IAT 2 Timing correction tables e67 ??????

[Y BE AVG]

Can we get access to the IAT 2 spark correction tables on the ZL1 e67? Or have I just been missing them?

[Rhino79]

They aren't in some os's some they are. I ran into this today on OS12653669. Major timing rape when in boost!

[GMPX]

What E67 OS has them shown? If they've been left out it's an oversight.

[Y BE AVG]

The operating system that i need them for is the ZL1 12653669

[GMPX]

What E67 OS has them shown?


The operating system that i need them for is the ZL1 12653669
I'll await Rhino79's answer :mrgreen:

[Y BE AVG]

I'll await Rhino79's answer :mrgreen:


While your waiting for his answer.....
Can we get this added, ive got four ZL1's sitting here right now that this affects. It would be much appreciated

[Rhino79]

Ross, I pulled every Zr1, Zl1, and Ctsv file I could remember customer names on and that table is NOT in any of them, and I swear to god it used to be. There used to be IAT and IAT2. In the calibration ID section at the bottom where normally it lists calibration options, all my e67 are blank too.

[DrkPhx]

I've never seen IAT2 spark tables in any of the E67 files I've done. Can it be added?

[ScarabEpic22]

Ross, here are the TBSS ones that have the IAT2 spark table. (Everyone is talking about B5147 IAT2 Spark right?)

2007 TBSS: 12611938
2008 TBSS: 12618164

Missing in 2009 TBSS: 12630465

[GMPX]

I don't think that is for IAT sensor 2 (yes, it's badly labelled).
I can't recall any specific table for IAT sensor #2 spark correction, I am sure they use it for intercooler pump control only.

I think you will find in the earlier OS's before they used variable axis points it was fixed to that smaller range and they had to add the second table, in the later OS's they dropped it back to one table and expanded the range from -40 to 140 °C.

[Y BE AVG]

I did a test on the dyno yesterday to verify our problem. Commanded timing 16* pulled back to 9* at 6000 RPM result was 507 HP. took an extra IAT 2 sensor an plugged it in to the harness in free air...No timing was pulled result 672HP. left it that was to finish dialing in the car. 769 hp right now and still going, but I can't deliver this car this way. It has been converted to a Kennebell and they run 170f-200f with 16-20 psi boost. Heres a little clip from yesterday when we were chasing belt tension issues.

http://www.youtube.com/watch?v=aXjNSGfc7d4

[ScarabEpic22]

Y BE AVG, looking at my IAT2 table, it is only for 248F+ so it wont help your issue around 170-200F (still be in the main IAT table).

I think your issue is elsewhere related to the IAT #2 sensor calibration as it sounds like that "fixed" your problem. I dont know where/how the IAT2 sensor ties in, I believe it goes in the s/c so the ECM knows exactly what the incoming cylinder air temp is.

Ross, I agree with you. I noticed it before, but just realized it again after your post and looking at the tables again. This "IAT2 Spark" table doesnt have anything to do with IAT2, it is simple an extension of the IAT Spark table. Looking at the 09 CTS-V OS, the IAT Spark table has the range of the IAT and IAT2 Spark tables in my 07-08 TBSS OSs.

[Rhino79]

The factory boost cars use this table aggressively for timing control, im wanting to say it starts pulling timing from 130* and up. The zl1 I did the other day was pulling 5* at 145 iat2 temp, and lowering the base iat table did nothing for the timing drop.

[Y BE AVG]

I think your issue is elsewhere related to the IAT #2 sensor calibration as it sounds like that "fixed" your problem. I dont know where/how the IAT2 sensor ties in, I believe it goes in the s/c so the ECM knows exactly what the incoming cylinder air temp is.

It is definately pulling Timing based on the IAT 2 temp sensor, there has to be something missing....

[GMPX]

took an extra IAT 2 sensor an plugged it in to the harness in free air...No timing was pulled result 672HP. left it that was to finish dialing in the car. 769 hp right now and still going
That was a good test, nice idea. I'll have to dig a little deeper on IAT sensor #2.

[wesam]

Any update about this IAT2 tables ?
I have the same problem in almost all heavily modified ZL1s CTS-Vs ZR1s
I hoop if this table will be supported ASAP

[wesam]

Any body have CAX file to show this table ?
Thanks in advance

[wesam]

That was a good test, nice idea. I'll have to dig a little deeper on IAT sensor #2.

Ross any update about this problem i faced this problem in almost all E67 cars
We need IAT2 table to be added to all OS

[GMPX]

Hi Wesam, I'm still not sure what we are looking for though, there doesn't appear to be any IAT2 specific spark table. Can you confirm the timing is definitely being pulled on your tune based on IAT2 temps?
The only table that makes sense is B5147 (IAT2 Spark Table) but that seems to have disappeared in OS's later than 2008 or so, the one that only kicked in above 120 DegC manifold temps. Can you confirm your IAT2 sensor is reading that high when the power is being pulled?

[Taz]

Have any of you gentlemen tried setting the IAT Spark table (B5107) to all zeros, and then logged data looking for any unexplained variance in spark advance ?