You must be logged in to rate content!
5 minute read
OEM Intake manifold dyno ~ MKIII vs MKIV
Compliments of tdogg74 @ www.vwvortex.com
Special thanks to Prof315 for his dedication to dyno test these for us and ny_fam for providing the test subjects. Purpose of this thread: To show the hp/tq differences between:
Stock MKIII intake manifold
Ported MKIII intake manifold
Stock MKIV intake manifold
Ported MKIV intake manifold
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.
Intake manifold info:
ABA OBDII Intake Manifold
Lower runner length is 6.2" long
Port inside diameter 32.5mm (head side)
Port inside diameter 34.5mm (opening connecting to upper manifold)
Single runner volume 150cc
Upper manifold section
Port inside diameter 34.25mm (opening connecting to lower manifold)
Runner length 3.875"
Plenum Volume 1.8L
MK3 upper manifold backside
AEG Intake Manifold
(MK4 with same intakes AEG, AVH, AZG, BEV and BBW )
Lower runner length is 6.0" long
Port inside diameter 32.8mm (head side)
Port inside diameter 40.0mm (opening connecting to upper manifold)
Single runner volume 150cc
Upper manifold section
Port inside diameter 39.8mm (opening connecting to lower manifold)
Runner length 8"
Plenum Volume About 1.8 -2.0L (internal brace was in the way)
MK4 upper manifold backside
Flow Tests
Stock MK4
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 good.
OEM MKIV
Runner #1 - 13.5"
Runner #2 - 10"
Runner #3 - 10"
Runner #4 - 10.25"
Stage-1 Ported MKIV
Flow is measured in inches of water, Lower numbers indicate better flow. Low numbers are good.
Runner #1 - 9.5"
Runner #2 - 9.5"
Runner #3 - 9.5"
Runner #4 - 9.5"
Stage III Ported MKIV
Flow is measured in inches of water, Lower numbers indicate better flow. Low numbers are good.
Runner #1 - 9.0"
Runner #2 - 9.0"
Runner #3 - 9.0"
Runner #4 - 9.0"
Ported MK4 lower picture
Flow tests are done with a Manometer.
About the manifolds:
It wouldn't be easy to bolt a mk3 upper manifold to a lower mk4 manifold. The bolt patterns don't match, and the ports don't align properly.
The lower sections of the mk3 and mk4 manifold are where the flow restrictions are. Note the mk3 manifold and mk4 have the same size port openings to the head.
MK3 top/ MK4 bottom of picture
WHP / WTQ 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
DYNO RESULTS
MKIII unported - BLUE
MKIII ported - GREEN
MKIV unported - ORANGE
MKIV ported - RED
OEM vs PORTED MKIII
Bigger - http://farm3.static.flickr.com...o.jpg
OEM vs PORTED MKIV
Bigger - http://farm3.static.flickr.com...o.jpg
ALL MANIFOLDS
Bigger - http://farm3.static.flickr.com...o.jpg
*NOTE*
During the MKIII dyno tests, it was determined that there was a throttle cable issue and that that might have scewed the numbers. Once the throttle cable issue was corrected and re-dynoed, the results were more or less the same. The original MKIII dyno results were used in this thread.
