Removing restrictive VTCS from intake manifold
Since I have to wait for more parts before continuing the turbo installation I decided to remove the intake manifold.
This makes it easier to properly block the EGR and remove the restrictive VariableThumbleControlSystem.
While dismantling the intake I took a closer look at oil deposits from the breather hose.
No oil on the outside of the TB but on the inside was another story.
This is probably normal. The breather hose from the cam cover sucks oil fumes at vacuum.
As long as the intake piping is clean I’m happy.
The bottom part of the intake was a real b** to get off. I had to invest in some new 1/4” pipes and stuff to reach the bottom nuts. Nice and roomy when the intake is off. Lots of wires.
The VTCS is springloaded and fully open at default. When there is vacuum the “throttle-plates” closes and chokes the air while making a tumble effect. I have no idea why. It might aim atomization of the intake charge at idle and make a cleaner combustion.
Anyways, it restricts flow and has to go.
The EGR can not be used with the ETD manifold.
My original plan was to remove the valve completely but that might throw some obscure CEL/sensor problem. Instead I made an aluminum block off plate for the EGR intake port and let the valve stay put and connected to the harness.
The VTCS is easy to remove but I did not figure out a proper way to seal the holes that are cross drilled trough all runners. I thought of using liquid metal but the fear of it coming loose made me do a simpler solution. I think the only proper solution is to weld the holes and grind the welds.
I ended up cutting the end part of the rod to seal off the manifold at the end and keep the holes. I think the turbulence of the holes is a much less of an restriction than the VTSC. I will not do a lot of job on the OEM manifold for minimum gains. A new manifold and 7xmm TB would be time(=money) better spent.
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