knock under light acceleration

[wtfo09r/t]

i have a 2009 charger r/t road and track and i just shortend my intake tube and im now getting st knock at 2000rpm up to 4 degrees when i start to mildly accelerate from a cruising speed .it goes away once the car has no load on the engine. i run shell 93 and im running the 91 cai tune. thanks for any help in advance.

[Mike_Levy]

Get a Catch can if you don't have one, and STOP USING SHELL GAS. Shell always knocks like crazy. The additives have no knock resistance. Use Exxon/Mobil or BP only. They have the most resistance, which Hemis need badly.

[wtfo09r/t]

Thanks a lot will do

[MikeGig]

I have the same probleme but it started about 1 week ago never happened before.

LT knk retard start from 1500 rpm to 2300rmp and varies from .5 to 2

I'm running 91 oct with the 91 oct cai tune, no catch can which is in the mail.

same fuel as usual (been tuned for 4 months now if not more)

The above brands are not available in my city (quebec, canada) there for running ESSO gas

[fordomatic69]

My Maggie never liked Esso gas that much. I run Petro-Canada 91 or Ultra 94 and rarely get any knock. The new Shell gas in Canada with Notrogen knocks worse than Esso. The Pioneer 93 is pretty good if you can get it. I have not tried the smaller brands like Ultramar, etc. in my car but I have had to put it in my Harley and it's heavily tuned. I never saw much knock so it may be okay.

Trinity Beta Tester
InTune Beta Tester
PowerVision Beta Tester (Harley-Davidson Tuner)

[alexgrind]

I have the same probleme but it started about 1 week ago never happened before.

LT knk retard start from 1500 rpm to 2300rmp and varies from .5 to 2

I'm running 91 oct with the 91 oct cai tune, no catch can which is in the mail.

same fuel as usual (been tuned for 4 months now if not more)

The above brands are not available in my city (quebec, canada) there for running ESSO gas

there is petro canada with 94 octane everywhere in quebec

[MoparMexican89]

that explains a lil. i have a knock sound with any kind of light acceleration and on my racing acceleration, ive been between shell and exxon and it goes away and comes back