Ok, I'm new to the 1.8t so this may be nothing. First I have a 97 1.8tq w/APR chip. I recently installed a boost guage and learned several things. In first and second gear rmps around 2K-4K boost is 15 lbs. From 4K-6K rpms boost tails off to about 10 lbs or less as the rpms rise. Does this have to do with the torque curve? Or should I have full boost up till the red line or whenever I let off the gas?

At 3500 rmps on the highway you could be anywhere from -20 to 15 depending on whether you are under hard acceleration or just cruising.

Most chips back off the boost at higher RPMs to avoid overspinning the turbo, and to keep the turbo somewhat in it's (in)efficiency range.

boost on a turbo'd car comes only as a result of the load put on the motor not rpm dependant. The ECU / chip, on the otherhand, will artificially limit or control the ammount of boost at a particular rpm according to the desire of the chip tuner by actuating the waste gate. Now shake (and/or kiss or what ever guys do) and make up.

Jeff Davison