MardiGrasMax

iTrader: (14)

So what is the difference between MAF and MAP tuning?
I am at the limit of the Z32 MAF and am planing on using my e-manage to add injector duty cycle using the MAP. I have been data logging to help me create the settings for the e-manage "Additional Injection Map". This is based on MAP in KPA. I have noticed that atmospheric air temp can make a difference in the corolation between MAF voltage and MAP KPA. When its ~70f It takes MAP 140kpa for the MAF to show 4.9v. When its ~30f I only took MAP 100kpa to produce MAF 4.9v. What this shows is that using MAP with out IAT is dangerous at high boost levels and you need to monitor this. Basically the MAP sensor does not take into account increased air density when its cold, where as a MAF does this. In my case I am trying to find the spot where the MAF max's out and the e-manage "Additional Injection MAP should start adding additional injector duty cycle. Based on what I am finding this could be anywhere from 100-140kpa dependent on air temperature. Realistically I doubt I will ever run 25psi of boost when it is 30f outside, but even 50f is realistic. I need to datalog at 50f But I guess it would be safe to assume the at 50f it would take MAP 120kpa to get MAF 4.9v. So their could be a 20kpa (~1.5psi) swing in when the MAF max's out and the e-manage would need to add injetor duty cycle. If it gets to be 90f outside it will take even more KPA to max out the MAF sensor. For you guys using stock a stock MAF and using the e-manage be carefull!

So what to do about this. If tuning with a MAP sensor only tune in the winter spring or fall not in the summer heat! If you tune in the summer you could end up being very lean and blow your motor. Tuning in the winter will cause you to be rich in the summer, which is a good thing for those with out wideband O2 sensors. For a 7psi car this might not be a big deal but on a 14psi car it could be.

I also spent a little time talking to John at J&S and he has developed a new interface to make the J&S able to work with the e-manage! I should have one shortly!

Y2KevSE

iTrader: (13)

You will also get different readings in different altitudes (i.e. tune at sea level then boost at 3000 miles above sea level).

Here's an interesting discussion that the EvoM guys are currently having between MAF and MAP setups.

http://forums.evolutionm.net/showthread.php?t=173893

Good luck!

turbo97SE

iTrader: (3)

Matt you are correct! For a given altitude, you can get up to 10% variation in density in air from 30F to 100F. This is why many MAP based emses have compensation tables for Air intake temps. Good ones also have compensation for timing advance too since spark propagation speed is also dependent on a/f mixture temperature (but that is more of a second or 3rd order effect in terms of extracting most tq/hp). There are other variables in your system that adds to equation. In reality, you probably want to tune on the richer side of things anyway, but yes others should heed the warning you have given. Tuning in colder weather (or moderate weather) with a 5% to 10% margin of error is indeed a good thing but matters more for higher HP motors like yours. On my setup, I have indeed run into issues like this with some misfiring in colder weather under partial throttle not full throttle issues, these require a little tuning but not much.

Bernardd

I did the following based on your info: 4.9vdc / .08vdc per vq cell = 61.25. For safety's sake let use the result as an indicator that your ecu is using vq cell 62. The percentage of max flow at that cell is 59091/65535 * 100 = 90. You do not need to worry about the map sensor until you increase your airflow by more than 10%. At this point I would scale the entire maf voltage down to make sure you're not hitting the 5.12vdc max and retune. There is most likely a voltage that will cause the car to go into limp mode. Keep your idle voltage above this point. If you still max out the maf , and I hope to see you do that, there are other methods of extending the maf flow capabilities.
I would have more concern that jwt didn't map the tables to use the entire maf range, but as long as you can keep the maf voltage below 5.12, all should be good. (I saw your quest for ecu info on another forum)

Kevlo911

iTrader: (36)

SMT7(and I think the EU) can convert cars that have MAF based systems to MAP.

DA-MAX

iTrader: (10)

and from what I've read you basically have to do the same almost as Matt was decribing. for EU, drive the car as normal with the MAF, than go back through your datalogs and make a basemap in the Additional Inj map based on the voltages that were logged. but you also have to make a supplemental map for the coolant temp table and a few other tables I think. it seems pretty simple since one you enter a few values you can just interpolate the rest of the table and viola. there is a really good post about it in the Miata forums outlining it.

Larrio

iTrader: (10)

Could you try using a larger MAF (Q45 maf possibly) to simplify the process?

MardiGrasMax

iTrader: (14)

I could go with a Ford Lightning MAF, but I am too cheep. I am going to use the MAP feature on the e-manage, but be very carefull on the tuning.

maxmaxima91

The Q45 maf is physically larger than the Z32 maf but it cannot read to as high of an air flow.. Basically its bigger but much more sensitive. What i would recomend is either a lightning maf or a Dual maf setup.

jeremy

slimer

iTrader: (13)

I hear that the Mazda guys are having more ecu resistance with the EMU, so if they can convert from a hotwire to a MAP, then it should be fairly easy to do it with our ECU. Is the interface on the EMU that hard to work with.

Redmax

iTrader: (20)

The Emanage interface is pretty simple however the additional tuning map is not self explanatory in anyway. Also the only instructions on using it are pretty cryptic so, you basically have to wing it

subs1000w

couldnt you add an IAT sensor to the EU to automaticly take care of this it would aslo be good to log this anyway

DA-MAX

iTrader: (10)

according to this, yes--->

http://mohdparts.com/emanage/ultimat..._manual/20.jpg

and logging IAT valtage would be very helpful in making the supplemental add inj map.

IceY2K1

iTrader: (3)

The EU already taps your IAT, so nothing to add.

I'm just trying to figure out how to have two, ie add another, so I can log inlet air temp and air temp before the TB.

subs1000w

then why cant it compensate for temp fluctuation when overriding the maf since thats how speed density works

turbo97SE

iTrader: (3)

You're probably more interested in temp just before throttle body. you could just add a GM IAT sensor to your TB pipe and call it good. By the way, is what you get in degrees F (or C) or just a voltage? I haven't played with the emanage stuff at all.

IceY2K1

iTrader: (3)

The EU can, Mardi has the BLUE.

IceY2K1

iTrader: (3)

I agree, however I'd like both for the delta.

It can output both F or C IIRC...not really sure though.

MardiGrasMax

iTrader: (14)

More importantly, IAT and timing.

IceY2K1

iTrader: (3)

Say again Mardi?

MardiGrasMax

iTrader: (14)

IAT and how it relates to timing. EU only does IAT and fuel I think.

Bernardd

Quick check on ebay shows z32 mafs going for around 130ish and Lightning mafs for around 80.00. Even cheaper is popping the sensor out of the housing and placing it into a bigger pipe.

IceY2K1

iTrader: (3)

So, you want to pull/add timing based on IAT?

For the EU, I would think that pulling/adding timing via the pressure sensor alone would compensate for more/less dense air. There is an "Option" port that can be configured for the Greddy IAT, however when I choose it, it doesn't change the load axis for the Timing Adjustment map. It will probably be available in a future firmware release.

DandyMax

iTrader: (7)

Yeah unfortunately Mardi at this point it seems the only timing adjustment is via a load axis referencing pressure, airflow, or TPS. There are air and coolant based adjustment maps but those only modify fuel.

This would be something to put on the wish list for Greddy. Some more timing adjustment based on air and coolant temps would be useful. I'll mention it to Kenji next time I talk to him and see what he says.

IceY2K1

iTrader: (3)

While you're at it...ask for a "Virtual Gauges" screen like the OBD guys have.

DandyMax

iTrader: (7)

Whaddya mean? I can use my Consult clone software for that...

But ya, you're right that could be useful too...

IceY2K1

iTrader: (3)

It should be a piece of cake, since they already output all the data in the logging window. It would just be nice to have a virtual gauge gui when driving with the laptop on.

DA-MAX

iTrader: (10)

VERY interesting...I wonder why? limitations to the software?

DandyMax

iTrader: (7)

Who knows. It wouldn't have been hard to program I think. For whatever reason they didn't include it so far...

IceY2K1

iTrader: (3)

Because it's not necessary for most of those who'd use a piggyback and not a standalone would be my guess. The nice thing about the EU is that it is SIMPLE and easy to setup/use for the beginner to the advanced user. As good as the newer standalones are getting with the numerous abilities, they still do one thing, ie make things more complex then many users need/want.

350Z guys are running 600+whp with the BLUE emanage and the Ultimate can go even further. Once you reach that kind of level, you'll probably choose a standalone for ultra control.

DandyMax

iTrader: (7)

You make a good point, but I must say that was one of the things I did notice when I first got the EU. Looking through all the options, maps etc I remember thinking to myself, "hmm... there's fuel adjustments for air and coolant temps but not timing?" It just seemed like a logical extension to me. Maybe that's just the way my brain works, but complexity doesn't bother me, I actually prefer the advanced degree of control even if the complexity is greater. And I'd also been doing a lot of reading up on the capabilities of various standalones, even the better ones such as Motec etc so everything was fresh in my mind.