sputter after 4k

[kidtsi]

Tonight i was tuning my car, im running E85 but after around 4k the car start to sputter, but how can be that possible if my air/fuel mixture is exactly 12.3 and my timing on top of 4th gear is around 24? Everything in the log seems ok and it evens keep going without any count of knock.
I know my knock sensor is working because i increased the timing and it knocked around 1.2 to check.

Sparkplugs are ngk bpr7es gap at .27 and MSD ignition wires. I was thinking maybe ignition wires, it seems that something doesnt let me run more than 36lbs/min on an brand new HTA FP green.

EDIT: yes i check for boost leaks yesterday.

 

[Maximuscr31]

I had a bad ground and bad battery that was causing that once. I tried everything, and finally redone my ground wires and replaced the 5 year old battery and it was as good as new

 

[dsm03]

I had a bad ground and bad battery that was causing that once. I tried everything, and finally redone my ground wires and replaced the 5 year old battery and it was as good as new

That's interesting...

 

[kidtsi]

It can't be that my fuel pump is working at full potential and the sputtering wasn't there before turning the boost.

 

[jeffo]

Have you tried a FRESH set of plugs?

 

[TSiAWD666]

Whenever I've sputtered above 4k rpm it's because:
1) boost leak
2) bad plug
3) bad plug wire
4) bad MAS (I ruined it by spraying carb cleaner instead of some sort of sensor cleaner which melted the sensor element)
5) severe exhaust leak, like a loose exhaust manifold stud or blown gasket
6) Water in my spark plug wells (after splashing around during a rain storm puddles splashed up into my spark plug wells haha)
7) disconnected fuel pressure regulator boost line (so fuel pressure wasn't rising beyond base)

That's all I can think of right now.

 

[kidtsi]

it was my damn sparkplug wire touching metal when underload.