So the car was running fine with Vortech Kit at 11.5 psi for like 20.000 miles with no problem. One day, it started misfiring at 8K rpm.It goes fine all the way up to 8K but then starts misfiring and has a really hard time going up to 9K. We changed the plugs a lot of times and tried different ones too. We tried NGK BKR8, NGK R5672-8, stock PFR7G-11S but did the same thing with all of them.
We sold the SC kit and got us Inlinepro stage 2 kit with a new EMS. Still having the same issue. Installed the Vortech Kit on the new owners car with the old EMS and installed the same plugs that was on out car onto his to see what will happen. His is revving all the way up to 9K rpm with our old kit, ems, and plugs with no problem.
We did a full retune after the turbo install but still having the same issues. If the car is %100 throttle, it will hit 8K rpm, start misfiring and the rev hardly goes up. If we use let's say %60 throttle, everything is fine and we can rev up to 9K rpm.
We also changed the coils with new ones and still having the same problem. I don't think we need better coils like Okada since the car was running fine for 20.000 miles with the same setup and also the new owner of out kit is not having any issues.

Basically:
We know it is not the coils
We know it is not the plugs
We know it is not the tune

So what else can be the problem??

Update!!
We changed the crank position sensor and cam sensors today and still no luck. It is still misfiring...

 

Could be coil drivers in the ecu? Have u tried swappin it out? What ecu are u using aem?

 

we had 30-1052 with the SC
now we have EMS Series 2

had the same problem with both...

 

Problems with your ecu picking up readings from your crank pos sensor

 

will change that too and post the updates here. thanks...

 

changed the crank position sensor today and tried it but still misfiring. then we changed the cam sensors too but still no luck...

 

You said you changed the spark plugs...what did you gap them to?

 

0.028 - 0.030
they were running fine with this gap when it was SC'ed for 20.000 miles

 

anything???

 

Checked the oil?