3G or EVO MAS wiring

Pin 1 = +5 volts
Pin 2 = Barometer
Pin 3 = Airflow Hz
Pin 4 = +12 Volts from MPI
Pin 5 = Ground
Pin 6 = Intake Air Temp
Pin 7 = Reset

So, the correct crossover wiring to our MAS plug is:
3G/EVO Pin 1 to 1G MAS Pin 4
3G/EVO Pin 2 to 1G MAS Pin 7
3G/EVO Pin 3 to 1G MAS Pin 2
3G/EVO Pin 4 to 1G MAS Pin 3
3G/EVO Pin 5 to 1G MAS Pin 6
3G/EVO Pin 6 to 1G MAS Pin 8
3G/EVO Pin 7 to 1G MAS Pin 1

The GOOD 3G MAS to find is the #482, from the Variable-Induction V-6. It flows about 99% of what an EVO MAS does. /ubbthreads/images/graemlins/cool.gif
I cut up the base to our stock aircan, and mounted the 3G MAS inside, so it looks like stock! Pictures to follow.

 

I think this may have been discussed before, but what is required to compensate for the 3G MAS? Do you need a chip, or is it basically the same output as a 2G MAS?

 

I cut the front mounting ring off my old GVR-4 MAS, and JBWelded it to the 3G MAS:

I had to move the connector cutout about 1/4", due to interference with the 3G MAS. I JBWelded a piece of sheetmetal underneath the aircan, and another piece fitted to the hole, to bring it up flush. I also had to then drill new holes, and tap them:

I also had to JBWeld the connector gasket unto the connector, as there was no longer any way to attach it inside the aircan:

Here's the finished MAS, almost ready to put on the car:

I had hoped that this EVO K&N setup would all fit inside the aircan, but it was 1/8" -1/4" too long. With some work, or a slightly different filter assembly, I think it would fit. However, since my REAL intention was to use the 1G K&N I already had, I didn't try to make it fit:

To use the 1G K&N, I ended having to hack all 4 mounting corners off the 3G MAS, and also remove the plastic shroud that surrounds the 7-pin connector, to allow the filter to slide on easily. The only 2 bad things I ran into:
1) there isn't any place for my BCS return vacuum line, so I have a small vacuum leak at the moment
2) the step inside the aircan doesn't allow you to use a 3G connector, so I just soldered all 7 wires directly unto the pins, and shrinkwrapped them. I'll try to put a couple more pictures up (tomorrow when the rain stops)of the finished installation. It looks TOTALLY stock! /ubbthreads/images/graemlins/cool.gif
With my new 3G MAS correction code, #880 started right up, idled perfect, and runs wonderfully. I can actually feel the difference in power, just from removing the restriction the stock MAS causes. /ubbthreads/images/graemlins/grin.gif
I know other guys have used 3G MAS's, and have some issues, but I think most of the problems stem from the fact that this MAS flows 25% more air for the same Karman Hz as a 2G, and 67% more than a 1G, so you have to add a LOT of air on an AFC.

 

[a_santos]

So Jeff, what you are saying is the the best Mitsu MAF if the 3g or EVO mas? That is good news since they can be had for cheap.

I better start looking for one of those. /ubbthreads/images/graemlins/smile.gif

 

The #482 V-6 MAS flows so close to an EVO MAS that the 2 could be interchanged, and no one would probably notice. The graphs I've drawn show them less than 1% different, as far as Hz per liter of air intake, airflow capacity, and air pressure drop.
I'm trying to get ahold of an EVO MAS, so that I can test it 100%. But, if you look at the #482 MAS, you will see that the entire 3" inlet is unobstructed, unlike the more common #501 MAS and others that have the airhorn covering part of the inlet.

 

[atc250r]

Jeff,

Is the #482 the one I sent down to you?

John

 

Wow, great work. How does this compare to the GM maf?

 

[steve]

And how does this compare to the 2g MAS?

 

Quote:
Wow, great work. How does this compare to the GM maf?


I can't say, as I don't know all the specs on a GM 3" MAF, but I doubt it is quite as good. I'd say this MAS has got to be good to at least 400HP, like the 2G, but the GM MAF is made for MUCH higher HP applications. But, its not nearly plug-and-play, and then you have all the tuning hassles. I'd say that if your HP goals are 400HP or less, this MAS would be a better choice.

Quote:
And how does this compare to the 2g MAS?


Its gotta be better! /ubbthreads/images/graemlins/wink.gif According to the spec sheets, the #482 MAS and EVO MAS have

 

[atc250r]

It was the least I could do for you after all the help you've given me.

John

 

" this MAS flows 25% more air for the same Karman Hz as a 2G, and 67% more than a 1G, so you have to add a LOT of air on an AFC. "

Jeff base on you info 2G MAS flow 29% more than stock 1G...so 67%(1g) - 25%(2g) = 42% different...but why 1G to 2G only 29%...is there a way to calculate this...

1. 1G to 2G = 29% ,so if I change the to 2G MAS, can I just add 29% on the safc for all RPM point from stock setting? (MY ECU are JDM dual board so can't logging..need to go wideband dyno for actual setting confirmation, so i need the base setting first before going for dyno..so far changing from 1G MAS to 2G MAS i can feel it pull a bit harder than before)

2. some of 2G come from stock with screw flush out and some are in..like mine i got stock evo3 (2G mas) with screw flush out...it's it still 29% different

3. 3G MAS / Evo MAS flow that you are calculate base on screw in or out?

 

[Yiuwa]

I also have another question - since this MAS has round exit could it be installed right before throttle body elbow (i.e. after turbo) like the others do in GMAF setup? If that's feasible then my vent-to-atmosphere BOV won't give me wrong airflow figure after letting go some calculated air (don't blame my setup, I know I shouldn't be doing this

/ubbthreads/images/graemlins/tongue.gif

 

I don't think so. The MAS wasn't intended for the heated air post-turbo. I can't tell you what would happen.

 

Quote:
1. 1G to 2G = 29% ,so if I change the to 2G MAS, can I just add 29% on the safc for all RPM point from stock setting?


Yes, thats a good place to start, except at idle/low airflow. This should help:
http://www.dsmchips.com/~keydiver/MAS_CORRECTION_1G_2G_3G.xls
It shows the correction that is in the ECU for the different MAS's, compared to each other.

Quote:
2. some of 2G come from stock with screw flush out and some are in..like mine i got stock evo3 (2G mas) with screw flush out...it's it still 29% different


I wouldn't touch the screw. That is a factory calibration, to make the MAS flow to match the curves in the ECU. If you turn the screw out further, you will have to add more airflow on the AFC.

Quote:
3. 3G MAS / Evo MAS flow that you are calculate base on screw in or out?


The charts are all with the screw as set by Mitsubishi.

 

[steve]

Quote:
The MAS wasn't intended for the heated air post-turbo.



Neither was the GM-MAF, right?

 

Quote:
Quote:
The MAS wasn't intended for the heated air post-turbo.



Neither was the GM-MAF, right?



Well, no, but it's also based on a different measurement principle, "hot-wire", which lends itself better to blow-through applications. Not to mention the GM MAF's are shaped/sized in a way that works easily (round, adapts to IC pipes easily).

 

[Bimmubishi]

Any comments on the MAF's internal tables and airflow count capabilities? Not just the physical airflow properties.

The 2G looks to be bigger than the EVO at a glance this is why I ask. I assume that the EVO is a more developed unit.

 

Quote:
Any comments on the MAF's internal tables and airflow count capabilities? Not just the physical airflow properties.



One spec I CAN compare from the data I have is the pressure drop:
about .5 psi MAX for the 3G
almost 1 psi for the 2G. But, this is the MAXIMUM manufacturing spec, so there is nothing saying they all lose that much.
Another spec to compare is the maximum airflow they are made to count:
2G = 2700 Hz MAX at .1153 Hz per liter = 311 liters per second
3G = 2200 Hz MAX at .1478 Hz per liter = 325 liters per second
When you compare this to the anemic 1G MAS with .090 liter per Hz and a 2000 Hz safe cap, thats only 180 lps! /ubbthreads/images/graemlins/shocked.gif
As you said, I think looks must be deceiving, because the 2G MAS appears larger in cross-sectional flow.
Also, if you look at the graph I posted, the 3G is much more linear at the lower airflows, again indicating that it is a more refined MAS perhaps.
This MAS was designed to be used on some big V-6's, like the 3.5l Montero Sport, or the Eclipse GTS model I believe.

 

[G]

WHAT do you think an evo 8 mas is worth ? street price.

 

Quote:
WHAT do you think an evo 8 mas is worth ? street price.



Is there anything that you won't sell?