EVO III GT/650cc FIC's/100%+ IDC's!!??

[1990EclipseGSX]

My MAFt in blowthru reports richer than stock, but not enough to max out 650s at 22 psi w/ stock cams . . .

Did you use a map sensor or a wideband to calibrate your maft? I used a wideband... I'm not questioning you at all. Just confused .

My MAF-T in blowthrough read so rich I was at 100+% duty cycles on 750's @ 20psi....

I used a MAP sensor to calibrate, but my wideband also traces the estimated A/F Ratio almost exactly, so this leads me to believe it must be pretty dead on.

 

[1990EclipseGSX]

Could 22 psi just be too much boost for the turbo with 91 octane. He could have to run quite rich to stop knock with that fuel. Thanks, mark

This could be very likely. Does he have a big FMIC or WI?

 

[sweet97]

I'm confused. I also have a blow thru MAF and I have a Holset HX-35/40 turbo and run 950cc inj's with a dSMchip. At 30psi I have an a/f ratio in the 11.5:1 range on 100 unleaded. I get IDC's in the 90's nearing 100% myself. BUT if the wideband reads a good AFR then I must have a good tune. How can someone run 100% on 750's or even the 650's and not be crazy rich if the MAF reads higher than the actual airflow? Mark
PS: My friend with the evo3 is getting a wideband, not sure if he is getting the 750's also. Mark

 

[dnhieu]

i thought thoes injectors like to run at a fuel pressure of 43psi because of the 2g? i too am running gm translator and my trims are low 139 mid 114 and high at 96. i am running 650cc injectors on a 20g at 14psi and im seeing 88% idc at 7k! i was running 37psi of fuel pressure and was seeing 90%+ at 7k untill i raised the fuel pressure to 43psi. i think its the translator messing things up. im going to be switching to 2g mass and safc unless i switch to dsm link.....

 

[sweet97]

Myself and my friend run 1G's, my name here, sweet97 confuses folks, sorry! Most injectors are rated at 43 or 43.5psi except perhaps PTE's are at rated at 49psi. I'll stay with the MAFT for a while as I am computer iliterate. DSMlink is supposed to be easy but I downloaded the operating instructions and was lost!!
Since I use the wideband I am OK there but where I am confi=used is with the IDC's. Are they correct or are guys without a wideband for adjusting fuel running rich because the maft is reading more than the actual airflow? Thanks, mark

 

[dnhieu]

this is my thought. i know alot of people have had success with the gm translator but i havent and i regret that i have ever bought it. you are taking a gm part that isnt even used in a blow through mode on there cars but we put them on our cars and expect them to work like the stock mass does on our cars. i think that the gm mass sends a reading that isnt quite as accurate as a stock mass would and messes the fuel trims up. this is just my thought and when i install my wide band im sure it will be a diffrent story but i think its still going to hurt my injector duty cycle....

please correct me if im wrong....

 

[1990EclipseGSX]

Myself and my friend run 1G's, my name here, sweet97 confuses folks, sorry! Most injectors are rated at 43 or 43.5psi except perhaps PTE's are at rated at 49psi. I'll stay with the MAFT for a while as I am computer iliterate. DSMlink is supposed to be easy but I downloaded the operating instructions and was lost!!
Since I use the wideband I am OK there but where I am confi=used is with the IDC's. Are they correct or are guys without a wideband for adjusting fuel running rich because the maft is reading more than the actual airflow? Thanks, mark

It seems that there is a definite problem with MAF-T's in blowthrough configuration running rich, from what I have read and experienced. The MAFT seems to work very well in drawthough config, however.

It seems very likely that a lot of people running the MAFT in blowthrough and no wideband are running very rich, and the high IDC's are not reflective of how much air is actually moving through the engine.

DSMLink is extremely easy, don't let the instructions scare you.

 

[sweet97]

I certainly don't regret my purchase of the MAFT "denhue"(SPELLING is wrong), I apologize. I have the trnslator in my console beneath the radio and mlike having the ability to make changes from the cabin and I have become rather good tuning with just the MAFT/AFPR/CAS and my DSMchips. 11.68 @ 119mph on the Scanmaster which gets it's info from the ECU so it's as accurate as any logger that guys use to tune their motors with. 120mph traps are common place for me with my current mods. I imagine I will be going with DSMlink sometime in the future as I believe I have a low 11 sec car but can't quite get there but changing from HKS 272's to the Crower stage 4's and adding tyhe JM SMIM added 5-7mph to my traps. I am getting torque steer with an AWD! I have a wideband so I guess all is well but the airflow reading I read is not accurate since I have it in the blow thru position. My low trim is always lean, 128-140 lean but I can get the mid and high trims around 100. If the MAFT reads rich I don't understand why I get a lean low trim? The wideband is showing what I am getting for AFR's and since I am in the mid 11.xx:1 for the AFR's with 100 octane unleaded that is good! Running 30psi but I am getting a new chip that will have a quad X Karman feature since I max the 2X Karman standard feature. Doesn;'t matter if it's not accurate as I am only using the airflow reading to find the turbo's sweet spot. I am starting at a low amount of boost like 22-24psi and adding 2psi each time and doing 3rd gear pulls and logging the airflow in Hz. Once I get diminished return on the boost I will back it off 2psi and that will be the most boost the Holset will flow with the Bullseye turbine efficiently. I would like no richer than a 11:1 AFR and will get the most timing advance I can get without a knock count over whatever amount allows timing to advance, what amount of knock is that? I know after 7 counts that for each 3 counts 1* of timing is pulled. That's what I have been told. I believe 3 or 4 counts will still advance the timing. Can someone clear this for me? Thanks.
Since I run a ColdAirIntake even with a 4" compressor inlet doing the MAFT draw through will not work. I am a firm believer of CAI's. I even cover the intake pipe with header wrap to keep the intake air cool and cover the upper IC piping also. My FMIC is a Spearco 2-221 bottom to top flow capable of flowing 1080cfm and capable of supporting 760HP according to Spearco. Can't do a lot of back to back runs though as because of it's size it will heat soak.
Question, are my IDC's correct or anybody's if they are running the MAF in blow thru with a wideband and hitting a specific AFR? I get IDC's in the 90's at 30psi with the big Holset compressor, supposedly to be capable of flowing 70lbs/minute. I will let you guys know what my friend comes up with when he gets his wideband. He is getting the AEM wideband due to it's 2 1/16" shape to fit his pillar pod. Not sure if he is still getting the 750's. mark

 

[1990EclipseGSX]

The IDC's are always correct. The airflow is what is incorrect, but if you are using an AFC or MAFT to tune with, the airflow will always be off...

If you are seeing 90% duty cycles at 11.5:1 AFR your injectors are really pretty much maxed, unless you lean out the tune some more or raise your fuel pressure.

When your friend gets his wideband, I imagine he will end up having extremely rich AFR's, which will explain the high duty cycles. If this is the case, and leaning out the car makes it knock, he will have a few options... He can turn down the boost, or get a WI kit, or get some larger injectors to run that rich without maxing the IDC's.

 

[sweet97]

OK Chris. So the ECU "sees" a high airflow and adds more fuel when it's actually not needed then. So tuning with the info from the wideband negates the airflow reading?
Strange though that with his WOT knob on "0" he got no knock but turning it 1 click lean to "F" resulted in 10 counts of knock! That 91 octane must make a big difference compared to 93 octane, more than I would have imagined.
My motor seems to like the 100unleaded as much as the 110leaded! That was just one tank of the 110 but the settings were very similar and times and traps similar.
My base fuel pressure is at 40psi now but I think I will raise it to 43 to see what happens to the IDC's.
Once I get the quad X Karman chip I will be able to read the airflow, accurate or not, it will be used as a guide to find my turbo's sweet spot with the somewhat restrictive turbine housing. Knowing what I do now I would have gone full Garrett, just don't know if T3 or T4 would be better the next time I am turbo shopping! Thanks for the help and info all, mark

 

[compression]

If this is not the correct forum let me know and I will move it. A friend bought the EVO GT big 16G and a set of 650cc FIC's. At 22psi he is getting over 100% IDC's on his logger. His trims are right around 100%. Fuel pressure is set at 40psi base, hose off.
When I ran an EVO I had 550's and ran right around 100% IDC at 20-22psi so I thought 650's would be great for him. Now I'm confused. Does the GT copy of the MHI EVO flow that much more air? He has the MAF in the blow thru position. Also has a KEYIVER chip compensating for the 650's. Has the MAFT base set on 5 to get the trims at 100% which is leaning the inj's which should lower the IDC's wouldn't it? Has me stumped. Suggestions please? Thanks, mark

he has the maft set for 450cc's right?

 

[sweet97]

I stated in the original thread you quoted that he had to set the BASE on "5" to get his trims to 100%. A "5" is leaning the BASE as "5" represents 480cc inj's. I would think leaning the BASE would allow for lower IDC's. KEYDIVER said his chips, when used with a MAF-Trabslator often required a setting of 470cc inj's. Mark

 

[Baron4406]

My EVO 3 GT w/550's is only hitting 75% IDC at 20 psi, however I have a 255 Walbro w/Aeromotive FPR and a front mount. 93 octane.