The worst detonation I ever got was when I was
in Vegas during 115 degree weather. It would detonate at 3psi. That was shortly
before the motor went so there were other problems too.
Now, with
the intercooler
and
good motor, I can get up to 10 psi on 92 octane gas without detonating. It
will run lean though if I'm not over 4k RPM. That's because of the lack of
engine management. For electronics, I have none, I have no RRFPR yet, the only
thing I have is an Rx7TT Fuel Pump.
Here's a quick list of things that cause detonation.
Timing: Try a colder range spark plug to slow the igniting of combustion gasses.
Octane Rating: Higher octane gas will burn slower so it's kind of like retarding
the timing.
Intake Temperatures: Lower intake temperatures mean less chance of detonation.
(part of the reason for my intake insulators that drop the intake temp about 20
degrees)
Intake charge purity: If you have oil in your intake, that lowers the effective
octane rating. Check your throttle body for oil, if there's much in there, then
consider a catch can.
Carbon Buildup: Carbon buildup in the engine could also contribute to
detonation. When's the last time you ran some sort of injector cleaner or carbon
buildup remover?
Back on the intake temperature, if your wastegate is bleeding, or you have an
exhaust leak before the turbo, it's possible your turbo is being pushed beyond
it's map and now producing LOTS of heat, instead of the compressed air that it
should.