03whitegsr

iTrader: (8)

I tried to search for this in a couple different threads, but I found a couple different answers. Can somebody provide some clarity here as to how I can (first) log the GM IAT and (second) verify my GM IAT sensor is reading correctly for the speed density patch.

Going back through the thread on the speed density patches, the table in the patched ROM from Phenem (Tephra V6 thread) matches the table from the thread below.
https://www.evolutionm.net/forums/ec...y-patches.html

That thread says to patch the speed density rom with Mrfred's MAT patch. Mrfred's MAT patch table has different values then the IAT table in the speed density patch. The IAT table that comes up in a stock rom with the speed density xml file is differnent then these other two tables as well.

I would obviously want to log the value that is actually the value used for fuel and timing correction. It would seem if I do Mrfred patch along with leaving the Phenem patch ROM values in the Speed Density table, I will log different values then what the ECU is actually using to calculate fuel correction?

Is the original patch intended to log the manifold temps through MUT11, MUT3A, or as Mrfred does through MUT09?

For 9653 based ROMS, which table will actually be used for the intake temps in the speed density patch? The table at address 9a8e or the table from MRfred's patch at 2d78? Is this with or without Mrfred's patch implemented?

03whitegsr

iTrader: (8)

Mrfred answered this elsewhere, but maybe this will help somebody else out and be simple to find.

96530006 is a bastard child that does not need the mrfred MAT patch for speed density. The IAT table is changed in the SD patch.

Log the GM IAT through MUT11 once you have completed the SD patch.

l2r99gst

iTrader: (2)

If you are using the fuel temp ADC, then the mat patch is required. Just wanted to clarify that.

03whitegsr

iTrader: (8)

Mrfred is saying it is not required on 96530006 since the Fuel temp ADC channel is not used normally in that ROM.

It sounds like there is still confusion here. I'm not using mrfred's patch and it seems to be logging correctly. Obviously I haven't been able to verify that the car maintains AFRs across a temperature range yet though.

The table that comes pre-patched in the 96531706 ROM is different then the table mrfred posted for the GM IAT sensor though, which still concerns me.

l2r99gst

iTrader: (2)

That table values are the same...the two tables are just slightly different in size so it appears that they are different.

Either I am confused then or mrfred mispoke then...because it is my understanding that when using the fuel temp adc for logging MAT, you need the MAT patch applied and the MAT scaling table for that patch populated.

That is how I did it for all other versions of 96530006 SD, so I don't think anything has changed in V7.

03whitegsr

iTrader: (8)

Interesting.

When I took MrFred's xml addresses and look for the tables in the 96531706 ROM that is in the TephraV7 thread posted by Phenem, the tables are not in the ROM. The tables in the 96531706 ROM match the tables of a stock ROM.

However, the table in the Speed Density section for the IAT scaling (address 9a8e) is different in the patched rom than a stock rom, so changes have definitely been made to that table for the speed density patch.

That table does not match the table MrFred posted. I charted it out and they are not the same, regardless of table size.

l2r99gst

iTrader: (2)

The IAT scaling for the SD patch is if you are using the MAF IAT input for MAT. The MAT patch scaling is if you are using the fuel temp adc for MAT. That's my understanding.

Edit: Also, I didnt check for myself, but mrfred verified that the two tables were identical when mapped over each other using Excel.

03whitegsr

iTrader: (8)

That's what I figured too, but that ROM was supposed to be pre-patched for a GM IAT.

l2r99gst

iTrader: (2)

I can't speak for that...maybe ask phenem where he got the table data from for each. I do remember over time there were a few different scalings as it was refined.

03whitegsr

iTrader: (8)

I was wrong. Not sure what I charted the first time that gave me the wrong values before. The table Phenem has in his patched 96531706 is the same as the table used by MRFRED. Mrfred's patch is not applied to the 96531706 in the tephra V7 thread though. In the title is the address where each is found.

golruss

iTrader: (3)

For SD on the 965.... rom using the fuel temp input should the IAT scaling be in degree 'F' or 'C' ?

l2r99gst

iTrader: (2)

It depends on what scaling you are using for the table. You can have it in whatever scale you want.

mrfred

iTrader: (50)

I initially thought the 96531706 MAT scaling was wrong because I didn't notice that phenem was using deg F for all his temperature scalings.

03whitegsr

iTrader: (8)

Ok makes sense as to where that came from as I had seen other threads saying it was wrong.

What about the overall issue of should your patch be implemented or not on 96531706?

Also, for datalogging, are these correct scaling equations?

1.8x-40 = degF
x-40 = degC

mrfred

iTrader: (50)

Those are the correct scalings for farenheit and celcius. MAT patch is not needed for 9653 SD ROMs. IAT becomes MAT with the SD patch on this ROM regardless of whether the fuel temp or IAT ADC is used.