1999.9 -2005 (VW MK4 8 valve) Stage 3 Ported Intake Manifold DevelopmentDyno Testing the VW Golf / Jetta 1993 -1999 (MK3) and VW Golf / Jetta 1999.5 -2006 (MK4) 8 valve intake manifolds.  Stock/OEM form vs all out ported. 
As with all good upgrades, proven dyno results are key to show improvements.  The results are often surprising as they are in this test case.
The test car is a VW Corrado, with  a all motor ABA 2.0 swap.
Motor information: (none of this will change during the testing)
95 OBD1 ABA block, stock bore, stock rods and pistons, fresh rings and bearings, ABA windage tray style oil pan gasket and 16V oil pump and dizzy blockoff
95 OBD1 German casting cylinder head, milled .025", street port and good 3 angle valve job, new valve seals, TT heavy duty dual springs, TT272 hydro cam.
All components checked for spec and engine cc'd at 10.29 to 1.
MS2 v3.57 ECU running extra firmware v2.10.
GM waste spark copilpacks for ignition directly controlled by the MS.
New Ford motorsport 24lb/hr blue top injectors
AMK stainless 4 into 2 into 1 header, 2.25" pipe with a dynomax bullet as a resonator and a stainless round muffler.
Stock OBDI throttle body.


MK4 Flow Tests
Upper and Lower sections tested together. Each runner tested individually, with all vacuum ports plugged. Air was pushed in through the TB opening. Flow is measured in inches of water, Lower numbers indicate better flow. Low numbers are indicate less restriction and better air flow.


OEM/stock MKIV
Runner #Stock Flow

Runner 113.5”
Runner 210”
Runner 310”
Runner 410.25”

Stage III Ported MKIV
Flow is measured in inches of water, Lower numbers indicate better flow. Low numbers are good.
Runner #Ported Intake Flow
Runner 19”
Runner 29”
Runner 39”
Runner 49”

Wheel HP / Wheel TQ results
Nonported MKIII - 107.58whp / 114.03 wtq
Ported MKIII - 107.18whp / 113.62 wtq
Nonported MKIV
- 110.85whp - 119.76wtq
Ported MKIV - 112.29whp / 119.62wtq