Silly question, but what does pinging actually sound like?

I've got the blower in the car at the moment, and it roughly tuned for now.

When I give it full throttle and it gets up to about 4500rpm it makes an odd noise that can best be described as what I would expect it to sound like when a bit of debris gets blown through a muffler; that light, highish pitched noise thats almost like a small bit of material hitting a tinny, wire mesh. It doesn't happen heaps, just a little bit.

There is a s**t load of fuel in the motor at that point, the AFRs are running right down into the 10s.


By the way, do you have any idea how hard it is to describe a sound like that with words!!

imo by what you describe it sounds like its pinging,
a dyno tune is the best solution, what spark plugs are you running? you could try a colder plug to help stop pinging..

Use better fuel ( 98 RON) or the timing might need a bit of retard at that point.

Swing by my work one day and i'll have a listen.

Detonation and preignition have two very distinct and different sounds.

Cool , thanks for that guys.

Tickford_6: I am off work next week, so I was going to pop in and see you about the diff gears as well. I'll drop over Monday or Tuesday.


The plugs in the car are one range cooler than standard plugs, regapped to 0.8mm
I've only been running 98ron fuel in the car since a few tanks before the blower. Having said that, the fuel has been sitting a bit as I haven't been driving much lately.

Also, I've still got stock timing on it at the moment, I haven't played with it on the J3 chip as I don't really know what I am doing when it comes to timing.

i think you need to remove a few deg of timing...

when I used to carby stuff, we had a few blow small blocks in hot rods, Used to use the MSD 'Boost timing master' it let us retard timing based on boost pressure, the starting point was set the base at 14deg run 20deg of mechanical advance (total timing with out boost wil be 34deg)
then pull out 3deg per 1PSI of boost, That was enough to at least run the engine and drive the rod.

from there we would add timing as needed.

If the detonation is from timing, doing that with the J3 would at least make it safe. The yo just need to find someone in towsville willing to tune the J3