No I did it from above, disconnected the ball joint on the electric actuator you can just see it/get a pry bar in carefully. I then pushed all the swirl flaps hard open (even when the bar is across, there is some small movement on each one) and tie wrapped the bar to a waterway metal union near the cambelt end in the middle of the head, basically they are tied in the fully open position.
As for their use, I'm not sure, they do increase swirl but they decrease flow and reduce air, they also increase pumping losses which reduces efficiency. some cars have them one year and not the next, so the difference cannot be a massive one. I really do not know the answer to this. What I can say is:
The engine sounds a ton better, if you close the flaps the car sounds naily and knocks more you can feel that the combustion is not being cushioned by sufficient air and the shock waves are hitting the cylinder more, it revs up better and cleaner without sounding rough and it's noticably quicker off the mark. Also it's smoother and quieter, finally the turbo used to whistle hard and make a bit of a squall when lifting off the throttle, now it's much quieter - this happens because the turbo can flow more air and isn't having to force the air against a brick wall of half the passage ways closed basically, it sounds/feels/runs a lot happier.
The ONLY thing I can say is I do not know if it would affect soot and/or dppf clogging, but it certainly runs better. As my dpf will soon be for the bin I don't care.
On the basis of the experiment, I'd like to remove the manifold, clean the gunk of the egr out, take the flaps fully out and core plug the spindle holes. This will eliminate any chance of a flap breaking into the engine and it will also flow better as it won't have flaps (albeit open) stuck in the middle of a small passageway.
Greg.
When you dissabled/disconnected your swirl valves I assume? that all you did was disconnect the ball joint and arm linkage that goes to the bottom of number 3 swirl valve?
I'm also guessing that you had to do this from underneath the car as I found it impossibel to get over the top of the engine to the actuator due to the big overhang the inlet manifold has and the closeness of the actuator to the back of the block?
Also how do you hold the swirl valves in the open position? The actuator spring return would normally do that. Are are the stiff enough to just rest in the open position and not move over time with engine vibration?
Finally you say yuo find the car more responsive at low RPM with the swirl valves open. This sounds contrary to their original design purpose. Maybe this is why the MkII Cromas don't appear to have swirl valves.