NefMoto

need a little guidance on what has changed, causing my car to be so much slower...

B5 S4 RS6/K24's....25-26 psi tuned...i have a log from several months ago with a 3.8 fats - 91 octane...same car..nothing has changed...now running mid to high 4's fats....whats causing my timing pull....can you guys see something in my logs i dont??

bad gas?

I thought that too... I recently changed gas stations and put 3 gallons of 100 octane in too...

I'm in for bad gas as well.

I mean it's a definite possibility... Car has been backfiring more than usual.... Any objections to a little octane Booster in the tank??

I think that would be inconclusive. Drain/drive the tank near empty, and fill it again at another station. Compare fuel trims yet?

My car started to knock and backfire more when crankcase ventilation was clogged. Pulled lot of oil up and through intake. Oil in intake also lowers octane rating. That was with a Volvo though. I

Lol at your quote at the bottom....

Are you referring to block.32 in vcds?? Yes and lately they have been a little wacky....

I have all new spider hose, that doesn't mean oil isn't getting everywhere...I have foam carbon clean spray... Be meaning to do that for a while...

In the meantime I'll get through this tank as quickly as possible and try another station...

Does this mean everything else in my logs I attached is looking good or normal??

Looks like you're EGT sensors picked up some heat in the second log around 6600 rpm. I would be careful. You are 10-15 degrees below where you should be for ignition timing and that's creating some heat.

ok, so I ran a few gallons of 100 octane on close to an empty tank....ran a 3.7 fats and my CF's were back under control.  ive also done some small amount of research and found out I do get winter blend fuel where I live. Ive heard and read that what they do to the fuel causing it to evaporate more easily also has a negative effect on octane...which could possibly account for my problem. My question is, what are my options......take away some timing?? Add octane booster to every tank until summer time? methanol injection??

I have yet to actually write/tweak my own file and successfully flash it.....would the best step be to figure that out and take away timing? I appreciate all input.

Might be a good idea to also log your long term knock control adaptation variables.

Which variables are these?

Read this in it's entirety.

https://s4wiki.com/wiki/Tuning

Thanks, found it in footnote 37. http://www.nefariousmotorsports.com/forum/index.php/topic,444.msg3640.html#msg3640

The variable to log is wkra.

wkra_0 and wkra_159 ......both of these, or the individual logs for each cylinders

wkraa_0 through 5

curious as to which is the better to log??

thanks again for the help