How harmful is mild detonation at part throttle?
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TECH Senior Member
Joined: Nov 2001
Posts: 7,234
Likes: 1
From: Mississauga, Ontario
How harmful is mild detonation at part throttle? When I last had my car dyno tuned almost a year ago, right after I had the Vararam installed, one of the changes I had them make was to give my car a bit more timing in the lower rpms, in order to make the throttle response a lot better for driving around town. It definitely succeeded, but ever since then I have been getting very mild pinging at lower rpms (even with 94 octane), usually it doesn't show up until the car makes the shift into overdrive, although in hotter weather it'll do it in 2nd and 3rd too. It's only there between about 1000 and 2000 rpm. At full throttle/high rpms there is no pinging at all, when I had it dyno tuned I was running 91 octane and it showed no knock retard at all in the higher rpms.
So I'm curious if this mild pinging is something that is going to reduce the life of the engine, or is it safe considering it only happens at lower rpms with light throttle? I will add that I always get my oil analyzed after each oil change, and my lead wear numbers are very good, which suggests to me that my bearings aren't taking a beating at all from the pinging. And when I changed my plugs recently they looked good too, so signs of distress like they would look if the pinging was more severe.
I drive my car everyday and drive about 18,000 miles a year, so I've put close to that amount of miles on it since the last dyno tune.
So do you guys think I should go back and get some timing taken out? I know that's the easiest solution here, but I would really hate to lose the nice low end torque boost that the extra timing gives me, and if it's not harming anything and is just an annoying sound, I'd rather leave it as is.
So I'm curious if this mild pinging is something that is going to reduce the life of the engine, or is it safe considering it only happens at lower rpms with light throttle? I will add that I always get my oil analyzed after each oil change, and my lead wear numbers are very good, which suggests to me that my bearings aren't taking a beating at all from the pinging. And when I changed my plugs recently they looked good too, so signs of distress like they would look if the pinging was more severe.
I drive my car everyday and drive about 18,000 miles a year, so I've put close to that amount of miles on it since the last dyno tune.
So do you guys think I should go back and get some timing taken out? I know that's the easiest solution here, but I would really hate to lose the nice low end torque boost that the extra timing gives me, and if it's not harming anything and is just an annoying sound, I'd rather leave it as is.
if you can hear it... then its no good... detonation / pre-ignition will cause unbalanced cylinder pressures and make your timing seem off. in term lose of gas mileage and can cause internal damage. id suggest a proper dyno tune that can take timing out when the air is hotter. etc.
