found this in mitsu's technical papers. It explains the design changes in the coolent passages in the head on the 9, and to me means the 9 is slightly more knock resistant than the 8. could make for interesting reading for those out there sorting out ecu flashes on the 9 like dynoflash
Study of Engine Cooling Technologies for Knock Suppression in Spark Ignition Engines
sorry if a repost

correction/clarification...the paper is not specific to the evo however the info from that study was implimented on the evo 9

 

Nice find. Interesting info on the cylinder head changes for the Evo9.

 

This is very important information

i have been seeing that the Evo IX is far more knock supressant than evo VIII's

I assumed the most of this was due to the reduced back pressure as a result of a more efficient turbo design

This is crucial data here and very interesting indeed

I will be digesting this further

I love mitsubishi !

 

Very interesting! Makes me wonder if it would be worth it down the road for VIII owners, when extensive head work comes into play...

 

a quick glance, looks like you could modify an 8 head by carving a channel between the cylinders

 

here is pic from evo 9 tech changes

 

doesnt seem like much but maybe this is why
and running a cooler t-stat could help
I should correct myself on the original post, the paper is not specific to the evo however the info from that study was implimented on the evo 9