Assuming you have no other use for the vac connections (boost gauge etc)...
Wrap some tape around a short bolt, put the taped bolt into the end of a short piece of hose, then put the other end of the hose on the spare connector.
Wrap some tape around a short bolt, put the taped bolt into the end of a short piece of hose, then put the other end of the hose on the spare connector.
In the absence of a reply I've made my own:
If anything in this picture is wrong please correct me as I did this from sight.
A couple of questions:
1. There is a vac pipe that comes out of the N249 and loops back round into it through what I think is a non-return valve?
2. There is a pipe that comes off the pipe above that runs down under the inlet manifold, where does this go?
3. Why does the carbon can have a vac connection?
The charcoal fuel tank breather vents to the intake system to burn off any residual fumes.
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Muttley, that is absolutely bloody superb mate, cheers!
So if I wanted to completely remove the N249 as some others have (I'm going to just try bypassing it first) I could just block up the line that runs from the left hand underside of the intake manifold to the N249 loop back hose?
So if I wanted to completely remove the N249 as some others have (I'm going to just try bypassing it first) I could just block up the line that runs from the left hand underside of the intake manifold to the N249 loop back hose?
Assuming the dump valve needs no external control input to perform its normal function i.e. that the valve itself detects the pressure rise in the inlet manifold and mechanically opens to dump the excess back into the turbo inlet. I think that is the case.
There are three lines out of the N249 box, one to the dump valve, one to the vacuum reservoir and one to the intake. The intake is the source of vacuum, and will pump out the vacuum reservoir during idling and low speed running. The vacuum reservoir seems to be connected to the N249 valve only; I'm guessing that it's there to allow the ECU to operate the dump valve when the throttle is fully open, or nearly so.
I guess you're proposing to block the hose from the inlet manifold? Make sure to block it on the manifold side, so that you don't leave a leak into the manifold.
There are three lines out of the N249 box, one to the dump valve, one to the vacuum reservoir and one to the intake. The intake is the source of vacuum, and will pump out the vacuum reservoir during idling and low speed running. The vacuum reservoir seems to be connected to the N249 valve only; I'm guessing that it's there to allow the ECU to operate the dump valve when the throttle is fully open, or nearly so.
I guess you're proposing to block the hose from the inlet manifold? Make sure to block it on the manifold side, so that you don't leave a leak into the manifold.
That's my intention yes, cheers for the input. Now I just need to work out the best place to connect the DV to, I think some people have connected a 'T' piece to the FPR line although I know others have connected directly to the top right of the inlet manifold where the connection is to the carbon can. Any idea if it would cause problems with the carbon can to do this by blocking off its connection to the inlet manifold?
Why not plug it directly into the inlet manifold? Don't block that nipple you were talking about (the one that feeds vacuum to the N249) and plug a hose that runs to the DV.
Sorted, thanks for your help everyone.
Any issues with heat and the silicon hose around the inlet manifold?
No, silicon hose will cope with temps a lot higher than those given off by the inlet manifold.
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?
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?
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