bahamut

All 4g9x uses the same block, not necessary the same MAF. The MIVEC 1.6L uses MAP (a cyborg owner in Jamacia corrected me after I though he was missing an MAF from a pic of his engine bay). I'm unsure on the 4g93T in the 4g and 5g Lancer (pacific rim cars) . . .

The US spec mirage 1.8L and the lancer shares the same MAF, except for the 97 US spec mirage (I'll find the link somewhere). Mitsu shared the MAF as a cost-saving measure to save on parts.

The 3g eclipse in both flavor of the 4g64 and the 6g72 share the same MAF as the 3000SL and NA 3000GT's 6g72 . . . not sure on the VR4, never seen its engine in person.

bahamut

Well, you have to say which gen 1.8L . . . the 4g is flipped opposite to the 5g mirage. The 5g mirage's 1.8L is just a baby motor to the 4g94, which has upgraded intake manifold (not log style like the mirage), .5 mm smaller bore w/ way shorter stroke, and possibly a slightly different cyl head design . . . no one has cracked open the 4g94.

bahamut

http://www.boostaholic.net/phpBB2/viewtopic.php?t=599

here's link on our board on the model # between mitsu.

http://www.boostaholic.net/phpBB2/vi...&highlight=maf

MAF mods - only 3 people have done it . . . a guy in AZ, DIM, and me. All of us have gone different route, and performance may vary drastically. Basically, DIM has the most internal and external motor mods (still using factory exhaust manifold) . . . the guy in AZ is tuning his w/o an AFC via by the seat of his pants . . . me, the least amount of mods compare to the other two.

I cannot stress to do this correctly. You must need more mods to justify getting an AFC . . . just having an intake and exhaust are just not money wise spending on an AFC.

Afterwards, attempt the MAF off the 6g72 or 4g64 - Mistu's bigger displacement NA engines. Both are the same.

As for performance, I cannot speak for the other 2 two. IMO, it has made a world of the difference in my slushbox in conjunction w/ bigger 240cc injectors (stock 210cc injectors were severly cogged at 70K . . . had to replace them at 81K . . . now, my car is approx 85K in mileage).

I know people want proof . . . I have to clean out my engine a bit to show my MAF conversion, my AFC values (how slightly bigger MAF and injectors upset the balance of factory conservative performance perimeter, and might not see bigger injectors because it's beneath all the factory wire loom and intake manifold. Give me 3-5 days . . .

pjal84

Question baha: would the uprated injectors be necessary or are they more of a precaution to avoid leaning out, or were they simply to replace the stockers at that mileage?

bahamut

Bigger injectors are not really necessary. It's if-fy at best since I'm the only NA mirage running 240cc . . . personal test mule.

Remember or forgot to state that I do have a 2g FP (fuel pump) . . . never will run lean at WOT but possible at low throttle. The GSX FP runs normal like stock under the ecu guidance at low throttle setting and can run into lean problem. At WOT, this pump works its best running fully rich and overrunning the 210cc injectors. I don't doubt my injectors got stuck from being forced to flow more fuel.

BTW: The factory FPR can hold and return enough fuel back to the tank. There is no need to upgrade FPR, unless forced induction. WARNING: please don't go using the 2g GSX FP yet since everyone's Lancer is brand spanking new . . . I upgraded my when my FP somehow was going bad at 55K . . . fuel pressure dropped during cruising spd, losing 4-6 gallons off the guage.

Eventually, the 210cc injectors got clogged to a point (developed misfire, fouled up the plugs, and surging idle at redlight) that bigger injectors were necessary instead of paying the same amount to clean them at a shop.


Other side of the coin:

If I had a stock FP, the upgraded MAF will definately run lean throughout the powerband. Thus, an AFC is need to add correction of fuel towards the equation of counting more air into the motor.

The 240cc will make the car run rich during idle but not at WOT. Again, an AFC is still needed to correct A/F reading to insure good MPG and efficient burning. If at certain RPM, you run fully rich . . . you'll be going nowhere fast - the bogging down feeling.

Will it be enough w/ bigger 240cc in conjuction to the MAF to insure w/o the use of AFC . . . not sure. There is a good chance that a CE light will make an appearance. The ecu is confused with all the new values from the intake of air and the amount of O2 sensed to the 2nd O2. OBD2 systems are hard to fool w/o an AFC.

pjal84

Geez...so much to absorb but I'll sort through it eventually ( ). I guess my next question is, if the injectors and fuel pump are not deathly critical would simply running the AFC and the MAF be all that's needed? I figure since (if) the Lancer is running the same fuel equipment but at a higher cycle to accomodate the larger displacement, perhaps, like I said, only the AFC is necessary?

bahamut

Bigger injectors and better FP are not really necessary since I rather buy better used one than new factory stock one (get raped at the dealership).

AFC + 4g64/5g72 MAF will work. You're not getting a big performance boost, unless having more mods than I/E. If that's your only mod, you should expect an increase in MPG from the AFC tuning the MAF, better launch to a certain extent and in TQ feel, and smoother transition of speed after 3rd gear.


Here's an example:
In the UK, the base model FTO uses the same US spec 4g93 but has more HP than its counterpart. UK = 120-125 HP. US = 113 or 111 cali spec. It tells me Mitsu cut some performance from either exhaust design, cam profile, or A/F timing.

The same for the lancer. Mitsu should have tuned the 4g94 to use the bigger MAF than using the conservative 4g93 MAF (cost-sharing effort between models). I'm willing to bet the lancer could have gotten 124-127 HP (a little tweaking on the timing) w/ 135 TQ at best in conservative mode off the factory.

pjal84

Ah beautiful, baha. Thank you for clearing that up. I completely understand your repeating of the fact that more induction/exhaust (well, breathing in general) mods would be necessary for the MAF/AFC upgrade to work at a noticeable level. It just strikes me as another viable "step" in trying to extract some power out of these heavy crates. At least having the AFC would be beneficial further down the road with the more intricate mods like head work and timing changes, and heck, maybe just even leveling.

andenbre

iTrader: (4)

Dont forget that the ecm is not only watching the maf to determine the injector pulse width it watches the o2 sensors. If a larger maf is used without correction/calibration (via afc or other means) the ecm will see this in self adaptation and turn on the cel. also there is no need to use larger injectors unless you are running lean at maxmum pulse width, higher fuel pressure via pressure regulator will help in this situation but at the cost of fuel pump life.

andenbre

iTrader: (4)

I can see how a cold air intake can help performance however I think that useing an enlarged bore throttle body and a less restrictive maf would fully utilize the 3" intake, considering the maf has a 2"X1.5" restriction. I have a pet project that I am going to work onover the next 6 mo or soo, considering mitsubishi has elected to combine maf, iat, and map into their mas I have a long road maybe it will be of use to others. maybe it will be too cost prohibitive to be of use to any one, or it will fail all together. however I will be useing known good bosch sensors and a factory mitsu manual for the referance signals, maps and the such.

ROCK

iTrader: (67)

Without getting in too deep. MAF can be opened up but needs more fuel. A pump could compensate .... Injectors and AFC too. MAF on 4G94 in U.S. is the same as EVO. Yes the same, except it has a block off plate covering most of it. Cover can be removed to expose honeycomb across the entire opening. Honeycomb is there to help straighten out air flow so MAF measures more accurately. Leave it in! Modify it if you are ready to spend money on fuel delivery of some kind.
One guy called me cause his Lancer ran like ****. He had no money so he thought he would make it FAASSSST by moding the MAF. Guess what? It didn't. Modify MAF= more fuel then some tuning and away to tune it.

ROAD/RACE

http://www.roadracemotorsports.com/

andenbre

iTrader: (4)

interestingly I have inspected several Bosch mafs replaced for warrenty failures on various displacement engines from supercharged 4 cyl to 5.5 v-8 the sensor portion seems to be identcal including #s etched into the sensor portion. the only difference is the size of the tube its mounted in.



Hell, there are no rules here-- we're trying to accomplish something.
Thomas A. Edison

andenbre

iTrader: (4)

I am not modifieing my stock maf just coming up with a potential relacement system if posible that will more efficiently provide accurrate air info to the ecu. tearing out the blocking plate will do nothing but make it run lean and cause headaches, DO NOT MODIFY YOUR STOCK MAF. this is just an Idea I had to come up with for a custom peice of work for my car and maybe I can make it work . if so great if not Im out my own dough and time

andenbre

iTrader: (4)

Hey Rock while im playing frankenstien here what would you think of a air to water intercooler system similar to this only building an airbox to hold the exchanger
http://www.c32life.com/intercooler.jpg
It could eliminate alot of air tubeing, exposing less chilled charge air to under hood temps and keep things tight making for a cleaner install. probebly would add a G in parts price after markup to a turbo kit if an effective system can be designed.

ROCK

iTrader: (67)

Interesting, yes. You said it though, price would be prohibitive. Reap benefit from it on a higher boost application than a Lancer though.

ROAD/RACE

http://www.roadracemotorsports.com/