Anyone have any experience in smooth boring an thier plenum? What kind of Hp gian, how hard, is it really worth it? Thanks to all for the info.

 

Come on guy's..... someone has to know something about this???? I saw a picture of the inside of our plenums and they look as rough on the inside as the outside.

 

I have thought about sending off my Injen intake and Intake Manifold for this.
http://www.extrudehone.com/afmpro.html

 

WOW!!!! $400.00 bucks. 2-3 weeks for delivery also. Do you have any idea how much HP you can get? I'll have to save up for this one. Thanks.

 

I had That done on my 5.0 mustang cobra intake picked up about 11 hp and 9 ft pounds of torque at the wheels but I have heard of even better results, might need to bump the timing a bit though the 5.0 gained another 10 hp by going 2 degrees higher then before the intake honing, if raised before the intake honing it didn’t make any more power the base timing of 14 degrees.