This photo may help. Its taken looking up into the engine compartment after the engine and trans have been removed. You can see the intake pipe coming in at the upper left, splitting, and then winding around to go to the compressor intakes. Never mind the soot - I had an exhaust leak.

I can't see how this thing is accessible with the engine in place, but maybe somebody else can.

Jon

 

needs some help, as will need to do this test in next few days...

• To test the TB and injectors, plug one end of the Y and push air into the other.
• To test the rest of the system, for non-fenderwell set ups, pump air into the turbo inlet (3.5inch plenum post MAF). This is equivelant to plugging one inlet at the turbo and pressurizing the other but allows ICs to be tested as well.

Questions:

1. do i have the above correct?
2. what's the maximum of pressure that should be used? I see 25lbs mentioned, I was thinking 1.4bar just above my car's intended max boost. Guy that works at porsche dealer told me 0.5bar is enough.
3. Should the system be pressurized to X psi/bar, at which point, if the pressure holds, is confirmed diagnosis that the system is air tight?
4. or should we expect the system to leak (from various places), and thus regulated air at Xpsi/bar is required? Then simply listen for leaks and use soapy water at connections?

Thank you!

 

I was refer to this awesome thread by jpflip.

I've now built my Home Depot PVC plug with pressure gauge and tire inflater.

Now I need an air compressor. How big a unit do I need? I think the inexpensive small ones won't work. Maybe a 5 Gallon one? 10 Gallon?

 

Even a smaller one can do the job because you need to pressurized only about to 14 pounds. (1.0 bar....). If you put too much pressure it will come out of the oil filling cap. Of course if you buy a bigger compressor it will be useful for other jobs.... And also bigger tank , the compressor will not start all the time and you will be able to track the leak more easily without that noise....

 

Thanks again JP.

I think your comment "you will be able to track the leak more easily without that noise...." is key. I've got a relative lending me and hauling a 50-gal unit over as I speak...

You said 1.0Bar and 14psi. Others have said 20 to 25 psi in this thread. Any comments on the differing opinions? Others are welcome to comment too.

I have a 1.0 bar flash and the issue I'm trying to track down is a "perceived" lessening of power at max boost compared to what I remember it as before an engine-out service. I still see 0.9 and 1.0 bar being hit but it gets there a little slower than what I remember and maybe not as high (I think I saw occasional spikes to 1.1 before and now I never see that). So I'm thinking a boost leak only at the highest end (engine runs smooth at all rpm; no issues except what I "think" is less maximum power than before).

 

i have tested several 996tt systems i use a bostitch 2hp 6 gal 3.4 cfm compressor and test mostly protomotive systems to 28 psi with it

tim

ps i bought this compressor at costco its a pancake style cost about $150

 

Great tip!!! Tks

 

I have to admit I was not able to reach 25 pounds, too much air coming out of the oil fill cap. But I remember just hitting the starter to rotate the engine a little bit and got less air coming out.... And I have found many small leaks even at lower pressure. I also had to lower the engine to reach the lines in the forward section of the engine compartment. It was too tight in front and there was a strong leak.....

lowering the engine : https://www.6speedonline.com/forums/...-engine-2.html

 

I have same problem. When I tested at 25psi, air leaked a lot via oil cap. Its noise was loud and should cover any small leak I might have. It was pretty doable at 15-18psi. How do your guy do at 25psi?

 

Try pushing down on the oil cap or wrapping a rag around the edge of the oil cap to reduce the hissing noise. Helps to hear if there are leaks anywhere else...

 

The repair manual says that you should not go higher than 1 bar.

 

What if your leak doesn't leak at 15psi but leaks at 20 psi and you have a 1.4+ bar tune? You should test to at least 25psi.

 

my intake is made of reinforced silicon like the one in the picture...we are worried its collasping on top of the engine...

The car boosts 0.53 and holds flat if you keep accelerating, it does not move up or down at all...

We pressure tested car and found a leak with the oem lower boost hose on driver side...the agency hose was too short so we use the oem one. They are working on fixing this now...but that this alone is causing the problem...

 

Here's my rig:

I used this cap from Home Depot:
http://www.homedepot.com/Plumbing/h_...atalogId=10053

drilled a 1/2" hole, screwed in my fitting with teflon tape and backed it with a nut



It worked great!!

 

back from the past....

when setting the air attachment in place, are you guys just drilling a hole, putting the fitting in and epoxy sealing it?

or are you tapping a thread into it, and screwing in the attachment?

i saw one person that had a nut on the inside of the attachment, and also used threading tape, but i havent seen anyone actually state that you tap threads into the plastic piece...?