Reignman

Hello,

I was wondering how daily driveability is with the MAP sensor over the MAF sensor. Do you really have to fine tune your A/F ratios to get the car to run smooth with the MAP? I had a turbo S2000 before the Evo (S2k has a MAP sensor) and it was the worst thing to tune. I couldnt get the A/F ratio to stay where I wanted it and it drove like crap. I know the Evo it differant but how does weather and season change effect the tune? I drive around 100 miles a day so I want to keep the car driving smoothly without having to retune often.

Also I was trying to decide between the UTEC and the AEM EMS. Have any of you used both units? I was looking at the UTEC because it is less expensive and I dont think I need all the extra features the AEM EMS has. Any opinions on which would be better for a daily driver with around 350-400hp?

Thanks

MalibuJack

iTrader: (5)

I don't know of anyone who is using a MAP sensor IN PLACE of the maf sensor.. In fact I don't know that its possible, its not documented well in the UTEC docs so I did not attempt it.. But just so you know, just using the MAP sensor is not the same as "Speed density.."

And unless you plan on making 500+ whp an EMS is just overkill and it needs quite a bit of effort put into it to tune and get to be drivable, especially for a daily driver.. Don't get me wrong, It CAN be done with the EMS, but you can't beat the stock ECU for drivability.

the stock MAF sensor (disregarding the quirks) can handle enough airflow for 400whp

A UTEC alone is almost 1/2 the price of the EMS (though the Tuner/Utec combo comes close in price, so weigh what your ultimate intent is)

I do have experience with standalones, and learned very early on that it takes alot of work to get to the same point that I am with my UTEC and stock ECU.. the UTEC does have some features that the AEM EMS just doesn't have, and the EMS has lots of features that the UTEC just cannot do currently.

I wish someone who has tried removing the MAF in place of the MAP sensor would chime in, but from what I know and what is documented, it doesnt entirely replace the MAF but provides a load reference for the Fuel table that can be used instead of MAF frequency, but I think removing the MAF would result in a Check Engine Light since this information is passed through to the stock ECU..

There is talk speed density will be possible in the future, but if they did offer it, it might require an Intake Air Temp (IAT) sensor added to the harness somehow in order for a true speed density system to work.. the UTEC's hardware is capable of doing this, but AFAIK It has not been attempted or coded in the firmware.

Reignman

Maybe I havent read up enough on the UTEC but I thought it was a standalone setup. I really would rather stay with the MAF but I hear that it really is a restriction and removing it can gain up to 20+ hp. I was considering the UR blow through MAF but it is rather expensive.

I really want a good fuel management solution. It doesnt have to be a standalone but I want to be able to adjust timing and have logging capabilities. I was looking at the Emanage at first but it seems like people are having problems with it frying coil packs.

BTW. Does the UTEC tuner have to be purchased to tune the UTEC or can it be done through a laptop or palm?

bbbwrx

iTrader: (10)

You do not tune the Utec through the tuner. The tuner is a system that gives you the tools to tune your utec. Like a head phone jack to listen to knock, wide band etc... Check HERE for more info.

Ben

Reignman

Thanks. I need to read up more on the UTEC's capabilities. I already have a wideband but the knock detection sounds interesting. Is there a way to connect a palm to tune the UTEC without using this seperate unit?

MalibuJack

iTrader: (5)

Yes, though using a Palm screen means that its difficult to work with.. The UTEC is formatted for a typical "Terminal program" which is 80 chars wide by 24 lines.. I use a HP Jornada Handheld PC (Windows CE based) but it has a more conventional display. But you can use ANY device capable of reading a serial terminal device (VT100).

Well.. with knock detection on the tuner, it is something you can use, but the UTEC does "see" the stock knock sensor, and you can use that for tuning (though you can't "listen" to it like most human tuners might) I have my threshold set pretty low on the knock detection on the UTEC simply because my car seems to be a bit less knock prone so I chose to be more cautious..

The only REALLY COOL advantage of using the UTEC and Tuner is the integration of the two.. the wideband data is shown with the UTEC data which allows you to gather data and log it.. which means you can do pulls, and examine them later... You still need to hook up a PC or PDA to gather that data...

MalibuJack

iTrader: (5)

I chose to go with a blowthrough setup over speed density conversion.. A true speed density setup is something the standalones (AEM EMS, and APEXI D-JETRO I think) can do easier than a piggyback since in addition to using speed density, a piggyback/passthrough system would have to "Reproduce" the output to make the factory ECU happy.. This WILL eventually be something that you will see on the UTEC, but it does take more than just using a MAP sensor..

Having enough experience with speed density, I associate it with a throttle-body type injection system compared to a port fuel injection system.. In other words, it does the job, but its one step up from a carburetor, Obviously thats only my personal opinion and many will argue that speed density IS the way to go. But MAS systems determine the actual mass of the air, where a speed density system calculate its air mass based on manifold pressure, throttle position and intake temp, it cannot calculate for other anomolous scenarious such as high humidity or sudden changes in air density (not that it actually happens very often). It also is more difficult to make drivable since it doesnt really know HOW MUCH actual air is passing through it, just how much pressure/vacuum is in the system. A MAS system always knows how much air is passing through it.

erioshi

Kind of an OT question, but have you done much with closed loop tuning yet, JacK?

MalibuJack

iTrader: (5)

There's not alot to closed loop tuning, there are 4 closed loop parameters in the factory ECU that can be adjusted, and those are "baseline values" or defaults that are flashed into the ECU Those are the long term and short term base fuel trims.. The ECU always tries to maintain 14.7:1 AFR's in closed loop, so the fuel trims will eventually adjust and do the job.. (thats why when you look at fuel trims in an OBD-II diagnostic tool, you will see long term and short term values their at 0% when you reset the ECU, but depending on your mods, they may be +/- 5% or greater after a few runs)

you CAN however help your ECU relearn faster by tuning the regions you would typically see closed loop operation to help your idle when the car runs open loop, or so the base tuning is "Closer" to what the ECU expects to see (Tuning for Poor idle mixture, or other modifications so the ECU doesn't have to hunt for trims as hard) if the ECU is reset and has to relearn from its base. This I have done, I've added +3 or so fuel in the 0 and 10 columns from 0-3000rpm which typically fall into low load, part throttle closed loop operation. This helped the car run better when the ECU is trying to relearn after being reset (I know I repeated myself)

There is one thing I'd like to see added to the UTEC, and that is control over the Idle Air compensation motor (idle speed) so that I can bump idle up or down a few % without making external adjustments.

2k4EvoVIII

iTrader: (15)

I decided to go with the AEM and i got the MAP conversion which will be getting installed this weekened. Im not gonna be able to run the car hard until i can get it on the dyno and get a real tune going but like someone said earlier you are supposed to gain 20+hp out of the conversion. I will keep you guys posted on how things work out.

MalibuJack

iTrader: (5)

Just verify that your state's inspection doesn't and will not require OBD-II in order to pass inspection... You don't want to get a surprise in the future.. Good luck..

2k4EvoVIII

iTrader: (15)

I live in the backwards state of Washington. And there are no emission laws that we have to pass like CA does. By that i mean that you dont have to bring your car to get inspectd ever after you have bought it! Gotta love it!

MalibuJack

iTrader: (5)

Even better.. then hook that baby up.. I did hear that there was to be some federal regulations at some point, but enjoy dude.. your one of the few who can pull it off!

2k4EvoVIII

iTrader: (15)

Ya i heard the same thing for like the last 5 years but nothing yet. Well i guess we will see how things turn out. I will let you know how it goes with the MAP conversion.

Reignman

Well after reading up more on the UTEC Im am interested. It is pricey for a piggyback but it does have many of the features of a standalone while still maintaining the stock ECU.

Jack. Do you have the UR blow through MAF installed? How is the system working for you? Im actually surprised that the stock MAF isnt setup like UR where it is closer to the throttle body. I would think it would have more accurate readings just before it enters the engine.