DV vacuum question

[Leach01]

Hi, met with a mate that had the same engine as me today and my dv vac works off the ome pipe and his runs off the fuel pressure regulator?

Why is this and is there a benefit?

[gazareth]

hi whats the ome pipe?

[Chris.]

2 nipples under the inlet...one for the fuel regulator, one for the dump valve

If hes running the 2 off 1 pipe...its plumbed up 'wrong'   - used loosely.

[Leach01]

Ok, basicly the factory pipe is blocked off and there is a T pice on the fuel regulator vacume pipe. The DV is plumbed in with the fuel regulator? He said that it's a common thing to do and that at show a lot of people had this?

[Chris.]

not really.  Probably doesnt know what hes talking about.

You want a undisturbed line to the fuel regulator....people commonly 'T' off the dump valve vacuum pipe to run a boost gauge.

There is no benefit of doing what he has done.  Fact.

[1.8Tgolf_Chris]

sounds like n249 bypass mate

[Chris.]

You wouldnt do the N249 bypass like that anyhow?

[WadGTI]

You wouldnt do the N249 bypass like that anyhow?

Not sure why not Chris?

I have mines t'd between the FPR and DV. No issues, no fault codes, car boosts and runs spot on. Never had one surge.

[Ben@VWH]

You wouldnt do the N249 bypass like that anyhow?

Not sure why not Chris?

I have mines t'd between the FPR and DV. No issues, no fault codes, car boosts and runs spot on. Never had one surge.

The reason you don't T into the fpr pipe is that it's rising rate. Basically it raises fuel pressure to match the increase of boost pressure. For every bar of boost you run the fuel pressure increases by 1 bar. You keep the vacuum line to this as short and direct as possible so the regulator can quickly increase the pressure so you dont run lean, longer the pipe, more chance of leaks and also more space to fill so increases the time it takes for the fpr to enrich the engine under boost.

Chances are it wont make a difference to the majority of cars but it's just something you don't do, pointless risk really.

Hope that helps. 

 

[1.8Tgolf_Chris]

as far as i know when you do the n249 bypass u have the line from the oneway valve into the inlet, so that only leaves one more line from the inlet to the fpr and Dv, unless you T in the oneway valve line but not heard of anyone doing that, so how u meant to run fpr on its own