unfortunately boni, i don't know how certain fpr's will work on a turbo setup since i'm still sitting here NA and can't really experiment myself. zlancer's turbo setup was from rpw and they have in their kit 300cc injectors with a boost sensitive adjustable fpr and uses the safc. rrm's setup is 240cc injectors with vortech fmu and stock fpr and no safc. both use a 255 walbro. i don't know for sure, but i think that you'd only be able to tune the safc where there's boost if you get the vortech fmu. only because with the stock 240cc you can't really use the safc without raising overall system pressure. if the vortech is adjustable, you can tune negative on the safc if you set it to push more fuel under boost. but a few posts back we kinda think that at 180whp, the 240cc injectors are either close to their limit or well beyond. then again, RRM's setup is tried and true. i think with larger injectors with either fpr (vortech or rpw) then the safc should be effective.

the rpw fpr is a bit different as the overall fuel pressure is adjustable and not the fuel ratio under boost. this is what i use on my NA app and raise the system pressure and tune down with the safc. rpw uses 300cc injector with this fpr and an safc to tune their turbo kit. i guess it comes down to what kind of fpr you're gonna use and if you're gonna stick with 240cc injectors. i'm trying to get 320cc injectors from a celica gts and see if they fit.

zlancer said he came across a problem with the rpw fpr. i dunno if he solved the problem cuz i don't exactly follow the turbo threads, but you might wanna shoot him a pm about it. also, you can pm mitsiman or email RPW about their setup and i'm sure they'd help you. overall, if you can push enough more fuel at the same IDC than stock, you can use the safc.

 

Also though, since all Lancers are now Cali spec. cars, with no Fed. spec. running around (as opposed to the Mirages, who we don't know any CA or CA bought cars using an AFC), the ability for an AFC to work may only be applied to cars in the US. In Australia, the cars may very well be able to be tuned with any run of the mill AFC.

 

whaddya know! excerpt from "Tunerology" in the January Import Tuner.

"In the case if the EVO, the frequency type mass air sensor is so sensitive that by increasing the airflow by adding a high-flow filter will actually make the mass air sensor send a signal to the ECU to lower the boost pressure due to the air flow increase. Using a piggyback computer to lower the frequency would lean out the fuel curve to get the car to boost up but at the same time you run the risk of your car running too lean. Solution: eliminate the OEM boost solenoid to run the boost control separate from the ecu and go to larger injectors to lower the frequency of the mass air using the piggyback unit."

hmmm, maybe they were right about the airflow sensor thing. but then again, our ecu's weren't meant for boost so maybe they just hold tight IDC (lol, stubborn me gotta stick to my idea til proven wrong) since we don't have a boost solenoid for the ecu to control i think i've posted before that turbo lancers see a high of 1320hz which is way beyond the measly 958hz that i've seen (though i haven't checked lately). so our MAS do see the higher counts, its just that i still don't understand how they react. see, you would miss stuff like this if you didn't keep magazines in the bathroom!

 

you think RPW would just let us have one to play with? hehehe

 

Amazing post guys.

 

I don't know if it's a safety feature for an EVO since it has a more aggressive motor than a normal 1 or 2g DSM. Remember the EVO MAF is the exact same as the 2g DSM, 3K GT VR4, and the Evo 4-6.

It's interesting about the FPR being the culprit. The turboed G93 guys never informed us about their FPR messing up the AFC . . . could be a cali spec safety feature if Mitsu (highly possible) sharing the same FPR but designed it a bit different in fuel delivery.

Also, there will come a point when the stock MAF will bottleneck counting air that went beyond its normal, highest perimeter from the factory. Basically, no matter how much fuel from the AFC or FPR pressure . . . the stock MAF can't compensate for higher airflow rate.

EX: you have a boost gauge that max out at 22 psi, but you hit a spike of 26. The gauge will inform you its pegged at 22 an no more.

With a 501 MAF, you're airflow count is way higher since it's used in the NA 6g72. We all know 6 bangers needs more air than a 4 banger.

 

rhyzin,

I just realized that our results on two similar engines are exactly pointing to the opposite direction. I'm starting to think the ecu setting from the factory is the biggest variable.

I know by default auto tranny cars are a bit rich right out of the factory, and its weight issues vs manual is pretty much a thing of the past since the mid-90's. Mine was 80lbs heavier than manual from the sales brochure.

Your AF ratio is good at WOT, and there is no need to hit higher than .96. How's your MPG? The huge postive correction on the LO is nagging me, unless the bigger MAF is leaning out the O2 (more likely since the Lancer are using stock 240cc and the ecu factory tuning). I'm trying to imagine the AF ratio stats on a 3g GS/RS w/ a bigger motor w/ the same injector cc's and MAF setup.

Also, I do know the 2g GSX FP runs like a normal FP during regular driving, but it really shines at WOT for NA cars.


BTW: can you ask RRE/RRM guys if they can provide you stats on the fuel trim ratio for a stock lancer during normal operation, not WOT? We need to figure out how much richer from the factory tuning and vs manual to auto tranny. If we can figure this out, it should cut half the clutter that we're thinking of. It's getting there, just a few more variables to crack.

 

i haven't really gotten around to it before, but here's something else i've been thinking about. these graphs are just to illustrate and are based on what i think i know. if they're wrong in any way, please correct me.


so here's stock fuel delivery vs correction (0%). fuel pump flows less at higher pressure(higher rpm) and correction is 0% on a stock car.



there's fuel delivery if you had a pump that had the same lph rating but kept the fuel delivery up at higher fuel pressures. corrections would change where the difference between the two pump start. you would then start to add negative correction at higher rpm.



so here's where you upgrade the flow of the pump as well to say, maybe an eclipse 2G pump as i have. you would have an initial negative correction across the board as well as an increase as you climb rpm.


and here's where i'm at right now. you start out negative and end up going upwards toward positive. what happened here is that the restrictor of the MAS has been enlarged(501 MAS). by design, if you enlarge the diameter of piping, you're bound to need less fuel at low rpm(since air will move slower), and need more fuel at high rpm(more air faster).

a comparison of the 2 MAS is that the chamber at which air is metered is the same. what is different is the air bypassed around this chamber. with a larger bypass chamber, less air would be counted through the metered chamber, hence, a lower Hz count reported by the MAS. the original cars were engineered to take this into account and make the correct adjustments. ours do not. therefore, the Hz readings are taken for true.

now take the relation between Hz and IDC. if say we hit a wall at 300Hz on a stock MAS for example, the 501 would read maybe 250Hz. this would mean i have 50 more Hz of space to give a positive correction on the safc. if the airflow reading reaches a certain Hz(with other compensation by other sensors such as IAT and barometric sensor), then the ECU would figure a certain IDC and even though the MAS may read higher, the ECU doesn't increase IDC. i figure if the ECU could read true IDC, it would've been a monitor in OBD2 and show up as an option on my datalogger.

and this is a possible theory on why i have positive correction on my safc. i could be pulling stuff out my *** cuz i'm running out of ideas.

 

Question for you guys on this stuff... are the MAS's mounted upstream (negative pressure) or downstream (positive pressure) of the turbo relative to the intake, in mitsu's or does it matter. My brother and I have been running into some issues as far as the MAF sensors he's trying to work with on his Turbo MP3, first the sensor was too huge (made for 500 whp WRX) and now the sensor is too small (maxes out when he revs at idle) so I"m looking into a possibility of using a turbo eclipse or larger engine Mitsu MAS/MAF to swap in so that we can get him running. Although reading through the thread again I'm seeing more about frequency based output, and not just a pure proportional voltage which is what the systems he currently uses output. We are trying to mount it upstream (between turbo and intake) for better accuracy and so forth, but are not sure if the MAS's from mitsu's or so forth will work in that application.

Any thoughts?

 

what type of MAS does the mp3 use? mitsu, until 04, use a karmann vortex MAS which are read in Hz. it could be converted since i see lbs/hr from OBD2. none of the ralliart drivers have any idea what theirs are and many of the new models are using this new type of MAS. i really don't know of any other car maker using a MAS compatible to the karmann vortex type. i'm thinking the possibility of a translator if you wanted to use a mitsu MAS.

mitsu MAS placement is at the end with the filter. havent seen any other configuration. you could look at a mazda MAS from a larger displacement engine. maybe from the 3.0L M6 or tribute, or maybe even the rx-8.

 

Yes, the MAF for Mitsu is Karman, not hotwire like most other companies like Ford (ie like the SVT contour or Cobra), GM (like the Vette), Nissan (from 240 to 300z), and etc. Also, Mitsu MAF cannot be moved around like a MAP sensor. Otherwise, the air count will be so wrong that it will throw a CEL and stall.


Karman is a bit easier to tune, but it's harder to gain HP.

Hotwire is similar to above, but it's potential is a bit better w/o going through a honeycomb to straighten the air.

MAP is the hardest to tune, but you get the highest HP gain.

 

Damn, a bit early in the morning to start thinking about graphs.

1st graph: It's so true at stock everything for Mitsu's SOHC. It runs out of steam/breath towards the top end of the rpm; thereby, the fuel delivery is retarded too.

Second graph: What if (graph-wise) you don't put any correction on the fuel after jacking the fuel PSI for a stock FP?


BTW: I'll think on the 3rd graph soon and edit my post.

BTW II: What about PJ and Uranium9v w/ their cam? Do they have the PDA? Both of them gone a bit off the traditional route, but we might need more baseline results to balance out the experiment.

BTW III: can you ask RRM/RRE guys to try out the bigger MAF on their drag lancer project. HP gains will be better than the stock

 

I couldn't find what kind of MAF is on the MP3... About all I know is it is VERY similar in appearance to ours, runs a honeycomb section through it like ours, has a bunch of asian script on it, and gives an analog (I believe) 0-5V signal.

Don't know how much/what the helps with .

There is a company that will actually manufacture a true venturi MAS for you based on your application. That way you can put it AFTER the BOV on a turboed system etc. They are also scalar and can build any size you'd need etc. If you are interested in it let me know and I'll get more info.

Later.

Steve

 

it seems our last MAS upgrade would be that of the EVO 8 #399. seems to be same plug size, 7 wires, and same shell as the 605 or 501. saw one yesterday on an evo when i went to get my car dynoed. i got 116hp@5900 and 123tq@4500 with an sae correction factor of 1.02. i think there was a few extra ponies above 6k as the guy only went to redline and i'm sure he fell short of 6k by a bit each time. everytime he got closer to 6k, my peak hp was where he stopped.

i guess i'll take a visit to a protoge board. my friend has a mazdaspeed and i'll ask him a bit.

for hot wire, there's 2 separate strings inside where volume is calculated by the difference in temp of the 2 strings. they also either have a screen or honeycomb of sorts, but the 2 wires should be able to be see from the outside.

a karman type sensor will have a triangle in the middle of the sensor (that brown piece). that splits incoming air and causes them to form vortexes as they pass. a sonic sensor then sends sonic wave through the vortex and depending on the size or number of vortex, returns a signal back. kind of like echo location. this info is digital, but i'm sure it is converted to something else before it goes back to the ecu as OBD2 reports air volume by lbs/min.

 

Actually the FPR is what is giving me the problem.. had my afc corrected for the most part to see if i was able to solve my fuel cut, when Jr. at turbotrix told me that my FPR was set at a static 1:1 rate when in fact it was supposed that the FPR was a rising rate 1.7:1. Which in turn makes sence on why every time I hit boost or even around -2-3 HG is where im losing my fuel pressure.

edit: just read this post now thats why im replying from the earlier said, but just want to clear things up because i think rpw doesnt give rising rate fprs i think that they are assuming that a static rate will work