umiami80

iTrader: (1)

I was speaking to a well known and trusted tuner today about Stand Alones and the AEM EMS in particular. He had told me that converting to a map sensor is not really needed on an Evo and is actually NOT as accurate. The MAIN benefit is that it is FAR easier to tune for as you are only tuning for 1 element. The final tidbit of info that flashing is harder YET retaining the MAF will allow for better throttle response and better power if the tuner actually spends the time to tune. He also said the Map system is older and not as accurate.

Is this True?

David Buschur

iTrader: (53)

It has to be true, it was a well known and trusted tuner, wasn't it?

David Buschur
www.buschurracing.com

VTECH8TR

iTrader: (70)

hahahaha......

P.S. Speed Density rules .

umiami80

iTrader: (1)

I also see that people are making the same amount of WHP on flashes and EMS tunes. I myself am in the upper tiers and make more WHP then many EMS gusy with same mods. IDK, how about some insite about MAF Vs. Speed Density?

Throttle Response?
Accuracy?
Miscounts?
Peak power?

GTVEVO

iTrader: (22)

I tuned my car fully with and without the MAF and the experience I had was that when using the MAF drivability is easier to tune because you are actually measuring the air and you are doing this before it goes into the intake manifold so the reaction is further ahead and more accurate but then I felt the AIT was hard to rely on due to it being further out and not close enough to the throttle body to read the actual temp of the air the engine was getting. Your tuner is correct on the exact measurement of air.

When I tuned with the MAP in the car my results were more power on the top end. How much more power, I can't honestly say but it did seem that the stock turbo didn't have to work as hard and I could hold more boost consistently. I think this is one of the biggest reasons most people convert to speed density, to get rid of any restriction regardless of how big or little. Another good thing about map is that the AIT sensor is right before the throttle body so you can tune things out better and not have to worry about heat soak and a fast transition of intake temps on either hot or cold days to help performance and reliability. Next you can tune to be sure you are getting the most power and or safety with your setup on any type of fuel. The AIT problem could probably be fixed while still running a MAF so keep that in mind also. But on the bad side daily drivability (normal driving) takes some serious time to get things just right so you feel like you have a daily driver you can depend on while getting the highest amount of power while still getting good gas mileage. Please be aware I don't recommend a standalone to anyone unless they are willing to learn it themselves. I am not a believer in taking it to someone else to get tuned because things will need to be changed at one time or another to get the best possible tune for daily drivability and power.

The AEM has so many features for the price I feel that it is truly the best and so do about 90% of the vendors if you are to choose a standalone. Allot of people do get the wrong picture with standalones though thinking that they can simply plug them in and get an extra 50 hp when going from other upgrades such as a flashed ECU, Xede, SAFC, UTEC it won't happen on that large of scale if any at all depending on the mods you have. Please remember this is just my experience and I run the AEM.

AEM > Peak Power
Responce = if tuned perfectly
AEM > Accuracy High air level / AEM < Accuracy at low level (you give on for the other)

umiami80

iTrader: (1)

Great response.

propellerhead

iTrader: (3)

Get the best of both worlds: convert to a large bore GM-style MAF and use it as an input into the EMS.

Z1 Performance

iTrader: (185)

a properly tuned MAP based system has nothing but benefits vs the MAF on a forced induction car

Tuning wise, yes it's more time consuming setting a car up MAP based, but it is so worth it in terms of boost response, and fuel control, and overall power

bluevo

Amen, that's why I leave the tuning and maintenance of my AEM ems and map to the experts....TurboTrix that is......thanks to you guys, especially to Mark whose patience and complete know how of this system helped me out one cold morning (via phone) to remap my system to cold weather settings and without any problems my car went through the winter driven everyday.

feldguy

iTrader: (4)

I plan on giving it a go myself, after reading and taking notes through the entire manual. I've got my laptop ready to and want to run the two channel UEGO and see how close the autotune can really get. I just wonder, is .1 AFR point accurate enough? I mean, it could be +/-, so if you target 11.7-1, it could be 11.9-1 or 11.8-1, correct? What makes a shop so much better, more accurate o2 sensors? Will the two channel UEGO be more accurate, as it can interpolate the differences between the two sensors?

Oh yeah, MAP all the way!

MalibuJack

iTrader: (5)

Well, the MAF has its issues, but I use a blowthrough setup that eliminates two of the complaints most people have about the maf, which is low airflow issues (idle problems) and misreads/disruption of airflow or blowoff valves/whatnot.

A properly tuned speed density system runs great, but the difference is a speed density system is a calculation, a MAF system is an accurate measurement (within reason)

I have been running a blowthrough FORD based MAF for over a year now, good drivability and no major idle issues that can't be resolved with some simple adjustments.

There is only one real downside to using an aftermarket MAF (besides a 90% ignorance of its existance) and that is on some types of hot-wire maf sensors, you can get some condensation on it when its cold, so it takes a bit longer for the wire to warm up and read correctly... THis seems more common on the GM sensor from the complaints I've heard.

I realize the question is of a stock maf verse speed density.. I still think a properly tuned car running MAF will be more drivable, and be more accurate to engine demands.

There's benefits to either setup.. If your already running a standalone, you might have to seriously weigh your options (The first major advantage is you can swap a stock ECU back to a MAF equipped car without any other changes to revert it, assuming your other mods don't get the ECU cranky)

But if your debating AEM vs Stock ECU, well I have a slightly biased opinion so its unfair for me to comment on..

1) Legality (OBD-II)
2) Adjustability and expertise
3) Data logging ability
4) Drivability

You have to rate each of these things and see which is a higher priority to you, Since several products can fit the bill..

I personally don't think a standalone is a great idea for a daily driver, but there's many guys who are running them and driving their cars daily. Also you have to look at your local inspection stations requirements for OBD-II check and whatnot to pass..