Quote Originally Posted by pdt View Post
Yes the triple I have is restricted as far as doing anything with the exhaust housing for sure.
its not like the older type that could come off and be given a different exhaust manifold.

the 120 psi really does surprise me, if mine was 120 I would dump it....I have 148..149 ..148.
somewhere on here iwas told I need to get to atleast 165 psi and that maybe getting rid of the small reliefs could give me 10psi to help me raise it up a touch.

im finding it all very confusing , but great reading

The only way you can get to 150 PSI+ is with low porting and a factory head milled .120" or so. A custom head with tiny pockets is needed to make up for high porting. The reason is compression is not generated until the exhaust port closes. So, the higher the porting, the lower the top end compression reading.

To confuse matters further, physics and architecture conflict in every engine. Consider that less swept volume (tall porting) combined with tiny combustion chambers means less air/fuel mixture available for combustion. Less air/fuel mix limits available power production.

Get it now?