Would love some help, does anyone know if this is what detonation sounds like: ?

I did some searches on threads from years ago, people described detonation sounding like marbles in a can, which is kind of what this video sounds like.

Asking because my car is currently making a very similar noise above 5k rpm. There's no power loss, and it revs nice and responsive all the way up past 7k, it's just that the noise starts after 5k and I'm worried.
In normal lower rpm driving, that noise doesn't appear. My idle and starts are also fine.

I have a completely stock '93 with the exception having a jdm downpipe and a fc thermoswitch. Spark plugs are basically new (changed last fall).

 

Not that I am an expert on FD detonation, but in most cases, detonation is more likely at lower RPM's where 2 flame fronts have time to develop and collide with each other. So I'm guessing you're hearing something other than detonation.

Also, listening to your video, the noise I hear doesn't sound like any detonation I've ever heard - I can't tell you what it is, but I think you should look for something else. Detonation is usually a "pinging" sound that occurs with every engine combustion cycle (on piston engines, every other crankshaft rotation or multiples of that if it's happening with every combustion).

 

When I had an SA22C with the carbed 12a, I advanced the dizzy to get more top end. There was one hill I would regularly drive, if on a cold morning I loaded it in 4th or 5th at lower revs it would rattle like that. Definitely sounds the same as best you can tell through phone mic/youtube compression.

 

thanks guys, going to check my plugs just in case

 

If that was a piston car, maybe. Its really hard to tell with the mic compression. I've felt it in a rotary before and it was more of a sharp *tink* or snap of the fingers, and i could feel it resonate to the throttle pedal, i don't know if that was because it was traveling through the cable or enough to just feel it in the chassis.