Boost gauge connected to bov vacum line. Wrong readings?

[Chris_Sag]

In my 2g the aftermarket boost gauge is connected with the t-fitting into the vacum line for the BOV. Does that make false readings? To mutch or to low boost? And is that the reason for some big spikes on the gauge when i go off the pedal?
Should i rewire it to the FPS or is'nt the difference that big?

 

[9!'clipseDOHC]

In my 2g the aftermarket boost gauge is connected with the t-fitting into the vacum line for the BOV. Does that make false readings? To mutch or to low boost? And is that the reason for some big spikes on the gauge when i go off the pedal?
Should i rewire it to the FPS or is'nt the difference that big?

Yes you should change it to the fuel pressure regulator vacuum line right away. You shouldn't tap anything (gauge or MBC) into the BOV line.

 

[Chris_Sag]

Because of the function of the BOV or wrong readings?

 

[agentorange313]

You should be getting a correct reading if the BOV is connected to the intake manifold, vacuum source.

I agree with 9!'clipseDOHC though, I think you should tap another source for the boost gauge. When I first installed my boostgauge I tapped the FPR vacuum line. I put a t-fitting in there and ran the boost gauge source from it.

Now I have a vacuum block and each item (BOV, FPR, PCV, Boost Gauge) all have there own port to get a boost/vacuum reading. I think t-fitting in vacuum line,you are only asking for problems and boost leaks.

 

[JAX2Ganey]

+1 on using the fpr vaccum source.

 

[9!'clipseDOHC]

Because of the function of the BOV or wrong readings?

I know that it's not good for the operation of the BOV, not sure about the readings or not. Either way, I would switch it to the FPR as soon as you get a chance.

 

[agentorange313]

like I said before the BOV works off of vacuum. I went as far as to place a check valve between the bov and the intake manifold. Check valves are a great way to ensure the proper operation of vacuum activated parts. plus an extra one in the pcv line helps a lot, factory ones suck.

I dont like the idea of the the diaphragm in BOV to be exposed to extreme boost/psi pressures. The check valves ensures proper operation.

 

[GsXdSmKingGsX]

Why would make it go so far out of its way? If you looked it up the FPR line is the one most people use.

 

[ramsack]

like I said before the BOV works off of vacuum. I went as far as to place a check valve between the bov and the intake manifold. Check valves are a great way to ensure the proper operation of vacuum activated parts. plus an extra one in the pcv line helps a lot, factory ones suck.

I dont like the idea of the the diaphragm in BOV to be exposed to extreme boost/psi pressures. The check valves ensures proper operation.

The BOV relies on boost from the line running to it to help it stay closed during boost. Both sides of the diaphragm are seeing almost equal pressures, and preventing the line side from seeing boost is making the closing force weaker and putting more strain on the diaphragm. I don't even see how it functions at all with a check valve in there.

 

[agentorange313]

sorry, I dont want to spread false information

I should have posted that I use it because I have the synapse BOV, with the c port for the boost source.

It has designated pressure/vacuum ports.

 

[ramsack]

What you would want then should be something like Toyota's VTV, which allows full flow in one direction but highly restricts it in the other direction.

 

[dsmtnr]

FPR vaccum source is the only safe way to go.