I guess I'm just confused still of how it knows what 400 and 300 is and the difference between these values on two different MAP sensors? Do the end values on the table correspond to certain input voltages or something?

Largest value in table = 255 on the ADC input?

 

You are changing the scaling and then retyping your break points, so the raw (hex16 if you like - try changing it) values at the same manifold absolute pressure are different for different sensors. You could scale it all raw if you like, but Ecuflash can display it nicely with human units.

Largest value is 1023 because it is 10bit ADC.

 

what will I need to do with a stock set up sensors wise to implement SD? The type, make and where to wire it would be greatly appreciate.

Thanks!

 

VE= Load/(MAP*(298/(273+MAT)))

Is MAT the temperature the air mass is reading or the intake manifold air temperature?

 

I'm calling IAT the reading that all Evos have in the MAF sensor, and MAT the inlet manifold air temp that Evo IX JDM/UK have and others have added.

 

John, which is the MUT address for stock MAT in JDM ROM? And the formula is the same for MAF IAT?

Thank you!

 

Request BD. Same as IAT formula.

 

Is it scaled or not?

 

Sorry I don't know what this means.

 

I think he is refering to how there are usually two different temperature addresses for each temperature measured.

Coolant temp (can't remember the formula)
Coolant temp scaled (x-40)

 

It is non-linear, I only usually log it on my own logger for my Pocket PC, for this I use a linearisaztion table in the program to straighten it out. There is no linear logging as standard for the MAT sensor, you could change the MUT table to give one I suppose.

Now I have IAT=MAT it can be logged on the IAT channel though.

 

03whitegsr exactly.
I noticed that the address “BD” (6A1B) in MUT is not the MAT(?). The value starts from 100 (cold) and while the car is warming up the value goes down instead of raising!
I used the same formula of MAF Air Temp Scaled.

 

It is not linear, and it is inverse - thermistors usually are. You need to have a lookup table to make sense of it, or a polynomial, or you could log the "scaled" MAT by changing the MUT table. Personally I have only used the lookup table method, so I don't have the address handy.

Note that if you are using MAT for SD you should use code or wiring to get the MAT into the IAT channel since this will then compensate the load and the IPW correctly. You'd need to rewrite a lot more code to get your compensations done for MAT unless you do this. Since most doing SD want to remove the MAF sensor, that is why I went for the simple substitution method.

What are you trying to do? Just log MAT or go to SD?

 

Mrfred, with regards to JCSBanks post above, on 94170015 have you recoded the ECU to use the fuel temp input? Or do I need to wire in the GM sensor into the IAT input?

 

I've written the patch with the intent of wiring the GM IAT sensor to the fuel tank temperature ADC input and applying my MAT logging patch. I thought it would be easier this way because as long as the MAF sensor remains connected, it makes it possible to go back and forth between MAF-based and MAP-based control with just a reflash whereas if the GM IAT sensor wired to the IAT ADC input, not only is a reflash necessary to go between MAF and MAP control, but the stock IAT sensor needs to be reconnected or some sort of toggle switch needs to be implemented.