A compression change from 8.8 to 8.5 will effect the timing in the boosted part of the ign map ?

 

No. Ignition timing is measured in degrees before/after TDC. Reducing the compression does not affect that, since TDC is always the point where the piston is highest in the bore on the compression stroke. An 8.8:1 engine and a 7:1 engine both have 10*BTDC at the exact same place...10* before top dead center.

Now, if you were asking whether or not the engine could take more timing if you dropped the compression, then the answer is yes. By reducing compression, you reduce cylinder pressures (more or less), which helps reduce detonation. If the 8.8:1 engine was fine at 10* BTDC, but knocked at 11*, the 8.5:1 might be fine with 12* BTDC, and knock at 13*. This is purely an example, not fact. You've got to tune it to find out.

 

Thanks, TBH i still dont agree with the spark firing ATDC. If you see any standalone ecu's timing map for example Link G4 , you wont find timing in -ve numbers its just less or more. This is whats causing confusion.

 

That's the way mitsubishi did it, what can I say . If it were incorrect, I'm sure Tephra, or any of the other folks out there who made this reflash tuning possible, would have noticed.

Factory ecu code is usually very different than standalone mapping, so it's an apples-to-hamburgers kind of comparison.

 

Mitsu engineers sure have done things in a unique way. I love the ecu flash .

off topic.
I am getting my 1.3u flash cable today from a friend. What things i need to check in order to see if the cable is working properly or not ?

 

You need to log Baro compensated load to know what load the spark routine is accessing.
Then take note of what the air temp is doing to get the final trimmed result.

 

Air temp
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618
106.618

Baro
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5
98.5

 

??

 

I cant get to paste the full log here. Cant attach a CSV file also :S do i have make it a winzip file first?

 

Change the extension to .txt for example and we'll change it back to .csv before we open it.

 

Just a small log using mitsulogger.
JDM evo 8