Good morning Gents,

Interesting issue here, since the switch to E, 3/4 to WOT in 1st and 2nd throws knock anywhere from 3-8 counts.

3rd-5th are clean. I was under the impression that Ethanol was fairly knock resistant, and the timing isn't anywhere near excessive in these areas.

Getting knock from 3k-5k, 12.5-12 AFRs through this range. I don't have any logs currently. Just wondering if my knock sensitivity needs adjusting possibly.

A full 3rd gear pull will only generate a sporadic 1 count here or there every other log.

Not sure if anyone else has encountered this, my 93 map doesn't knock here with similar timing.

 

Knock Sensitivity: Most likely not, if you're getting above 5,6,7,8's consistently timing or fuel needs addressing.

i don't at all think eth is fairly knock resistant, its just harder to detect.

ultimately without looking at logs, its a number of things that are possibly giving you this. also whats specs on your setup?

 

also inb4 rightsaidfred and you have a fuel pressure issue.

 

Full exhaust
perrin intake
omni 4 bar
fic 1120
aem e85 pump
otherwise Stock

30lbs on E85

i should mention. Adding fuel, pulling timing,in these areas does nothing.

ill try to get logs tonight.

 

i would start by looking around to see if the exhaust or other piping is banging around against anything. My hunch would be on false knock. especially considering that pulling timing and adding fuel has no effect.

E85 is ~ 105 octane so yah its gonna be much more knock resistant then 91/93. Also because you are using so much more fuel relative to gasoline it helps lower combustion temps. Its pretty well known that you can tune right past MBT with E85 and not see any knock. Which would be bad and is why tuning e85 requires a different approach then tuning 91/93.

 

Probably phantom knock. What turbo? And how much timing? Whats peak load and rpm