Recently went stage 2, Cobb AP tune after bolt-ons, I ran the AP dyno and was at 290-295 hp initally. I ran my car in 4th gear until the engine shut off and all the lights came on at about 125mph (what happened?). As of recent, I've ran the AP dyno again a few times and I am targeting around 240 hp. What happened to the lost hp and how can I get em back? Thanks for your time.
So your using a stage 2 map without a downpipe? You shouldn't be using stage 2 with stock downpipe . For the loss of power I would start by checking your uppipe for leaks, cracks, or broken welds . Then check all your hoses and turbo connections. Any strange noises?