N249 and vac resevoir removed - spare vac connectors.

[skahigh]

As I understand it, the N249 valve allows the ECU to operate the dump valve at times other than upchanges, for the release of excess boost if it should detect such a condition. I don't know if that's a regular occurrance, but LC/LCR owners on here have reported an improvement in dump valve performance and other benefits from removing the N249 function.

Dave, from what you say the dump valve does require a connection to the inlet manifold even if the N249 is bypassed. I wasn't sure if this was the case, but looking at the vac diagram shows that there is a direct path in the factory setup. Does the dump valve require vacuum to operate, to suck the piston open, or does the piston open and shut by direct mechanical/pneumatic action, the pressure differential operating the spring in the valve to open it? Any idea where there would be an expert answer?

The vac diagram you supplied is superb, I can literally disconnect the n249 from the inlet manifold and dv and then run a vac line between the dv and inlet manifold. At that point the N249 and vac resevoir are totally redunant in the system. If it works for me I will be replacing the N249 with a resistor and removing the whole setup from the top of my engine for aesthetic purposes.

 

[skahigh]

Woohoo, N249 successfully bypassed! Was a bitch getting to the connector under the inlet manifold, I had to remove the charge pipe.

Also, those one use clips are SOOOOOO IRRITATING!

Now I just need to work out how to wire a resistor in in place of the N249 so I can remove the whole lot.