Originally Posted by
Tadias48
Alright so I'm stumped. i have a 2014 cts v sport with the lf3. I'm boosting it around 18-16 psi and I have a slight misfire at wot. I have swapped plugs with the ngk 6510 ltr7ix and gapped to .030 afr are around 12.6-12.4 and on the dyno the misfire is horrible. injector pulsewidth sees around 5 and then tapers down to 4.4 as the injectors pulsewidth drops the misfire calms down and goes away. so i take it out on the street and the misfire isn't as noticeable but its still there. i have already looked at the timing tables and ended up using the one ddtech posted. kr is down to a minimum to which I assume is false knock since I have had timing lower than this and would still show up as kr. I've tried richening up to 11.8 and misfire is still there. I swapped plugs twice already and the previous set I replaced two weeks ago 3 had cracks in the porcelain. Which makes me think the misfires are overheating the plug and cracking the porcelain.
i have attached the stock tune, and the current tune on the dyno and on the street. only difference from 18 psi2 to street is i increased fuel pressure to 3100 and I lowered the knock airmass to stock at lower rpms to try and minimize boost below 3k