Heres a thought on passing emission test

[Power Hungry]

The reason it's best to use the knock sensor as an "emergency relief valve", so to speak, is that when the knock sensors detects detonation the PCM pulls out a HUGE amount of timing in one shot to protect the engine. This will have a significant impact on performance and economy. It is much better to go with a slightly less aggressive curve that doesn't cause detonation than it is to push the limits.

One other thing to consider is that some of the earlier engines DON'T have a knock sensor to compensate for sloppy timing curves. Obviously, things can go wrong quite quickly in this type of situation.

[Jackpine]

Thank you sir! Makes perfect sense.

I asked, because again, some people on f150online have suggested it's "no big deal" if the timing is overadvanced, since the PCM will just pull timing if knock is detected. Didn't seem like a good approach to me, but I couldn't say why.

- Jack

[88Racing]

I'll just throw this in for you guys to chew on also.
With the Harley tuning software you can turn off the knock sensors. You can also turn off the heat management system.
Some bike tuners will often use these in the off position when tuning a bike on a dyno for more "true" readings.
But when done they turn them back on. Sometimes they forget.

[Power Hungry]

You want to know something funny? I've seen gas tunes from prominent tuning companies that have the knock sensor offsets set to 0 degrees adjustment. Yes, that's right... ZERO! Even worse? This was on SUPERCHARGED vehicles. I guess there isn't any need to have the knock sensors functioning on a supercharged application. What do I know.

[Longshot270]

Haha wow, I remember 88Racing once asked me if I liked playing with fire. But compared to some of these guys I was messing with water pistols.

I sure hope these guys aren't letting the knock sensor control their timing.

[88Racing]

Originally Posted by Power Hungry

You want to know something funny? I've seen gas tunes from prominent tuning companies that have the knock sensor offsets set to 0 degrees adjustment. Yes, that's right... ZERO! Even worse? This was on SUPERCHARGED vehicles. I guess there isn't any need to have the knock sensors functioning on a supercharged application. What do I know.

You've always got positive air flow Bill!
You don't need a knock senser if you have that!
j/K!

[Jackpine]

Good Lord! Nothing like giving your truck to a bunch of chimpanzees to tune, eh?

It's funny, I only bought an Edge after reading a LOT of talk about it on another forum, all positive, and after noticing how you, Bill, were always jumping in and helping people with any problems. And, when I got it, you can bet I was VERY careful how I drove the truck until I was totally satisfied that nothing was amiss. I sure didn't run right out and "stand on it" right after loading a tune, and, if any of the "Custom Options" didn't feel quite right, I'd immediately return to the programmed value. (I also worked with "small" changes, one at a time).

I didn't even consider upgrading to a Gryphon until I'd seen a lot more of you on that forum and had talked to you on the phone. I only made the jump when I became convinced you knew what you were doing and felt reasonably confident you weren't going to blow up my truck.

- Jack

[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...