Chrome V3, need a place to organize my thoughts

[Jeff V.]

Could you download the tables from a GM vehicle and see if it's possible to adapt them to the Mitsu software?

[mjannusch]

I do have tables from GM - but how sure are we of the units on the Mitsu side?

[Monochrome]

I’m not convinced the MAF is the big restriction everyone has been claiming for years. There was a hardware limitation to how much it could count but Adam solved that with his MAFs.

The EVO guys put down 650+ on a MAF that is physically smaller than ours. I was able to make over 450whp with the stock MAF and no vacuum drawing inside the intake pipes pre-turbo.

I love Matt Monnet but I now know his claims about the stock MAF were false. I ran mid-12s with more boost, octane and (most importantly) a lot more timing advance.... This is what the ARC2 and MAFT give you. This is why Matt was able to pick up 10mph in the 1/4 mile. Not the MAF restriction.... simply from more timing advice. I get it, the guy was trying to sell a product but the claims were falsely represented.

[Monochrome]

[quote=""mjannusch""]I do have tables from GM - but how sure are we of the units on the Mitsu side?[/quote]

I’d have to teach myself the GM ECU processing language in order to see how the scaling is setup.

Then we have to figure out how to convert a 12V MAF to a 5V one.

Then we have to see if the ECU can handle 12000 pps triangle wave vs the stock MAFs 3000 pps square waves.... This part Adam and I were able to do.

I’ve played with the slot MAFs and couldn’t get it to work. All under the false guise that the preturbo MAF is somehow restrictive.

[mjannusch]

I made 540 awhp on the Evo MAF easily, and like you said - it should be more restrictive than our stock MAF. From an electronic perspective, at what point does the stock MAF start dropping counts?

[aaronatstate]

I would agree the MAF is not the restriction either. I have the Evo MAF and have no issues (Adam just puts the Evo guts in a 3/S MAF right?). Isn't the throttle body smaller than the MAF anyway?

[Jeff V.]

The GM tables are well understood by sources like HP Tuners. I doubt you'd have to dive into GM assembly code. It's a 5 volt hot wire sensor, so voltage shouldn't be a problem and there are no pulses to count. Mitsu started switching to this style of sensor in 2004 with the 6G75s, so the logic for those is available.

[mjannusch]

[quote=""Monochrome""]I’d have to teach myself the GM ECU processing language in order to see how the scaling is setup.

Then we have to figure out how to convert a 12V MAF to a 5V one.

Then we have to see if the ECU can handle 12000 pps triangle wave vs the stock MAFs 3000 pps square waves.... This part Adam and I were able to do.

I’ve played with the slot MAFs and couldn’t get it to work. All under the false guise that the preturbo MAF is somehow restrictive.[/quote]

The GM ECUs have their MAF frequency map scaled in grams/sec. If I remember right, the slot MAF outputs 1.5v square waves. Or at least mine does (LS7 Z06 MAF).

I designed circuits to do a div/3 or div/4 on the frequency and output a perfect square wave regardless of what type of pulse is input. Can also scale the voltage output to whatever is needed. Not really a problem there. /4 is going to drop it into the stock MAF frequency range.

[Monochrome]

[quote=""DCIV""]So draw through or blow through just can’t happen though? Have you talked to the DSM link people? They have that option.


Coop[/quote]

The “Blow thru” idea needs to go away... You’re taking a Hotwire sensor and exposing it to high velocity “hot” air. So few people get it to work and of them none can achieve stock smooth drivability. The resolution in the low airflow areas isn’t good enough.

I’ve got a lot of professionally tuned MAFTs setup in both blow and draw with idle issues and low throttle cruising issues. Most people just accept this under the pretense that their car could potentially make more power.

The issue with these piggybacks is the lack of resolution. Different volumes of air trigger little to no change in the pulse signal it sends to the ECU. Closed loop basically takes over and keeps the car idling as best it can. The ISC is clueless and because of this we lose the real time ignition timing adjustments to give us that stock smooth idle.

[mjannusch]

Agreed that blow-through is just simply not accurate nor reliable.

[Monochrome]

[quote=""mjannusch""]The GM ECUs have their MAF frequency map scaled in grams/sec. If I remember right, the slot MAF outputs 1.5v square waves. Or at least mine does (LS7 Z06 MAF).

I designed circuits to do a div/3 or div/4 on the frequency and output a perfect square wave regardless of what type of pulse is input. Can also scale the voltage output to whatever is needed. Not really a problem there. /4 is going to drop it into the stock MAF frequency range.[/quote]

Yes but again you lose the low airflow resolution which is what we need for stock drivability and smooth idle.

25 g/sec in their hex code doesn’t necessarily mean the same in ours.

The GM code does things so much differently than ours too. We don’t have a fuel table like theirs (and most stand alones). Our “fuel table” is nothing more than a 3D correction factor based on MAF pulses and RPM.

[Monochrome]

[quote=""mjannusch""]I made 540 awhp on the Evo MAF easily, and like you said - it should be more restrictive than our stock MAF. From an electronic perspective, at what point does the stock MAF start dropping counts?[/quote]

About 2400 hz.

Adams new MAFs have yet to find a limitation and he’s made a lot more power.

[Monochrome]

[quote=""Jeff V.""]The GM tables are well understood by sources like HP Tuners. I doubt you'd have to dive into GM assembly code. It's a 5 volt hot wire sensor, so voltage shouldn't be a problem and there are no pulses to count. Mitsu started switching to this style of sensor in 2004 with the 6G75s, so the logic for those is available.[/quote]

It’s even simpler than you might think. I learned a lot disassembling the Padjero EVO ROM which is true SD stock. Replacing that lowly 1bar MAP sensor with one of the new 5V Hotwire sensor MAFs would probably be the best solution.

[ChargerX3]

[quote=""aaronatstate""]I would agree the MAF is not the restriction either. I have the Evo MAF and have no issues (Adam just puts the Evo guts in a 3/S MAF right?). Isn't the throttle body smaller than the MAF anyway?[/quote]

IM pretty sure he does. I wonder if he has to mess with the stock 3s scaling though as flow should be unaltered?

[DCIV]

Grrrrr. I agree with you all. Sadly this also means I need new intercooler pipes to be able to do this.

Maybe I will put that on the list.


Coop

[ChargerX3]

[quote=""DCIV""]Grrrrr. I agree with you all. Sadly this also means I need new intercooler pipes to be able to do this.

Maybe I will put that on the list.


Coop[/quote]
But...

[Monochrome]

[quote=""ChargerX3""]IM pretty sure he does. I wonder if he has to mess with the stock 3s scaling though as flow should be unaltered?[/quote]

I’ll get into this in a future post. Basically a lot of what we believed 8-9 years ago is wrong.

[Chris GTO TT]

[quote=""ChargerX3""]But...
[/quote]

[ChargerX3]

[quote=""Monochrome""]I’ll get into this in a future post. Basically a lot of what we believed 8-9 years ago is wrong.[/quote]

Oh great. Thats what i get for trusting you all these years. :ick:

[Monochrome]

[quote=""ChargerX3""]IM pretty sure he does. I wonder if he has to mess with the stock 3s scaling though as flow should be unaltered?[/quote]

Not exactly. It’s an OEM MAF from another Mitsu and after disassembling the ROM for that vehicle the scaling for that MAF is the exact same as our stock ones.

So you guys running EVO MAFs have been duped and the setups you’re running for them is wrong.