VE, spark and EGT I think I got it...
 

Hey,

I started notice that my EGT while cruising is alarmingly high.

I could get up to 950C/1750F+, at first I thought the EGT is off (it does have a bad ground and the needle jumps around sometimes)

One drive when I was cruising @ 100kph/60mph~ I saw the EGT is very high, for every little gas pedal moment the EGT would raise even more...

It was dark, I pulled over and opened the hood, the exhaust manifold and the turbo turbine were glowing red like I never saw it !

Investigation begins...

Many reading days later, conclusions:

- Higher BTDC degree = Less EGT = Less power
- AFR lower or higher then 14.7 = less EGT

My ignition map when EGT was too high:
https://www.miataturbo.net/attachmen...1&d=1425977615

The marked area is my cruise cells.

I added spark to the cruise arae like so:
https://www.miataturbo.net/attachmen...1&d=1425977637

The EGT dropped by as much as 300C/570F~ !!
Of course the power in the area dropped too.

I'm ultra happy with my little win :)

Now I need to find the right balance between EGT and powa.

That's a fuel economy and emissions loss probably also.

What will be an acceptable EGT for cruise considering a good power/fuel economy and emissions ?

Thanks

My cruise kpas are usually around 35-50 kpa.

Sounds like you either have a heavy foot or ? ? ? Vacuum leak?