SudzRA

iTrader: (2)

Did some quick searching, couldn't find an answer to this. To the people running a boost gauge, which vacuum/boost line have you been tapping into? My first thought would be to tap into the line connecting the bypass valve to the intake mani (just put a T in the line). My second option would be to tap into the line for the FPR boost reference, which would let me know instantly if it happened to to come off under boost. My third option was to T into both lines, run a hose between these two Ts, with a T in the middle which runs to my boost gauge. This would let me know if either line came off.

What do u guys think?

bossssman38

iTrader: (2)

There are answers on this somewhere. It might be buried in a thread though. So to answer your question: option 1

Mad_SB

iTrader: (8)

DO NOT do #3, either do 1 or 2.

03chi-town0Z

iTrader: (7)

I'm running option 2 (fpr hose) with an AEM analog boost gauge

omegis

iTrader: (2)

+1. Pretty sure I did the same thing. All I know is it matches my AEM gauge matches my datalogs.

gkania

iTrader: (6)

Using the line to the BOV and not to the fuel pressure regulator is always the best policy.

SudzRA

iTrader: (2)

Option 1 is what I was leaning to. Mad_SB, could you shed some light on why not to use #3? I figured since both lines draw pressure from the intake mani, they should see the same pressure.

richardjh

I think the issue with #2 is that, in the event of a fault with the new boost hose connection, the fuel pressure regulator won't see its proper boost reference.

Which is a really Bad Thing at WOT.

Nobody wants to sacrifice their engine for the sake of a gauge that is ostensibly there for safety reasons!

Rich

03chi-town0Z

iTrader: (7)

Agreed, however I have seen cars running #1 setup with bpv opening/fluttering and compressor surge issues. My guess is that there were other factors involved that I don't know about, as well, I just know that it's happened.

As far as running at the FPR, with my AEM gauge at least, there is only a very short (4", if that) hose needed at the T and then it connects right onto the electrical sender portion. That way there are only wires, not hose, running the length of the engine bay, minimizing the possibility of pinching/cutting/burning/etc. the vacuum source hose.

javicracer

iTrader: (82)

u can do more options but the # 3 is a no no.

omegis

iTrader: (2)

Take back what I said earlier. I did option #1.

javicracer

iTrader: (82)

i dont see any problem running the gauge from the FPR, thats how mitsu run it on the rs and mr cars.

richardjh

Noted!

Rich

Mad_SB

iTrader: (8)

Because you introduce yet another way for the FPR reference to fail. I have seen at least 3 or 4 "boost gauge leaks" in the past. When you have a leak in the line that feeds the FPR you go lean under boost and rich off boost.

While it is true that #2 will also let you know of the FPR line pops off.. a wideband will also do that without introducing an additional point of failure (the line from the T to the boost sensor, be it mechanical or electronic). #3 is the worst of both worlds in that you now have 3 potential failure points and any of which will result in lean in boost condition.

Mad_SB

iTrader: (8)

Thats probably about the ideal setup... no long run of vacume line to fail and you will know if an issue does develop with the lines.