mnxtrik8r
06-20-2010, 09:16 PM
Detonation update
Sorry this update is so late in coming. In the past I was chasing a part throttle detonation that drove me up a tree trouble shooting. The culprit appears to be the oxygenating agent in the fuel. I had been using a non oxygenated, ethanol free fuel with an octane rating of 94. This detonation occured with the 91 tune. After talking with a tuner in the metro area, he spoke of a Cobra experiencing the same exact problem, using the same fuel as I. It was suggested to put 91 octane pump fuel (with ethanol & oxygenating compounds). Reluctantly I tried this and it appears to have eliminated the problem. The lesson learned to me was not to rely on the octane rating solely. There is more to fuel than just an octane rating. This non oxygenated works well on small engines as it allows a longer storage time and retains it's potency for a longer time. Unfortunately I think the light detonation took its toll as it appears there is blow by residue pushed back through the the inlet side of the pcv system LH rear. I have not had the time to work on figuring that out as my promotion at the Department has consumed any free time that I had. Not sure if I cracked a ring or what. I am going to drive it and see what materializes. I am not crazy about using a catch can on this particular application as I was told previously that is wasn't necessary. I may change the pcv to a Cobra one, Any thoughts? At any rate, thanks for all your input in the past, I really do appreciate it.
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Sorry this update is so late in coming. In the past I was chasing a part throttle detonation that drove me up a tree trouble shooting. The culprit appears to be the oxygenating agent in the fuel. I had been using a non oxygenated, ethanol free fuel with an octane rating of 94. This detonation occured with the 91 tune. After talking with a tuner in the metro area, he spoke of a Cobra experiencing the same exact problem, using the same fuel as I. It was suggested to put 91 octane pump fuel (with ethanol & oxygenating compounds). Reluctantly I tried this and it appears to have eliminated the problem. The lesson learned to me was not to rely on the octane rating solely. There is more to fuel than just an octane rating. This non oxygenated works well on small engines as it allows a longer storage time and retains it's potency for a longer time. Unfortunately I think the light detonation took its toll as it appears there is blow by residue pushed back through the the inlet side of the pcv system LH rear. I have not had the time to work on figuring that out as my promotion at the Department has consumed any free time that I had. Not sure if I cracked a ring or what. I am going to drive it and see what materializes. I am not crazy about using a catch can on this particular application as I was told previously that is wasn't necessary. I may change the pcv to a Cobra one, Any thoughts? At any rate, thanks for all your input in the past, I really do appreciate it.
http://www.motorcitymarauders.com/forums/images/misc/progress.gif