xr4tic

From VW Vortex

Numbers I pulled off of the graphs:

Large port (AEB) vs. small port Intake
.050" I: 55 CFM, 52 CFM
.100" I: 102 CFM, 98 CFM
.150" I: 138 CFM, 127 CFM
.200" I: 165 CFM, 145 CFM
.250" I: 180 CFM, 152 CFM
.300" I: 190 CFM, 155 CFM
.350" I: 202 CFM, 158 CFM
.400" I: 205 CFM, 161 CFM
.450" I: 208 CFM, 163 CFM
.500" I: 210 CFM, 165 CFM

Large port (AEB) vs. small port Exhaust
.050" E: 38 CFM, 37 CFM
.100" E: 73 CFM, 73 CFM
.150" E: 102 CFM, 102 CFM
.200" E: 127 CFM, 126 CFM
.250" E: 145 CFM, 138 CFM
.300" E: 153 CFM, 149 CFM
.350" E: 163 CFM, 153 CFM
.400" E: 169 CFM, 162 CFM
.450" E: 174 CFM, 164 CFM
.500" E: 176 CFM, 166 CFM

Just further proof non-DBW is better <ul><li><a href="http://forums.vwvortex.com/zerothread?&amp;id=1102510">http://forums.vwvortex.com/zerothread?&amp;id=1102510</a></li></ul>

xr4tic

Stock Lift:
I: ~0.302"
E: ~0.366"

Schrick Lift: (from post below)
I: 0.323" (8.2mm)
E: 0.409" (10.4mm)

So I guess this shows that Schrick cams won't have as big of an effect on small port heads vs. large port heads

Brent V

but wouldn't the fact that the exhaust port seems to be the restriction that the large port head is really only &lt;10 CFM better at flowing?

If the intake is 45 CFM diff, where does all that extra intake go if it has to blow out the exhaust eventually?

Brent V

for brevity, why's the intake so much bigger than the exhaust?

xr4tic

but the piston pushes the exhaust out.

At least for NA applications.

Keep in mind, that these are flows vs. lift, so you'll notice the exhaust has higher lift, and a cam also dictates how long the valves are open, so the exhaust is usually open a little longer.