Heres a thought on passing emission test

[Power Hungry]

While I was still at Edge, we had a guy bring in a truck that had a Vortech blower on it. Nothing fancy, just a simple 8 PSI setup. They were provided a programmer (I won't mention which) that was supposedly set up for the blower and the injectors. All we were supposed to do was dyno the truck just to see what sort of numbers it ran. Not a big deal, right?

WRONG!

We got 3 runs out of the truck. After the third run, the truck developed a miss and started running VERY badly. We shut it down, let it cool and then pulled the number 1 plug. The ground electrode was gone! Not singed... not pitted... but GONE! At that point, we put the plug back in, rolled the truck out the door, and handed the guy his dyno graphs. Incidentally, the truck made about 40 HP over an average stock truck.

The guy tows the truck to the dealer and they tear into it. 5 of the 8 plugs are demolished with the remaining 3 still suffering heavy damage. That was the good news. The bad news was that the number 3 cylinder had a hole the size of a pencil in it. Nothing else to say but...

Now you may be wondering what the specific problem was. Was it too lean? No. AFR on the run was actually rich at about 10.8-11.2 during the run. The actual problem was two-fold.

1) The timing curve was too aggressive for the fuel being run. Utah Premium gas is 89 Octane and the tunes were set up for 93 or better. Running boost at altitude isn't like running naturally aspirated. You can get away with 93 tuning on 89 octane fuel when naturally aspirated. You can't under boost.

2) The friggin' idiots that did the tuning TURNED OFF THE KNOCK SENSORS! Why?? Because supercharged vehicles tend to create a sonic vibration that can closely resemble detonation. This erroneously trips the knock sensor and pulls back timing. While this, in and of itself wasn't the reason for the failure (an over-aggressive timing curve was), by shutting off the knock sensors they removed the only safety fuse that would have prevented a nuclear meltdown of the engine.

Unfortunately, because the exhaust system was so loud and the intake made so much whine, nobody ever heard the detonation. Normally we'd use a standalone knock sensor with visual indicator, but since I wasn't dynoing the vehicle nobody thought to use it. I didn't get called in until the whole thing went south.

Ah well. You win some... You lose some...