Boost Leak detection FOR CHEAP!, found this, thought I would post Options

[easternpiro1]

Boost Leaks, while easy to diagnose and fix, are often over-looked by turbo car owners for one reason or another. Whether they are overlooked because of laziness or ignorance, they rob power from your turbo car and cause it to perform at much less than its potential. In this article we will discuss not only why and how boost leaks could be holding your car back but also how to make and use your own boost leak tester.

Any air leaking out of the plumbing system from the compressor side of the turbo to where the intake manifold meets the head is considered a boost leak. In a vaccume condition like at idle, air would be being sucked in through a boost leak, and in a boosted condition like full throttle air would be blowing out of a boost leak.

Most turbo cars use an air flow sensor to meter air as it is brought into the turbo. As air passes through the air flow meter, it is counted and the ecu assigns a certain amount of fuel for that amount of air. Lets consider a hypothetical situation of a particular boost leak. Air passes through the air flow sensor, is measured and counted, and the ecu assigns a certain amount of fuel for that particular amount of air. As the air passes through the turbo and begins its path to the head, some of it escapes through a boost leak, (in this hypothetical situation we will use a bad throttle body gasket as an example of a boost leak). The air escaping through the leak was measured and considered in calculations when the ecu assigned the correct amount of fuel for the mixture, but the ecu does not know that some of the air is leaking out through the damaged gasket, and does not adjust for it. In this situation less air will actually be reaching the engine than was metered, and the fuel will remain unchanged, throwing off the tune and causing a rich condition. This rich condition will cause your car to run at less than its potential.

Not only will this rich condition cause your car to run at less than its potential, you may notice that your car has trouble holding boost through the gears at wide open throttle. Throwing off your tune, and not being able to hold boost is enough to make you lose a great deal of power that your car should be making.

Boost Leaks arent only harmfull to cars with airflow meters though. Any turbo car could potentially be harmed from boost leaks. Boost leaks make the turbo work harder to do the same amount of work, and could lead to a turbo failure because of it. To demonstrate this, imagine building pressure in a baloon by blowing air into it with your mouth. Then make a tiny hole in the baloon and try to blow it up again. You will notice you are doing more work than you did the first time to inflate the baloon to the same size. Hopefully this section has motivated you enough to check your car for boost leaks. Now on to how you can make a Boost Leak Tester with parts readily available at your local hardware store.



To assemble, just put everything together as shown

To get the valve stem in, drill a hole in the PVC cap.

How to build an Intercooler Pipe Pressure Leak Tester
Parts Needed:

A 4 inch long piece of 2.5" O.D. (outside diameter) hose. (I used some radiator hose I got at NAPA)
1.5" I.D. (inside diameter) PVC end cap.
2 band clamps that will fit around the 2.5" pipe above.
A valve stem (I used the rubber type you press in)

Note that if you have a larger turbo, the sizes of the end cap and hose may need to be larger in order to fit the turbo inlet.



To use it, just remove the intake pipe from your turbocharger inlet, and attach this in its' place.

Now you need to hook something up to the valve stem to pressurize the intake so you can listen for leaks. I use a 7 gallon air tank I got from Walmart, I just fill it up with air at the local gas station. You can also use a simple bike pump.

If you have a manual boost controller hooked up, you might want to plug off its' intake hose, as they leak a lot of air, making it hard to pinpoint the real leak.

Pressurize the system, and listen all over for leaks. Make sure you or a friend listens under the bumper too, wherever there is IC piping.

A leak will be obvious, they make a loud hissing sound.

You might want to have a friend check out your boost gauge while you are pressurizing things, to make sure you don't put too much pressure on things. (20 psi should be safe, or whatever you run safely for boost)

Places I have heard of leaks occuring:

BOV flange
Intake manifold ports
Throttle Body gaskets
Holes in the intercooler
Holes in the intercooler piping (sometimes the rubber pipe inside the stock woven mesh pipes cracks, and you can't see it from the outside... the pressure tester will find it though!! )

[easternpiro1]

maybe sticky? (i have no shame nominating my own post for a sticky...lol)