We installed full exhaust on the car. We went with 1-7/8" BBK full length headers and 3" race Magnaflow X pipe and catback. We did a pull a few days ago with about the same hot temps and high humidity. It just finished raining. It looks like it picked up between 25 and 30 rwhp all the way through the run. It made the same boost as before. Here's a look at the graph. I forgot to look at the torque.