Boost Leak @ Boost Elbow

[BertM]

This weekend I made the adapter mentioned by Piers to check for boost leaks on the intake side. While putting pressure on, and using soapy water, I found a leak at the TST boost elbow. I sealed up the allen screw, but noticed that there is a machined hole(1/64") in the side of the elbow allowing boost loss. Is this hole there for a reason? It leaks enough that a 1. 13 CFM pump would not pressurize the system. Running, my boost is per TST specs.

 

[Steve Campbell]

My boost test revealed the same results. I see you are running the boost per TST specs (that would indicate to me that the allen screw is not fully seated in the elbow) and thus rather than changing the setting at the elbow I wound up removing the elbow and installing a temporary plug in the turbo to test the system. After the test I reinstalled the elbow back in the turbo.

 

[Fuzz]

Where?

Is there a thread on making this boost tester from Piers?

I must of missed it.

Appreciate info on where to find the how-to.

Thnks

 

[BertM]

The tester is as follows: 4"x3" fernco plumbing adapter, reduce the 3" side with 3" to 3/4" threaded pvc bushing, male/male 3/4" x3/4"x 2" nipple, 3/4"x1/2"x1/2" T, pipe pressure gauge to (1) 1/2" side, place supply air nipple in other 1/2" side(grainger has supply valves with 1/8" NPT). Pull the intake hose from the turbo, slip 4" fernco on, and pressurize to 20 psi(Slowly).

This is how I got there. I am sure there is a way eliminate some of the reducers and bushings, but I seem to always need them anyway. The fernco piece costs about $10. 00.

 

[Fuzz]

THANKS

Thanks Bert,

Off I go to Home Depot.

 

[HEMI®Dart]

Thanks Bert. I'll be making a boost tester this weekend!

 

[radixr]

Boost Leak at the elbow

I have the same leak at the elbow. It appears that this is normal. This "leak" is such a minor loss of boost that I didn't feel the need to do anything about it.



I used a 4" rubber sewer drain coupling and a 4" ABS end cap and plug to make a boost tester. I tapped the plug for an air fitting and pressure gauge. I was afraid to go past 20psi and risk bursting the rubber coupling but that is plenty to locate any leaks. I found two major leaks when I tested mine and I plan to repeat the procedure on an annual basis.

 

[R.ebel]

Boost Elbow

The leak at the boost elbow is a calibrated leak, It affects wastgate function. Plugging this calibrated leak will lower your boost by opening the wastgate sooner. That's my understanding of the Boost elbow... if I got this wrong someone please step and correct me.

 

[vc]

radixr,

can you tell us where your two major leaks were?

Also, can you post a picture of your adapter?

Thanks.

vc

 

[radixr]

vc,



My leaks were: 1. ) An intake manifold bolt had been left out after some engine work and 2. ) someone or something punched a hole in one of the intercooler tubes.



I will try to post a picture of my adapter. I will have to enlist the help of my wife -- she is the digital camera expert. I know she can attach a photo to an email; I'm not sure about posting it on the forum.

 

[Mad Bomber]

boost leek

can any one put a picture up so I can see it thanx Eric

 

[BertM]

I can post a picture, but it will be Wednesday before I can attach it to this thread. Something as ugly as this adapter looks should have a name. It has rubber, pvc, black iron, and brass.



Mark @TST said that the orifice hole is there on purpose.

 

[BertM]

Tester Picture

 

[John]

Originally posted by BertM

Mark @TST said that the orifice hole is there on purpose.

The precision bleed orifice in the TST replacement elbow (or any other manufacturers performance elbow for that matter) is there to keep from over boosting the engine. In reality this fitting is easier to install requiring almost zero mechanical ability as opposed to removing and properly readjusting the wastegate actuator (this takes time, mechanical know-how, typically a regulated air supply, and an air compressor).

 

[HEMI®Dart]

Thanks for the picture Bert. Easier to understand with a picture.

 

[radixr]

Hope this works -- Here is what my "adapter" looks like.

 

[Deezul1]

R. ebel is right, the elbow leaks boost signal so the waste gate thinks there is less boost and doesnt open as soon.

 

[Fuzz]

Made the tester but??

Hey guys I got a tester clobbered up,and when I put pressure on it ,it leaks off pretty fast.

I took out the bleed elbow and plugged the hole,for the test,but it still doesn't hold very long. On a good tight system how long does it hold pressure?

I can't hardly get around to the other side to squirt the fittings before it's gone. The device doesn't seem to be leaking.

Thanks for any input

Fuzz

 

[Snow man]

How are you guys sealing off the exhaust side of the engine? are you plugging the exhaust. There may be a cylinder that is on the valve overlap part of the cycle,it will let air in,and out past the exhaust valve and go right out the exhaust. I found my truck had a boost leak from the lower intercooler tube.

 

[radixr]

Fuzz, adjust your air inlet valve so that the leak is equal to the air coming in. Then you can take your time to locate the leak. Maybe you have the valve overlap problem that Snow man talks about. If you rotate the crankshaft a little bit, it should take care of any valve overlap condition.