Experts, please help with KR

[98VertPDX]

Hi,

My 2007 A6 Coupe, with stock programming has more KR that I would think is reasonable (see enclosed log.) This is my second time scanning my C6 and feel that there is something wrong with it.

Can experts give me a hint what my options are in programming this KR out? I used HPTuners for my Supercharged C5 successfully, but am very new to the LS2 & the new PCM...

Thanks in advance,
Luis

[flea]

Comments from a quick view of log file

1) You are definitely getting some "real" KR. Buy a wideband O2 and dial in the fuel. You could be rich or lean in the areas you are getting KR (contributing factor).

2) Part of what you are seeing is burst KR (frame 13778 in particular). This is typical. You can dial this back some but I would still recommend getting the fuel straightened out first.

3) IAT was at or above 120 for most of the log. Your stock calibration is pulling timing with these kind of IAT's.

4) You are running 91 octane or above?

[98VertPDX]

Flea,

Thanks for the info. I am running 93 octane gas...I dyno'ed the vehicle a couple of weeks back and the numbers were very low... If I find the graph I will post...

Thanks,
Luis

[flea]

The dyno will provide a good starting point for tuning. Was the car also street tuned at the same time?

Post your current file. The more information we have to work with the better. Has anyone adjusted the timing tables, etc.? With the stock calibration all the LS2's I've seen have a little KR. Yours seems to be more extreme than others. Nothing that can't be corrected though.

[98VertPDX]

Hi Flea,

I can post the file, but the callibration is exactly the same as the stock one (2007 A6) on the tuner repository (that was the first thing I compared..)

No tuning has been done on the car at all, just trying to understand why it would have so much KR with the stock tunning.

Thanks for your help, greatly appreciated.

Luis

[Street Legal]

Hi Flea,

I can post the file, but the callibration is exactly the same as the stock one (2007 A6) on the tuner repository (that was the first thing I compared..)

No tuning has been done on the car at all, just trying to understand why it would have so much KR with the stock tunning.

Thanks for your help, greatly appreciated.

Luis

Look at the IAT SPARK TABLE u will see from 113* and above..the pcm will pull timing about 8 to 12*..and you are running at 127* IAT temp thats why it's retarding the timing all the time..there is another thing am not sure about some ppl say the knock sensors in LS2 and LS7 are sensitive and u need to play with initial level and make sure u dont have an actual knock..some one correct me if am wrong

[98VertPDX]

Thanks Street Legal, I will check those out and rescan before trying anything ;-)
Best regards,
Luis

[flea]

If you are interested ......... let me know and I can help you resolve the KR issues. I've been playing with LS2 GOATs and C6's for about a year now. Definitely a different animal than Gen III's.

[Redline MS]

Look at the IAT SPARK TABLE u will see from 113* and above..the pcm will pull timing about 8 to 12*..and you are running at 127* IAT temp thats why it's retarding the timing all the time..there is another thing am not sure about some ppl say the knock sensors in LS2 and LS7 are sensitive and u need to play with initial level and make sure u dont have an actual knock..some one correct me if am wrong

Timing taken out by "trim" type tables is not KR. It will just add or subtract off the base timing tables. The KR is from the knock sensors either picking up real knock or false knock or it from the MAF reporting burst knock.

You could try some octane booster to see if it clears it up. This will at least indicate its detonation.

[EC_Tune]

Every LS2s I have tuned has had real KR. GM apparently went a bit aggressive with them. Make sure you log KR as well as Total KR to see the difference between them. You can have BKR that shows up in the Total KR but no KR indicated.

Burst KR is always a factor as well. You "can" disable the Burst KR (zero the amount of retard it can pull) as a diagnostic and to see if no BKR will induce real KR.

[98VertPDX]

ECT Tune,

Thanks, will keep logging too :-)

regards,
Luis