KNK LT Retard

[zteevee]

Hello everyone,

I'm new to the Predator. I'm running an '07 r/t Charger with an K&N cai, and the 91 cai perf tune. I've attached the log file from an wot run. From what I've read so far I seem to have too much KNK LT Retard. Am I correct in this? If so, how likely is bad fuel to be the culprit, or do I need to make some adjustments? Thanks.

[DGatzby1]

Wow, what kind of gas is that? If your vehicle is functioning correctly and you are not picking up noises other than real knocking that gas is most certainly BAD! Where are you in the country maybe someone can give you a suggestion on another gas? That stuff is making way too much ST knock and knocking all over the RPM ranges. Good for you for using the 91 octane program before jumping right into the 93. I would try some other gas before starting to adjust the vehicle because the 91 octane program is more tolerant than that to good premium gas.

[zteevee]

I appreciate the reply. It's Chevron 91 octane. I'm down in Austin, TX. There's a Mobil station not too far from me, I'll give that a try on next fill. Sometimes I also get some hesitation when I floor it, kinda like the car has to think about it for a sec. I'm wondering if there could be some relation.

[zteevee]

Here's a datalog from a run this afternoon after filling with Mobil 93 octane (91 not available). Knock looks to be down a little. I'm thinking that I might want to let the whole tank run through then log another wot run. Any other suggestions? Thanks.

[cleary524]

might want to invest $125 bucks in a catch can

[zteevee]

might want to invest $125 bucks in a catch can

Yeah, thats coming in about a week or so. I'm hoping that changing gas and installing a catch can will take care of the knock.

[cleary524]

I never had a change to log prior to a catch can, but I can tell you that with one I have zero knock today. It does catch the oil in the PCV return. Cleaner air = smoother power! Good Luck

[concoursd]

if you install a catch can, dont forget to clean the oil puddle in the manifold. Oil can build up pretty quickly in those cars. A puddle has been known to accumulate in the first 4,000 miles for some owners.

The puddle will continue to cause knock even after installing the catch can until is removed.

[duster360]

Here's a datalog from a run this afternoon after filling with Mobil 93 octane (91 not available). Knock looks to be down a little. I'm thinking that I might want to let the whole tank run through then log another wot run. Any other suggestions? Thanks.

Last log is not much better. ST and LT are both pretty high.
To speed things up considerably, you can "Erase" LT knock imediately simply by disconnecting the battery for a few minutes. What ever knock remains will be just seen as ST.

[broadfca]

How do you clean the oil puddle in the intake manifold.... And, when can I order a Diablo Catch Can?
2009 SRT8 Challenger

[Quick]

You have to remove your manifold (and the fuel rails with it). Not a small job.
I don't think you really have to. It just takes a little wile for what might already be there to get drawn in and burned or sort of dry up. How long I don't know and would depend on how much you got in there. maybe a 1000 miles or less?

[Lymzilla]

If you encounter 'bad' gas again you can always add in some 'ocatane booster'. It's the short-term cure for a tank of gas that turns out to be 'bad' (causing LT knock). This will get you through until you can fill up with some 'good' gas.