Originally Posted by Jeremy@Cobb
D25 cylinder head castings castings
- Added air injection
- 49.6cc combustion chamber
- Cooling passages, and most internal area of the casting is different to allow for the air injection.
can you explain what a D25 cylinder head casting is? or do you mean it actually says "D25" on the outside of the heads?
and how is the internal area different because of the air injection?
i put an 07 motor into my car and removed the air pump in the process to make room for other things. i also recently did a TGV delete and noticed the intake ports of the heads are very rough.
thread on the subject posted here: http://forums.nasioc.com/forums/show....php?t=1337066