Here’s a way to get all the power out of a jb4 with a custom map6. Now you have to keep in mind not every car is the same. So doing test runs and logging your car is very important.
Step 1: log map5 and let the car do the shifting
Step 2: figure out at what RPM the boost drops and mark it
Step 3: log again with your shift points (before boost drop) to make sure your car doesn’t go into overboost
Step 4: set map6 to 7 all around and work your way up
IG: Stinger_gt21
My results are also in the video