Intake Upgrades

[SappySE107]

Ported TB/Plenum

The stock TB plate is 64mm, and to the best of my knowledge a 69mm plate is the largest that will fit without welding up passages in the TB. Aside from the plate itself, it is a good idea to grind the opening part of the TB to be bell shaped. This will reduce the turbulence in front of the TB plate. The lower part of the plenum that mounts to the lower intake is chore, since the ports don't come close to matching the gasket. Extrude Hone would be the best bet for the plenum since it is the only* way to get to every part inside the plenum. Hand porting to match the plenum to the lower would be worth doing as well.

Stock gasket to plenum

The lower intake also doesn't match the plenum gasket, and should be matched. Porting to match the head may have poor results due to the velocity change from having to match the head as well (opening it up).


94+ Mass Air Flow

#350114. The box will be labeled Buick "Roadmaster & Roadmaster Estate Wagon"
http://www.granatellimotorsports.com/gmmafautomotive.htm

*Cutting up the plenum will also work, but requires welding.

[z34phoenix]

I have seen on my 96 DOHC that gasket matching the lower intake manifold yeilded very nice results. my belief is that turbulance is reduced in this transition. the first pic is my finished manifold. the second is of the carbon buildup where the parts werent matched.