Hi

I dont know how performance related/enhancing this is. I guess it is since it about detonation and preventing it, it could be. I have never heard pinging, is it loud and

like exhaust valves closing? or lighter, and quieter?

Right now I have heard a noise like exhaust valves closing/leaking exhaust gaskets. I have only heard this noise on 2 of the roads that I have driven on, which makes

me think it is more detonation than exhaust gaskets. Acceleration and power is good also.

The sound is like exhaust valves closing and, a metallic rap rap rap, but only under boost but not always under boost. I tried this morning, around 50 degree F

weather if it matters, and I could only hear it twice. The first time it was in 2nd gear and hear it almost the whole time in boost then.

It was not evident in 2nd gear, but then was in 3rd briefly and not in 4th gear. Course once I hit 4th gear the outside noise makes it hard to detect.

I am really timid to drive the 242T now because of that noise.

So is it possible to have detonation on a B21FT that is bored over .030, stock turbo, non-intercooled, 6 PSI?

In my mind if the timing is advanced far enough you could get detonation under NA format if fuel got thin enough. So detonation with turbo is even more possible.

To make sure this is the problem I am tempted to buy a good Air/Fuel ratio gauge soon. I had planned on getting one soon anyways. Recommendations for that?

I posted on this list mainly because of all the turbo and tuning knowledge.

I apologize if this is considered a non-performance post.

thanks

take care

Luke

82 242T 162K miles