"... is the ultimate goal to run the lowest egts?"

of course it depends on your specific objective. if it is MPG, perhaps you'd be tuning for higher egts. if it is high performance the goal would be to tune for the egt associated w optimum reliable power.

during my 22 year SCCA Nat road racing career i raced piston engines for 16 seasons and rotaries for my last 6 seasons.

i built many of my piston engines which were full race twin weber dcoe carbed overhead cam 4s. 200 flywheel hp at 10,000. optimum power settings were attained and the egt was read at that point. opt egt 1.5 inches from the exhaust port was 1322 degrees.

tuning at the track consisted of observing the egt in top gear at the end of the longest straight and rejetting the carbs to get 1322.

my rotaries, dry sump 12As, big bridgeports were tuned exactly in the same manner using 1750 degrees.

as you can see, apples to apples, rotaries make 400 plus degrees more egts.

since we run turbos and make a huge additional hp and heat than my NA race motors we need to run cooler.

we all use our experience and additional guidence and i listen especially to Jose LeDuc who suggests 1630 as optimal egt on gas. everybody has their own number but that's probably the right neighborhood. measured just after the exhaust port.

i measure each rotor digitally and log it. i just don't think you can get alot out of watching an analog gauge. i run different settings for each rotor to achieve matching egts.

since i log egts i am able to easily determine reaction time. i run the Teamrip.com thermocouples. there is no lag whatsoever as measured from my datalogit log. the thermocouples are $45 each. Jeff Feltman (Jeff48) designed a circuitboard using the Analog Devices AD595 chip... pretty simple stuff. and inexpensive.

i have LOGGED over 3500 miles this summer and conclude, as i expected, that knowing your egts is essential. you can have acceptable afrs and unacceptable egts. out of range egts blow engines.

egts are a key ( not necessarily THE key) to making power as they will tell you where your ignition needs to be. firing at the moment of maximum dynamic mechanical advantage levers the rotors torque production. you won't find it looking at your air fuel.

i am just about ready to start exploring transition areas of the map between zero boost and full boost to see if i can/should bring up the egts to produce more torque. any thoughts of course welcome.

howard coleman

 

That was fantastic.

Do you have any thoughts on egts at different rpms?
I know most people take away timing at max torque for safty...but, thats gotta mess with the temps too.

Is there a sweet spot for temps or is it all mostly liner ie.,
lean afr is hot and overly rich afr is cool/too much advance is hot and to little is cool?

 

Is there a sweet spot for temps or is it all mostly liner ie.,
lean afr is hot and overly rich afr is cool/too much advance is hot and to little is cool?[/QUOTE]

True, until you burn the gas in your exhaust manifold and temps will go back up...