Managed to do a boost leak test today.

I pump in about 10psi of pressure into the system right before the turbo.

There is no hiss sound but the pressure seems to slowly return to 0psi.

Is this normal in a non-leak situation? Or the pressure should hold at 10 psi if there is no leak?

 

it will leak past your valves that are open

 

try to go a little higher in pressure, maybe like 15. if there is no noise than i wouldnt worry about it.

 

so does this mean that it is normal for the pressure to leak slowly away even though there is no leak in the system? If there is a leak, I assume the leak will be very fast?

 

it's normal. it will not going to stay at 10 psi. some of the leakage are hard to hear unless you really pay attention. sometime you sould pump a little more like 15+ psi.

 

yes it is normal for it to slowly leak down. and do turn up the pressure some more, it can take the higher pressure to find the leaks around the clamps

 

Folks, managed to do another test today.

I bought a 12v DC air compressor which plug into the car cigarette power.

The funny thing is, the pressure cannot seems to go higher than 10psi!!!

The air compressor continue to work but the pressure seems to maintain at 10psi. The compressor is rated to 250 psi!!!

I use my hand to feel all around hoses, piping, BOV, intercooler coupler, turbo inlet but cannot find any siginificant leak and there is no leaking sound from anyway. I also crank the Forge RS BOV to maximum tension.

The only place which have some minor air rushing out is the 2 outlet on the engine block. (refer to pics)

Anyone has any idea what could be wrong? Actuator? Any idea? Is the pump too weak for this application?

 

OK, if the presure is staying at 10 psi on your little pump... the loss of air volume has caught up with you input of air volume. Presure is just the input of more volume that the space that is currently being taken up by the existing volume resulting in an increase of presure. Your pump is not strong enough to move enought volume to increase the pressure high enough.

example:
if a hole is this big o it might lose 1 gal of air every minute at 5 psi or 2 gal per minute at 10 psi.

if a hole is this big O it might lose 3x that.

your compressor might only put out 2 gal per minute and the leak has matched the input volume at 10 psi.

If the places circle are the only places that are leaking than that is strange to me. Assuming that you are putting the air into the compressor side of the turbo and not into the airbox end of the air intake tube. The upper circle is the tube from your valve cover to you intake tube. I would not think that would be an issue if you are testing correctly?

 

ok thks...that's what I thought. Maybe the little pump is the problem. Anyway, it is just a 10usd dc pump.

The circle(s) in the pic are hoses which connects to the intake pipe. I remove the hose when I take out the intake. I pump into the turbo inlet.

The method and tools that I used is as per the below URL...
http://www.dsmtuners.com/forums/showthread.php?t=169435

Do you think I should stuff something into the (circled) outlet for the pressure to increase further? Do I should just use a stronger pump?

 

you should just need a stronger pump.