I’m a member of several large WRX/STI sites/forums and while I lurk on every one but IWSTI, I read a lot between them all (and sometimes subscribe to those that attract my attention).
I’ve noticed a trend with Cobb AP usage. With version 3 out now, people are using the AP as a gauge (or a set of gauges). That’s OK, but I don’t think the unit was designed to replace an actual boost gauge and I’m pretty sure the mechanical gauges will always be more accurate. I guess it’s OK to use the AP in that capacity, but it can be dangerous if you’re depending on it in that capacity. It’s one thing to use it while knowing that it may not be 100% accurate…it’s another to think or assume it’s the better tool, because it isn’t.
As well, I’m also noticing a trend where people will use the AP as gauges and monitor real-time in lieu of logging events via the datalog feature. This thread in particular highlights this problem. That is definitely dangerous and here’s why: Monitoring gauges real-time isn’t really real-time if you’re not watching them (you’re not going to be able to watch them and drive at the same time…you might think you can, but you can’t). Now, under each virtual gauge, there are areas that monitor the lowest and highest measurement of that particular gauge. Let’s say you’re trying to watch the Fine Knock Learn (FKL) gauge while driving. You eventually look at the AP and see that while you weren’t looking at the gauges, the AP logged an FKL event. The counter under the gauge shows the value of, for example, 1.35. The thing is, you don’t know if it counted that once, or many times while you weren’t looking at the gauge. Also, this also tends to create a false sense of security because you’re thinking, “oh, there was only one event” when there could’ve been 20 while you weren’t looking. One measurement showing within the peak value field does not mean there’s nothing to worry about. That one measurement could be happening more than once. Very rarely do I actually see an FKL event showing within the AP gauge as it occurs (that’s only happened twice). Now, if you’re datalogging as well as live-monitoring, that’s a different story. The analogy that I used in a post at IWSTI is that live-monitoring is akin to reading Cliff Notes, while reading datalogs is akin to reading the actual book and not a summarization of the book. Based on what I’ve been reading in the forums, people are using the AP’s live monitoring as the only method of monitoring. I saw at least one guy today state that he has 70psi in cylinder #4 but when someone asked him to post logs awhile back, he didn’t have any, yet he stated that he saw knock events…it is assumed that he saw those knock events on his AP. He never did post the logs but then posted he had a bad cylinder/piston/ringland.
Subaru owners will need to be extra diligent in following their cars’ maintenance schedules, datalogging (especially after filling up the tank with new gas), not beating up on the car when the engine is cold, ensuring the oil has the proper level, ensuring the oil is clean, ensuring the engine isn’t being lugged in a high gear (no flooring the engine in high gear or on inclines)…following those instructions can lessen engine damage, but logging is key, in my opinion.