05-01-2011, 12:43 PM
Join Date: Jan 2010
Location: Atlanta GA
Total Cats: 0
First Experience with Det, bad gas or bad spark
Yesterday I had my first real experience with detonation. Ambient temp was around 85 and I had just filled up the day before so this was the first time I ran the car in 75+ weather on this gas. At first I didn't even hear it but the knocksense flashed twice. I boosted to about 6lbs a second time and definitely heard it.
I'm running the following spark map except that I've reduced spark in anything over 100kpa by 2 degrees:
When I got home I reduced everything in 100+ kpa by another 3 degrees and went for a spin; everything seemed fine (although by that point ambient had dropped another 10 degrees).
The reason I think that it's just a bad tank of gas is that I've been running this map for a while and we've certainly had hotter days than yesterday down here. Not to mention the relative humidity was quite low yesterday. Last week I was boosting with no problems at 90 degrees ambient and 75% humidity.
Is this something that happens often? Should I tune for lower octane just in case?
I pulled my plugs today and no signs of det, in fact they look exactly the same as they did back in February (I took pictures). Though I know that doesn't mean anything concrete it's certainly not what I expected.
Last edited by D.dutton9512; 05-01-2011 at 01:36 PM.