> Running the 9.7 - 1 rotors in a normally aspirated engine, I can't get

the

 > engine to detonate at any combination of  throttle setting and mixture.
 > Other significant conditions which might affect the results are ignition
 > timing of 20 - 23 BTDC (both plugs, I simply disagree with those who say
 > that a 15 degree retard on the trailing plug is better), 87 octane
unleaded
 > fuel, and a worst case air temperature of 37 F. (colder is worse for
 > detonation, at least thats the way it works in my car).
 >
 >

Of course you are right tracy, the detonation I was talking about was in an
engine bosted up to over 500 hp.  I may also have been mistaken and it may
have been pre-ignition that distroyed the engine.  The guy seemed pretty sure
it was ultimately due to his injectors not keeping up with his turbo...

As different of a case that may have been, detonation is still a concern for
those of us who are turbocharging because it is untested.  BTW, how do you
know you cant get it to detonate?  Do you have some sort of knock sensor
built into the EC2?  That would be great.

Cold air being worse for detonation seems a little backward to me.  Are you
talking about your RX-7?  Corky Bell talks about the need for a good
intercooler largely to prevent detonation.  Perhaps in the car the colder air
allows for a denser air charge.  If so, even a little boost will put us into
the realm of possible detonation.

Dave Leonard

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