2008 Z06 Spark issue, was it CFCO?

[Tony @ MPH]

Still learning all this E38 and E67 stuff.

I am playing with/tuning our latest mule, a 2008 Z06. Was able to lean out fuel as expected and get that in line (it was seeing 10.9:1 and below at WOT from the factory... wow ). Spark was a different issue.

I started tweaking and pushing the spark reducing tables like IAT and ECT (welcome to sunny Florida, where your timing will be about 10 degrees below what you command it if you leave those stables stock!). That offered some improvement but in many cases this car was only seeing 10-12* at WOT. Started bumping the spark high/low tables just like we do with LS1s and saw some improvement, which seemed proportionate to the amount of timing I put in those tables but stopped getting better after a certain point.

I pulled my hair out all night combing through all the spark tables, making sure knock was tuned where I wanted it to be, but could not figure out what was going on (I had the Dec E38 cals, so I also had no spark DMA pids to do troubleshooting).

At any rate, I just found the CFCO table. Hmmmm. This is new.

If I read correctly it sounds like spark will be ramped from CFCO to spark high/low upon launch (clutch pedal in and then out) and each time the pedal is pressed (between gears) spark will ramp from my higher values in hi/low to the lower values in CFCO.

Did I read that right? Is that why I could never see more than 16* or so at WOT at the track?

I hope that's it because I've never had so many fits trying to get a vehicle's timing advanced.

If that's not it, any tips? It is clear that aa modifier of some sort that I have not found yet is tweaking my timing down from what is commanded, and whatever it is, it's not in the spark folder in EFI because I have gone through that list at least 10 times....

Thanks for any input.

Tony

[GMPX]

Tony,

CFCO is really just used to smooth things out, to stop sudden jerks as the clutch is let in and out.

If you are running EFILive v7.5 then you should be able to log quite a number of spark DMA PID's for the 2008 Z06. The DMA PID's are not actually defined in the .cal files that are posted up here, it's within the scantool itself.

Was the timing way down everywhere or just at certain RPM's over the WOT airflow range?

Cheers,
Ross

[Redline Motorsports]

Like Ross stated; I would log some of the adder pids to see where timing is going. Make sure you check the spark timing vs. EQ ratio table as well.

If you want, send me the file and I'll check it out. Sometimes its easy to space over some of the mutiplier tables.

Howard

[Tony @ MPH]

Howard, Ross --

Thanks guys. I will check into it and send you some more detail.

Howard, I really appreciate your offer, I may take you up on that. I was staring at the tables for way too long, I am sure I just skipped something simple. From what I recall the EQ vs. Spark table was all zeroes.

Regards,

Tony

[Redline Motorsports]

No problem. We have done our fair share of ZO6's in the last three years. My e-mail is howard at redline-motorsports dot net.

Howard

[jfpilla]

No problem. We have done our fair share of ZO6's in the last three years. My e-mail is howard at redline-motorsports dot net.

Howard

Howard knows his Z06 timing and is a good guy for helping. I took his advice and it helped a lot.