Jeep GC WK2 Tune pulling ST knock

[Dguth]

Got my Trinity yesterday and installed the 93 performance tue on my 2012 Jeep GC SRT8. I noticed today under WOT cases the ST knock would show between 2 to 4 degrees. LT stayed at zero though. Should I be concerned or adjust the fuel or anything? I have no other mods on the vehicle at this time.

[mopar-srt8]

You should data log and see where it happens. or try the 91 tune. I can get My challenger srt8 M6 to have st/kr if I step on it at low RPM. Even with the stock tune it has some st/kr and I can hear some ping. This never happened until they switched to winter blend gas.

[Mike_Levy]

All Hemis knock. Its to be expected. Add fuel in the rpm range where its knocking.

[Dguth]

Thanks guys! First time data logging, so I will try it tomorrow. I also might install the stock tune back just to see if it's happening anyway. I usually always buy the same gas from BP but I bought some from this Bullova station today on Long Island. Didn't know there was a winter blend.

[mopar-srt8]

I am sure that You have winter blend in NY. Here on the west coast all gas brands share the same pipe line from the refinery to the distributaion stations and the only difference is the additive package that is add to the truck when filled and is slosh blended while being transported.

[Mike_Levy]

We sure do have Winter blend in NY. Thats why I've exclusively been using E85, because the regular gas is garbage.

[Dguth]

Ok. I'll add some octane booster in the tank today. Anyone recommend a certain kind?

[Mike_Levy]

NOS Race Formula is the only one that will do anything. Plus the Hemi loves the nitromethane shot thats in there.

[beachking2000]

What did you have ti do to run e85 in your hemi mike?

[RT23]

Dguth,
Seems to be a common issue. This is the first Hemi I've owned, 2012 RT 5.7 M6. I've installed the stock tune too, added fuel to all tunes across the RPM range up to 10% and still have knock. I'm searching for an answer and will let you know if one is found.

[Dguth]

Thanks RT. I'm new to the Hemi engine as well. Came from an Audi S4 that I had heavily modded. So just trying to educate myself on the new verbiage in these forums and what options are available.

I loaded the 91 tune earlier and it still knock with only up to 2 degrees versus the 4 I saw on the 93. Ive loaded back in the stock tune just to see how it reacts until I can get some octane booster. Dont want to mess with the fuel ratios yet as I'm not sure what I'm doing.

I also haven't installed a catch can yet do may have a little oil in there. Looking to do that soon; only have about 7500 miles on the jeep.

[Mike_Levy]

What did you have ti do to run e85 in your hemi mike?

I don't have a Hemi anymore. I have a Flex Fuel GM now, so it takes E85 from the factory. From what I've heard, the Hemis will run E85 from the factory too, as long as you have the proper tune for it. I think just about any CMR dealer can do an E85 tune for a 5.7 Hemi. Lots of guys running it.

[beachking2000]

Good to know theres no need for pump injectors or lines.

[mopar-srt8]

Thanks RT. I'm new to the Hemi engine as well. Came from an Audi S4 that I had heavily modded. So just trying to educate myself on the new verbiage in these forums and what options are available.

I loaded the 91 tune earlier and it still knock with only up to 2 degrees versus the 4 I saw on the 93. Ive loaded back in the stock tune just to see how it reacts until I can get some octane booster. Dont want to mess with the fuel ratios yet as I'm not sure what I'm doing.

I also haven't installed a catch can yet do may have a little oil in there. Looking to do that soon; only have about 7500 miles on the jeep.

I also get 1 to 2 st/kr at redline. It spikes and then it is gone. On My datalogs it happens as the throttle is closing. I read that the info for the PIDS comes one at a time and if you have too may PIDS being monitored, there is a slight delay. I am thinking that if I make My own gage layout and monitor just st/kr and throttle position then it will be closer to real time.

[barish93]

i drove mine around with the 93 tune for the first day and it was fine. I never saw more than 3 ST knock. But on the second day it seemed to get worse. I saw it keep hitting 5 ST knock on the highway sometimes and under WOT it peaked at 8 ST knock. This seemed very high to me so i went back to the stock tune. Any suggestions on what i can do to get the ST knock down?
Also my LT knock has always stayed at zero. Not sure if that's important.