tunersteve
10-20-2009, 03:21 PM
Since I've been seeing a lot of PT knock lately, I decided it would be time to do a little test. I typically drive the same route to/from work and school 3-4 times a week, so that wasn't an issue. Since most of the 22 mi. drive is highway, I usually put the cruise on at 78 mph.
So, my results after the first trip was exactly as I expected. The KR on my DH spiked up to 7.5+ for a period of approx. 10 secs. This happened both to and from. Instead of pressing 'cancel' to pull throttle, I decided not to do anything. The KR eventually subsided and came back several more times for shorter durations. The next day, same setup, different results. This time, the KR spike was lower and not as long. Again, similar results on the drive home. Temps were consistent throughout the duration of this test.
Now, each subsequent trip along my path has produced favorable results. Today, on my trip, no KR came up at all. My thought is that the car was able to learn around the KR (which no fuel was pulled, there was no hesitation). Each time as the car was driven it was able to make the adjustments with the throttle still partially engaged, which helped to force the ECU to adapt. I have now put about 400 miles on the car since the ECU was reset (following my turbo replacement), and seen these results. YRMV.
Note: I am not responsible if you choose to try this and your motor blows. This was merely a test on my vehicle.
So, my results after the first trip was exactly as I expected. The KR on my DH spiked up to 7.5+ for a period of approx. 10 secs. This happened both to and from. Instead of pressing 'cancel' to pull throttle, I decided not to do anything. The KR eventually subsided and came back several more times for shorter durations. The next day, same setup, different results. This time, the KR spike was lower and not as long. Again, similar results on the drive home. Temps were consistent throughout the duration of this test.
Now, each subsequent trip along my path has produced favorable results. Today, on my trip, no KR came up at all. My thought is that the car was able to learn around the KR (which no fuel was pulled, there was no hesitation). Each time as the car was driven it was able to make the adjustments with the throttle still partially engaged, which helped to force the ECU to adapt. I have now put about 400 miles on the car since the ECU was reset (following my turbo replacement), and seen these results. YRMV.
Note: I am not responsible if you choose to try this and your motor blows. This was merely a test on my vehicle.