Couldnt agree more, but ive seen tuner do installs without them enough to know it happens around here, usually the excuse is the owner didnt want to spend the extra for the sensor and install! Crazy.
Will be very interesting to see if it can pass a drive cycle with the bigger cams, cant think of a more deserving winner, congrats. I would go the 270's only because i want to know if you can get it past the drive cycle so i can
Im not sure if you can do anything about the barometric pressure compensation, as that should be built into the firmware of the ecu, however the IAT table makes a massive difference. From what i see a lot of tuners dont think outside the box and realise just how important having an Air temp sensor, and the correct corresponding numbers in the table.
If it is a temp and barometric pressure issue, it could be far more than 5% if none of it is corrected, however 10% still shouldnt be enough, however i have seen it happen without the use of an air temp sensor, basically in summer blowing black smaoke, and lean in winter.
Yes the stock dump pipes` should fit, you will need to make a 2 into 1 intake pipe for the afm though. curooius why though when a bolt on turbo would probably end up cheaper with more power?