Quote:
Originally Posted by cdrazic93
Ive seen it eurrywhurr, what exactly is EGT, what are safe values for it, what arent safe values for it, and what causes these unsafe values?
@ jamesm |
what is safe as far as EGT has a lot to do with where the sensor is mounted. with a 'normal' setup where you have the thermocouple in the exhaust manifold before the turbo, the number you'll hear thrown around most often is 1600f. this is very debatable, as like i said before it depends a lot on the position of the sensor as well as your particular hardware setup (piston and turbine blade metallurgy, for instance).
high egt's are primarily caused by lean fuel mixtures and overly retarded ignition timing. overly high egts are every bit as detrimental as knock. they will literally melt a hole in a piston.
in this particular case it's of concern because in order to be running 20+psi on a 12.5:1 compression engine you have to run very low timing to keep knock at bay, even with direct injection. the fa20 is a fantastic engine, but it's still bound by the laws of the car gods. it's quite simple to continually add boost and make power by retarding timing (or fattening up the afr, to a point) to stay out of knock correction, it's just not safe. great for a single glory run on the dyno, not so great for beating on it in the real world out on the street or at the track.