Im running a stock MCS here in salt covered chicago...

Whenever i wot to approx 5k+ rpm, Im feeling something
like the motor pulling timing (retarding) to prevent knock.

Is your MSC doing this as well? DSC is off.

Im using Shell premium gas.

 

so all your's cars are running without this retard timing feeling?

hummm... I think the gas is to blame, but
i haven't increased boost so wasn't sure wat it is. The car
runs smooth otherwise.

 

I may not be qualified to recognize this. Please attempt to describe it and I will look. I did fill up at a Shell station and I do feel the car is less happy than it was with the Sunoco 94 I usualy get. Wheel spin is such a issue lately I haven't done too many wot blast to 5,000 lately. I am in Michigan so or fuel should be the same.

 

It feels as almost the DSC kicks in while your gas pedal is floored
even though DSC is turned off.

Its like the rev plateau's a little past 5K rpm while your pedal is
to the floor.

 

It sounds like what I feel. The way it apeared to me though is I noticed more of sudden kick in the pants at 6,000 rpm. Now I did recently add the pulley and gave the credit or blame to it. Is it possible that at 6,000, the ECU no longer needs to do this timing retard because the AFR is richened by the ECU normally ?

This flatness at times seemed noticable in the heat of summer as well. I never really heard anything (I guess you wouldn't) to indicate this was what was happening.
Somebody here I believe was trying to capture data from the sensors in attempt to solve the mystery of the yo-yo. I guess I am suprised that this wasn't seen. I no nothing about what he using for data logging or if the knock sensors were even one of the sensors he was looking at.
I do know my car was happiest on 94 octane throughout the summer, and there was a brief period in the late fall when temps were low and the fuel good, that my car very happy indeed.
So my guess is right on.