Originally Posted by Jon ERST S2

I found the 0.55 to be the best in terms of power/lag on the 2.1ZVH.

Here is my graph. Running 20psi.



Peak power is only at 5864. It does still make good power after that but does drop a little. I think it would have been a little higher if I had of had one of Karl's heads. I gather from speaking to a few people that my head was infact ported and with wasted stem penny valves (not larger though) so a proper stage3 / race spec head from karl would probably put it up a little higher.