Attack Blue filter = KR? Or old gas? LS9

Hi there, new here, totally at a loss. I don't know where else to ask.

My 2010 ZR1 is stock apart from an Attack Blue air filter I put in recently. And then winter hit a bit. 13,000~ miles or so.

The gas in the tank was 15~ gallons from January 7th, Mobil 93. I got to drive it quite a bit this winter as it was mild.

8 further gallons were put in on 2/9, and then it sat a few weeks as there was salt on the roads.

Fast forward to the beginning of this month, I am seeing 6.5 KR at WOT, and in 6th gear to pass people. I never used to see any. And a flash of 2.5 KR at half throttle or whatnot doing half hearted pulls.

So this past Sunday I drove all the gas out to the line above empty and filled up with Sunoco 94. I have not attempted anything further to see if it is fixed.

I have plugs and wires waiting to go in. All fluids were changed recently. As far as I can see it, it's either this Attack Blue filter or the old gas not being 93. I know these cars knock A LOT on 91. I never saw any on 93 this past summer!

Or is it this Attack Blue filter? The intake is not modified. The OEM filter is no longer made. The only one available now is the more restrictive version from 06-11 Z06s. 12-13 were given the ZR1 version to compensate for the extra 2 cats. I have the original air filter to the car and it is spotless.

Any insight here would be great.

So small update. The KR went down quite a bit with 94 in some situations. But even weirder, is with PTM on mode 2 it was reduced. And on PTM Mode 5 or full off it?s gone. And then I put the OEM filter back in and it?s gone regardless. Just got a flash of 1.9 letting off in 3rd at the redline. wtf????? Is it traction/stability? Torque management? Doesn?t explain why it would do 3-6 degrees of KR in 6th. You?re not breaking traction in 6th at 75-85. The KR in that situation stopped entirely too.

Log would help shed some light, but keep in mind these PD blowers really wake up with CAI's - not sure what this filter does on it's own, but you might need to correct your fueling. Theoretically shouldn't have to since you didn't change the intake tube, but who knows how the air is flowing through the tube after the filter now.

Quote:

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Originally Posted by GHuggins

Log would help shed some light, but keep in mind these PD blowers really wake up with CAI's - not sure what this filter does on it's own, but you might need to correct your fueling. Theoretically shouldn't have to since you didn't change the intake tube, but who knows how the air is flowing through the tube after the filter now.

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This filter goes in the OEM housing and seals tight. They claim 15 hp and 10 tq. I saw one back to back dyno from LHT performance years back. Only gained 5 hp at the top but nearly 30 hp and tq in the midrange. Even weirder is the AFR was richer the entire dyno pull with the filter. My car is completely stock. I don?t even know where to start with logging this car.

Too much fuel can cause knock just as easily as being too lean. Just went through this on a LS7 I'm tuning where I had inj timing too retarded causing too much raw fuel to be in the cylinder causing about a 7 degree timing pull. Just a FYI ;)