Why wouldnt you want to tune FI with a maf sensor? Its not like its bad or harmfull, and the car would run like stock under boost.

Booger yes it will be able to tune FI vehicles.

As as the fuel control I thought that in a returnless system, like the one on the Z the ecu controls the relay to turn the pump on and off, and it controls fuel pressure that way.

The programs I have are still beta, but are looking very promising. I will tell you that there is an option in one part of it to change the MAF scale and injector scaling.
It will work fine with FI.

 

Im running a SC {Custom Vortech} around 20 psi at redline . If this Osiris will tune and keep every thing safe , be able to switch maps . Wow..that would put a damper on all the aftermarket EMS sellers .

Will be looking for a F/I car to tune with this....who is going to do it first ????

 

You can't tune off of the stock MAF because the voltage will be maxed out after about 6 psi (according to the UTEC manual).

Dovla > I was wrong about the MAF cost, I see you can get a Ford Lightning MAF for $100 (is this really true?). I look forward to seeing the end user version that can be calibrated to an aftermarket MAF so we don't have to worry so much about temperature corrections for MAP.

UTEC is controlling boost for me as well and there was a hope (perhaps still is) for a software update to ease tuning and increase functionality - so I'll stick with it a while longer... but always looking for a better mousetrap

 

The stock fuel system uses a mechanical fuel pressure regulator to (try to)maintain a static pressure. Once the fuel pump is on it stays on constantly with no modulation or change in voltage.

I don't know the exact differences between MAF tuning and MAP tuning, but from what I've picked up the MAP sensor will give you better boost response, better fuel control, and more overall power with the major drawback that it will be harder to tune at idle. I could be completely wrong on this, but that is my understanding.

 

That may be true but if this software is like the Cobb is supposed to be they might be able to redefine the range of the MAF signal so it doesn't max out.

 

Westpak, well that would be very nice indeed. Rocks can you confirm that this is possible and what would be the limit of the stock MAF in this scenario?

 

If you can scale injectors, I don't see why you wouldn't just run a return fuel system. Why mess with returnless (like in the JWT kit) using a rising rate regulator?

 

The stock MAF is at its limits at around 8-9 psi proven with the turbonetics kit. A 3.5" MAF sensor that will meter way over 20psi will cost probably 150$.

 

I always wondered why AEM never release their EMS standalone for VQ engines.

I bet they've looked at Nissan's ECU, saw that it was easily programmable and said, heck this thing can do 80% of what ours does, why bother.

Art

 

ART - I think it's because of the drive by wire... no aftermarket company wants to mess with it, because if you manipulate the DBW signal and it fails, and the throttle sticks open, then that company could be liable for any damages or deaths that occur

Most of the "standalones" (IIRC) let the factory ECU control the DBW because then the burden is on Nissan to have a fail-safe mechanism to keep the throttle from sticking open .

 

You're probably right. In any regards fact is OEM ECU could be easily programmed, I am sure soon someone will make a generic ROM loader and you would be able to upload and modify your maps with a $10 Ebay cable and TunerPro.

Art

 

Interesting. Thanks for the review.

So, UpRev can tune in-house at their Austin shop, or simply re-flash based on their database of tunes done on cars running a similar set-up to your own? And now you can self-tune by giving it a specified A/F ratio and letting it work from there? Does this about sum it up?

Will

 

All but the self-tune part.

That isn't out yet.

 

Interesting info. I've tuned based on MAF before and it's actually pretty easy. If you can stay within the MAF sensor's range, you're good to go. The nice thing about MAFs is that they're accurate and are very responsive to changes. As long as you get good, laminar flow around it, you will get good readings and the nice thing is that pressure and IATs take care of themselves as far as flow readings. It tells you what you're getting and that's it.

MAP tuning is a bit different. The big thing with speed density is that you need an accurate VE map that matches your engine exactly to be successful. That map is developed by whoever makes the engine by testing it's breathing ability based on RPM and throttle modulation. So, technically, you're running off a predefined set of values, throw some MAP sensor readings into the formula, add IATs and you got your flow. But, it's not a true real time system, more like a open loop mode, in a way. Many guys swear it's better but I would not give up on MAFs just yet.

Generally, OEM ECU has a 2D map that defines its voltage scaling for the MAF sensor. If you are going to run with a big MAF setup, just rescale the map to match what you have and you're done.

I am not surprised you had idle issues with UTEC. Seems like a common issue especially if you were using the MAP sensor. Also, you had cams which alters your VE properties so that UTEC Z calibration was off now. Cams were probably contributing to your issues. This is where speed density falls short.

 

Do you know what flow that translates to? What is that kit rated at? A bigger snail with less pressure will produce more flow than a small one with higher pressure. Is the stock sensor maxing out around 4.5V?

 

I never had idle issues with my UTEC, I was speaking generally.

The UTEC doesn't control idle in speed density mode, it uses the OEM ECU which is still MAF based for idle control.

 

I do not know what the flow translates too. I have not dug that far into it. I suspect eventually uprev will have that info and you will be able to buy a maf from them and just put the settings in. They can scale injectors and MAF at thier shop. My stock maf gets up around 4.3v on a NA engine.

 

Sounds good. Your idle issues were related to something else than. The most common issue is the way the injectors are tuned. I can only guess at this point. I was directing my comments to the OP but I didn't really say that so I can see how that was unclear