Quote:
Originally Posted by Virtual Factoid
Hassmaschine & E92_William: So I did the 328i to 330i With MAF tune as I mentioned before. I ordered new DISA valves just because I didn't want to take apart the intake manifold anytime soon with a refurbished DISA failing on me. Even though I had new DISAs, I decided to test them with INPA. They both tested fine, I was able to fully open and fully close them with INPA commands. I tested them both one at a time connected to the DISA-2 connector only.
Here's what's concerning: when I tested directly by revving up the engine, it did nothing at all. It was fully open ALL the time all up to 5K rev band. When the heck is it supposed to close, even if partially? At this point it seems to be a placebo effect going into all the trouble to replace the manifold if it is going to stay at 100% open position. Isn't the 328 manifold with no DISA valves effectively the same as a 330 manifold with the value always open? What am I missing here? Or does all the magic happen on the DISA-1 connector only (which I did not test)?
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1st stage - idling/lower engine speed range
At idle speed and in the lower engine speed range, the DISA actuator motors 1 and 2 are closed.
The intake air flows past the throttle valve into the resonance pipe. In the resonance pipe, the intake air mass splits. The air is fed via the collector pipe and resonating pipes into the individual cylinders. In this way, three cylinders are provided with a comparably high air mass.
2nd stage (Approx 3000 rpms) - medium engine speed range
In the medium engine speed range, DISA actuator motor 2 is opened.
In this case, it is assumed that the inlet valves of the first cylinder are just closing. The gas motion creates a pressure peak at the closing inlet valves. This pressure peak is passed on via the resonating and collector pipes to the in next cylinder in the firing order. This improves the filling of the next cylinder to be charged.
3rd stage (Approx 4300 rpms) - upper engine speed range
In the upper engine speed range, both DISA actuator motors are opened.
In this case, it is assumed that the inlet valves of the first cylinder are just closing. The gas motion creates a pressure peak in front of the closing inlet valves. The intake air mass is now fed via the resonating, overshoot and collector pipes.