Went to an autox test & tune day yesterday. I made 2 runs, Em (my wife) made 2 runs, and I made one more run. LOVE the new tires! (Khumo Ecsta XS) Of course, when comparing to the all-seasons I was on last year, it doesn't take much to be impressed. Anyway, on this run, the new tires let me keep my speed up very well. So well, that I ran right past redline in 2nd gear. An odd sound was followed by some power loss, and I thought I could hear the engine "chugging" as I finished the run. Parked it & let it cool down quite a bit, started it up & couldn't hear anything odd. Made one more run, and it definitely had power loss, and I could hear the chugging by the end of the run. So, we called it a day, got a refund for saturday, knowing we wouldn't be able to make it back tomorrow, and headed home. Stopped partway home for some dinner, I figured it might help whatever part was crapping out to cool down. Got back on the road after dinner, and it didn't take long for a good rod knock to become obvious. Got pretty bad by the time I got home, so the engine is done, though rebuildable sometime down the road. But, I won't be rebuilding it to put back in the car, instead I'll just move up the timeline to swap the engine out of the SL2, which has SCAT rods, hyper pistons, a ported head, and a ACT 6-puck. I'll treat it like a stock engine for a while, but "someday" I intend to do a mild turbo build on it. We'll see what happens. I can always drive the suburban til all this is done... good thing gas is still fairly cheap.