CNC ported TB VS hand polished TB
 

Whats the difference in performance and HP between the two?

polishing the inside of a TB actually hurts airflow first off, and the VMax ported TB is proved to be the best on the market.

Same difference as with hand ported cylinder heads and CNC cut ones.

You have hit on a subject that has seen a lot of trafic. The short version is the VMax CNC ported throttle body is 100% repeatable due to the accuracy of modern CNC machinines. They did the R&D time to come up with a porting job that produces fantastic throttle response and yes some power. No porting job will produce huge power it is just not possible, but VMax produces what is available. The much more valuable part of the porting is crisp precise throttle response. I saw it as part of a "breathing package" for my LS motor. Intake, scoop, washer relocate, and ported throttle body. That took care of the inhale. ARH long tubes and Corsa took care of the exhale.

The engine wont care how the shape was made. The whole point of having a CNC program is repeatability and time - its highly repeatable and takes practically "no" time compared to performing the action by hand.


And FYI NASCAR heads do the initial porting on a CNC and they finish off the porting by hand... there are just certain spots the CNC machine cant reach very well.

All the VMAX throttle bodies are CNC spiral ported for consistency. Not saying hand-ported ones do not work, but there is always a human error factor involved. Actually out of the hand-ported TB's my first choice would be Bo White...

Back to back dyno graphs comparing Stock to VMax.