http://www.dsmtuners.com/forums/tuni...shing-faq.html

The MAF scaling posted in the first post at the bottom for the Evo is different to what the 8 ROM has and also THE 2g scaling is different to what the Evo 1-3 ROM has. Is some sort of scaling being applied to the decimal value?

Apparently, it seems there are 3 different MAF scalings for the same MAF.
95 2ga
98-99 2gb
Evo 1-3

Who knows what the 96 or 97 ecu had for values.

I think that once I get my 660cc injectors and 190 walbro in, I'll go through the MAF scaling routine, get some numbers, and make a pretty little graph. I'm an engineer, I like graphs.

That seems to be the biggest issue as of late. Either the MAF's are calibrated differently from year to year, or the CPU's need different values to do their math internally but I don't think that's it really. It'd be cool to have a way to cross reference the MAF part# to see what year its from. That'll help a little I'd imagine.

On DSM ECU, the accepted scaling for the 2G is the same in Hex as the Evo 1-3 scaling. I guess this would be the same as the 95 2G.

I am going to download a 99 2g ROM and look at the hex values for the MAF scaling to see if it is actually different.

Okay, here is why the scaling values are different. In the DSM ROM the MAF scaling is Airflow 8 which is x*321/256 wheras for the 8 XMLs it is Uint8 which just uses the decimal value.

This is what is messing up the MAFscaling when the 64 adder is added and the 140 subtracted.

Again, the one I posted is correct for an 8 XML.

Good eye. The evo5base.xml has Airflow8 as default and the evo9base.xml has UInt8 as default. Who ever is in charge of the base files should change them to match so everyone is using the same units. Sorry I posted bad info previously.

So it seems we are FINALLY getting a few more of these bugs worked out, especially with the MAF. Now if we knew the MAF adder address for all the ROMs, we wouldn't even have to mess with adding and subtracting adders ourselves. But that's just the lazy in me talking.

If you send tephra an email with the 99 eclipse bin file and tell him the maf adder address, he said he will try to find it in the evo rom.

Tephra at gmail.com

How are you flashing this ECU?

I noticed this is in the ECUFlash sectino, but as most of you, my car doesnt have a OBDII connector.

I'm not flashing it, I just downloaded the ROm from ceddy's thread on dsmtuners.com. Search for 'first reflashed 2g dsmtuners' on google, that should help you track down whats required to reflash the 98/99 2G ECU's.

Since I cross referenced the 99 eclipse ROM data in its RAW form (hex), I have the car running better than anything else I've tried thus far. I'm basically just editing my injector scaling to try and get my trims in the ballpark. I'm certain this car has a decent boost leak somewhere so until I get that confirmed I'm just wasting my time with airflow adjustments. Thanks for everyone's help on this topic. Decent headway has been made already.


EDITED: corrected MAF ADDER
So I have set my MAF scaling to DECIMAL (uint8) so now if I want to make adjustments in the Evo8 ECU I just need to add the MAF Adder DECIMAL value of 140 (8c hex) to my scaling values then calculater the percentage adjustment I want to make.

Example: to add 10% in the 75Hz area, take the decimal value of 132, add 140 to it to get 272. Then multiply by 0.10 to get 27.2

Then subtract 27 (rounded) from the original decimal value of 132, so my new value for 75Hz would be 105.

(original MAF scaling value+ MAF adder)*percentage change= correction amount

(132+140)*0.10= 27.2 (rounded to 27)

original MAF value - correction amount = new MAF scaling value

132-27= 105

This seem like the best practice to everyone?


If so, add this to your ROM XML file and you can just use this scaling so you can edit your MAF Scaling with EASE.

You may need to change the ENDIAN to 'LITTLE' if you are using an older version of ECUFlash that requires it.

I think the question actually refers to how do you flash the evo8 ecu while it is in the 1g because a 1g doesn't have an obd2 port or flash port. The flash port is easy, you just add a pin and wire to the reflash pinout (87? I don't remember off the top of my head) and either add a flash port since it is only one wire or just stuff a wire right into your cable. As for the data that passes through the obd2 port I have no experience but I assume you just wire one in and it can't be that hard.

So Jack of Trades, what are you running the Evo 8 ecu in? I'm running it in a 97 Talon. I just went out and did a little street tuning. I'm creeping up to 17psi with my small16g, but it pulls hard. My only problem at the moment seems to be a slight break up if I stomp on the gas. I'm going to pull the plugs once the car cools off and see if they're fouled. I ran a can of Seafoam through the intake last week and never pulled the plugs so check them. Being that my WBo2 is acting up, I'm thinking everything from the intake on out is covered in soot.

At this point I'm runninng 91% IDC at 6500RPM on the stock 2g 450cc injectors. I'm waiting my new injectors seals to come in the mail. Then the PTE 660cc and the 190 wally go in and the boost gets turned up. :D

I'm loving this Evo 8 Ecu. As much as I've been fighting with it, it's starting to pay off. Hopefully, I'll get at least one 1/4 mile pass in before the end of the season.

You add and OBD1 ports reflashing wire to pin 79 on the Evo8 ECU. The k-line wire (pin 7) on the OBD2 port needs to connect to pin 69. You also need to connect pin 16 on the OBD2 port to +12v constant and ground pins 4 and 5. HERE is a diagram.

I'm running it in a '90 Mirage with a '90 4G63 engine swapped in her with a 2G MAS. I have plenty of work to do on this thing so right now I'm only focusing on closed loop tuning. WOT tuning is still a ways away for this car.