ignition in the combustion chamber. This happens as the flame front moves from the ignition point, pressure waves in the combustion chamber crash into the piston or cylinder walls. This results in the sound known as knock or ping. This condition is strongly influenced by fuel-octane rating, ignition timing, and compression ratio as well as boost levels.

31. What would cause my engine to detonate at high RPM?
Detonation at high engine RPM is generally caused by a lack of fuel or improper ignition timing advance setting. Other causes of detonation can be high engine temperature, excessive supercharger discharge temperature, low octane fuel, bad spark plugs or excessive boost.

Jesse and others, assuming the answer to #31 above is correct, which of these causes would you think is producing detonation on EJ's car at higher rpm's?

 

I'd like to know more about EJ's problems. I don't get a lot of time to read the boards any more, so I haven't come across anything. Is there a thread where his problems are described?

It really could be anything listed in the #31 answer from the Vortech faq. Without a lot more information, there is no way you can even make a guess about the cause of his detonation.

 

i can summarize them for you real quick like.......i got my car tuned......i did a burnout......my #6 spark plug died on me.....it was closed when the tech took it out......spark plug replaced, i went back to my tuner, the car would not tune rich enough at anything above 6Krpms......even with the slider all the way up.......after talking to a lot of people about this......i've come to the conclusion that it's in the timing.......i'm just thanking God my engine didn't blow like the others.......the tech looked inside the cylinder and saw no damage in there

 

i've heard of this before. is there any way to tune the fmu above 6K?

 

not on mine, not without detonation......the only way i can get my system right is with timing control......i'm convinced of this

 

I don't have an answer for EJ's problems. If I had to make a SWAG, I'd say that the scale dial is set improperly and doesn't allow tuning at higher boost levels. I have not seen EJ's system though so I could be totally wrong.

If the dial is set too low, the fuel increase will come on too early and not allow any more adjustments at higher boost levels. It really has nothing to do with the RPM, other than how much boost the SC is creating.

Given EJ's description of the problem it doesn't sound like a timing issue because he said he couldn't tune it rich enough. If I were him I'd have the scale setting changed.

Once again, without actually seeing the system this is just a guess.

 

i guess ati needs to be notified of this before more engines blow.

 

if its in the timing, get an MSD ignition and get a timing reatrd dial, Ive used it many times on cars where I spray and it works like a champ for fine tuning the retard on the timing., but i think jesssenglish is right on, the ATI FMU needs to come on later, you dont need that much more fuel at low boost or low RPMs the scale needs to be bumped up.

 

ok, now I'm curious. What is your scale setting?

 

EJ -

You had the car tuned before the spark plug problem. Did you any problem with the tune then? It doesn't make sense that it would work before the problem, but afterwards you can't get enough fuel above 6k. Something had to change. Without more detail, I have to go with the consensus that the scale setting is off on your fmu. Have you verified that the scale setting is correct using some type of metered air supply?

I would not just set it and assume its right by the numbers on the fmu casing. You must check it to make sure the last band is operational at the right boost level.

 

Or, are you sure youre not getting sparl blowout? if you replaced a spark plug did you go one step cooler and close the gap up a bit? Is it just losing power or are you getting ping and detonation?? Ive seen it numerous time where people tune and tune and tune, and it turns out to be plug blowout.

 

It was doing the same thing on my initial dyno......but we thought it might have been because of a leaking intercooler hose......the hose was fixed on the second dyno, and the results were the same, detonation at 6K and up.......with the colder copper plugs that ATI recommends, with a reduced gap.......i'm getting crackling detonation

 

EJ,

Do you know for SURE that the last slider is activating? Could it be possible that your "scalar" adjustment is set too high, and therefore @ 7psi the unit is still using the second to last slider?

Here's the part I'm thinking of (I changed the example for the Z's 7 psi kit)
_____________________________________________

Setting up the DFMU for proper engine fueling requires several steps. The first is to establish a correct scale. By this, it is meant that all 5 sliders will be available for tuning within the boost range of the application. For example, some kits will make 5 PSI of boost, some 10 PSI and others even 15 PSI (15 PSI would be pushing the practicality of an FMU or DFMU by the way). With 5 sliders on the box, the ideal scale calibration would involve dividing the total boost expected by 5, then multiplying that by 4, then setting the scalar adjustment so that the 5 slider was activated at that boost point. For example, an 7 PSI kit would calculate as follows:

A.) 7 PSI divided by 5 bands equals 1.4 PSI per band.

B.) 1.4 PSI multiplied by 4 bands equals 5.6 PSI.

C.) The 5th band should then activate at 5.6 PSI for an 7 PSI kit.



The scalar adjustment can be made with a reliable, regulated pressure source (CO2 bottle with low pressure regulator works well). The procedure is to apply the calculated pressure from above to the boost reference port. Then, adjust the scalar pot (silver, arrow shaped pot in the lower left corner of the DFMU) so that the light over band 5 just turns on at that pressure. This is the process used by ATI Pro-Charger when the boxes are pre-calibrated to a safe tune at the factory. Note: the scale engraved on the face of the DFMU, around the scalar pot, is not calibrated directly to boost, it is just graduated for a reference. The pots themselves are set on the board beneath in the same fashion for each unit. However, particular or exact alignment from board to the next, in order to ensure that the arrow would point to the exact same scale line, at the exact same pressure on every unit built, is not an assembly criteria. Do not expect that, from one unit to the next, there will be an exact correlation between the position of the arrow and the actual calibration of the scale to a certain PSI of boost.

______________________________________________

I sure hope you can get things figured out.

-D'oh!

 

Thanks D'oh, i appreciate the help.......the last slider is functioning properly, but mine is set up differently from the example that you gave

You see, for each slider, there is a range of boost that it covers......so this means that there are a variety of increasing levels of boost that are fueled by the same FMU setting.......like to use your example, the first band would be providing the same amount of fuel at 0.2 PSI, as it would at 1.3 PSI......so you can see how for each slider, the AF ratio goes from rich to lean......rich at 0.2 PSI, and leaner at 1.3 PSI, since we have more air, but the same amount of fuel.

Keeping this in mind, my FMU was set up so that the last slider comes on for the highest portion of boost......my last slider comes on at 6-7 PSI, so that i get the richest setting that i could possibly get when i'm at the highest boost values that my engine will see.

Take a look at This Thread , it will explain everything that is going on with the Prochargers in relation to the stock ECM.......i've spoken to a few people that attended SEMA.....and it appears there are more fried Procharger motors out there than this forum knows about