i was wondering if there are any dyno numbers floating around out there of a before / after ported cylinder head w/ +1 mm valves...?

any decently modified evo engine will suffice, but for the sake of argument, 30 psi, 35r, 110oct, 2.0L engine + all basic upgrades + ems.....

i see buschur, ams, cosworth & jam offer cylinder head upgrades, but there arent any ~ power gains associated with any type of evo 8/9 engine, from mild to wild on thier websites....

TIA

 

yea,ive got the same question .

 

Is it not done to help spool up really,,
I think upto a gt30 there is not much to gain

 

any info?