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 =
- AFR lower or higher then 14.7 = Less EGT
My ignition map when EGT was too high:
The marked area is my cruise cells.
I added spark to the cruise area like so:
The EGT dropped by as much as 300C/570F~ !!
Beside the ignition map update I did something else that I didn't thought is responsible for the big change in EGT - I was wrong...
As I wrote:
- AFR lower or higher then 14.7 = Less EGT, max EGT @ 14.7
I changed my afr map - that is incorporated into ve table, so every change I make in the afr table should bring the afr to the value present.
High EGT AFR Table:
Keep in mind that my wideband could be off a little... still checking.
Low EGT AFR Table:
As I wrote:
(real) 14.7 will get the highest EGT, lower or higher AFR should get lower EGT, so...
15.4 got me very high EGT, 14.7 gave very cool EGT, I think my wideband is a little off.
Could be my 15.4 is closer to real 14.7 and my 14.7 is lower then real 14.7.
I need to find a way to check that.
Anyway the AFR change made the big difference in EGT.
Change it and you will see the difference in no time.
:)
*****In the new post about mileage EGT and AFR I sort things out - please check it out.*****
