Vince99FRC

My buddy has a setup to test for boost leaks on my single turbo Supra, but he reports it will not work on my twin turbo Vette. How do you guys do it? In the past I did a visual inspection and the leaks were obvious. One time I could actually hear the leak on the dyno and it was clear where it was coming from. This time I cant seem to find it, but I know there is one because there is no change when I turn the boost controller off or up the boost. The slow boost response is the same. All good suggestions are welcome.

1%r

Buy a smoke machine.

Used one on all the all the Supra's we used to build.

Vince99FRC

I guess somehow I could seal it off near the TB and ignore the smoke coming from the filters.

Vince99FRC

Actually I just thought about it. I think my leak comes about when the system is pressurized. Unless the leak is all the time the smoke idea wont work. I guess I will try to just block off the other turbo so the air wont get out when we pressurize the other side of the system.

longdrive70

Why not block off the pipes (high pressure) on both sides just after the turbo and then pressurize the system at the airbridge (disconnect from throttle body). In a past setup, I used 4" PCV rubber plugs tapped with a fitting to pressurize the system.

Vince99FRC

Thats a good idea. If I do that I could use my buddies device to pressurize the system with a few modifications to his.. His is exactly like this one.. I need to see if his hose will fit over the top of the intercooler pipe post the maf connection..

Contributed by Virus77
This is something that is pretty handy and costs a few bucks, eveyone should make one.

Yours will look different but will do the same thing.



Parts you need:

-The coupler you use to connect your intake pipe/mafs to your compressor intake.
-a pvc end cap from home depot that fits snugly into your coupler. (so its the same size as your compressor inlet on your turbo)
-simple hose clamps to hold things together.
-some form of air compressor (personal, shop compressor, foot pump, etc...) Further testing showed you need a pretty decent pump to make this effective, shop pump or home air compressor would be best
-a fitting to attach your air compressor of choice to pvc endcap (refer to pictures)

Here are the pics:

The end cap needs to have a hold drilled in it so your fitting can attach to it. This is where you will presurize the system from.



you insert the end cap into your silicon/rubber coupler and clamp it down (I had that extra silicone bend for my new maf piping I was gonna make so im using that for the time being)

The other side of the contraption gets attached to your turbos compressor intake (where the air filter/mafs coupler would normally go).

if you have a bottom mount setup and its difficult to get to the turbos intake you can also pressurize the system from after the mafs and use your cars intake piping as an extension to the turbos intake. However when doing this make sure the any line going to the intake are plugged. For instance if you have a valve cover breather line/ PCV / catch tank going to the intake pipe it needs to be plugged or else you are going to pressurize your valvecover, crankcase, etc and it wont work. Although I did find a valve cover gasket leak like this




Then you attach your choice of air compressor to the fitting on the end cap side and you pressurize the system. Check your boost guage and presurize the system up to like 15 psi or whatever you would run to see if anything pops off.

Final product



Thats pretty much it. Obviously the motor is off while you do this so If you have the slightest leak it will make a loud noise and you will find it, also if your intercooler connections are leaking it will leak and you will find those aswell. Depending on the size of your leaks you might not be even to pressurize over a few psi, so just keep fixing leaks till you hear no noise.

AlwaysInBoost

you should be able to do a pressure test w/o removing anything but the intake(s) on both compressor inlets. This is also be called the COLD side piping.

Since its twins you'll have to CAP off one turbo so no air can get in or out, depending on your inlet size you can get some FERNCO couplers @ home depot and PVC caps, that should do the trick.

Then you will need to pressurize the other turbo inlet and listen for leaks. If you are running an MBC, make sure you close it before, otherwise it will bleed all your pressure off. Just remember how many times you turned it so you can reset your boost back to where it was.

The most important thing however is to NOT remove any of your charge piping while doing this test, only the intake piping from the cold side of the turbo, otherwise it would totally defeat the purpose of testing for leaks in the first place.

Warp Factor

It might be tricky to position the engine so no cylinders are on valve overlap.

AlwaysInBoost

I know what you are saying, but I've done this test dozens of times on quite a few different types of vehicles and its never been a problem on any of them.

Vince99FRC

Real good information......

Vince99FRC

I found the boost leak. I did not have to perform any test. LOL!!

I replaced several hoses and my new hose popped off the turbo. It was letting air pass under pressure, but came off completely within the past couple of days. You are looking at the driver side turbo compressor outlet hose going toward the intercooler. It is completely off.

NICK YOSKIN

u using worm clamps?
if so go to NAPA and get some t bolts
BTW get those new JZ compressor wheels man!

Vince99FRC

Yes the kit comes with worm clamps. I am going with t bolt clamps. I have some. I wont be able to do it until my next day off..

Those JZ turbos are tempting.. 1300 a pop though. Can I first max out my current ones?

NICK YOSKIN

NO

Vince99FRC

You are the type of guy that would purchase a 15000sqft home and live in it by yourself.

Why should I change turbos when we all know C5 drivetrains are suspect? Why should I change turbos when I have YET to fully use the ones I have? Why should I change turbos when I dont even go to the track? Why spend another 2600 in turbos I dont need?

Vince99FRC

This was the old hose on the car. There was a huge hole in it.

Vince99FRC

Finally had time to repair the boost leak. The hose is back on and as usual the car wakes the HELL UP!!

0EG@EnglandGreen

zbc51

deja vu, I had a similar problem last summer. I had a boost leak that sounded like a horn blowing when I was under boost. Eventually the same hose failed on my car; but it was from it rubbing on the front sub frame. I could'nt get my big fat hand in there to replace it. Phil fixed it in about 30 minutes; no problems since then.

Vince99FRC

People were saying my car was loud as hell!! You are lucky to have Phil near you. He knows this kit like the back of his hand. My hands were not designed to work on this kit. Everytime I work on something I have to ask my buddy TJ or Sam for the use of their small hands. When there is no boost leak the car is just plain SICK!!