During a road test the exhaust pipe came off at WOT at about 65mph in 4th gear. I had set the boost down to 12lbs to run on 87 octane. Without the restrictive exhaust it instantly hit 24lbs. It slammed me back in the seat and a second later the engine revved way up, I thought it had smoked the tires. Then I smelled the clutch, it ran though the clutch at 70+mph. The result of the overboost and detonation was 3 cracked pistons. $149 to my door for a full set of pistons, pins, and rings and it was running again. Hey, I got 5 spare pistons to play with now. Dave