I had my buddy come down to the shop with his 2000 BMW M5. I previously owned this car and sold it to him about a year ago. Now that I had my dyno finally all setup, and software ready to go, we decided to give this M5 a try and see what it can do.
Dyno: Dyno Dynamics running at 1.0 correction off the weather station, reads 15% lower than 2 local dynojet dynos, I will include dynojet number in parenthesis for comparison to dynojet numbers. All pulls were done in 4th gear, nothing was changed or moved, car never left the dyno. Temperature stayed pretty much the same the entire day.
Engine mods on the vehicle: Underdrive pulleys, K&N drop in air filters, cat delete, supersprint x-pipe (removes resonator) midsection, custom 2.5" straight through mufflers, stage 2 clutch.
Stock: 327whp and 368wtq (Dynojet: 376whp)
Tuned: 343.7whp and 378wtq at peak (Dynojet: 395.2whp). Torque gains are more than 20wtq 4200-5000rpm.