Does anyone know the size hole they drill in the boost elbow? It like like it would be very eary just to drill a hole in the stock elbow or stick a pin into the rubber hose? I am sure I could make one with fittings pretty easy, but drilling a hole would be alot cheaper than a pile of brass.

 

Put a tee in the line and put a needle valve on the open end. Keep opening it till you get the boost you want. You could run the line inside and have adjustment on the go to get the boost where you want it and then move it.

 

I drilled and tapped a regular npt male to hose barb elbow, to accept a 1/4" set screw.

Yup, that's it.

Used teflon pipe sealant on the screw threads to make sure it doesn't move.

 

Is it a 1/8" barb? I forgot to look when I was checking it out.

 

You need the bleed orifice or its only a boost delay. Just the restriction and no bleed orifice WON'T work..

 

Actually, it will still work. The hole just needs to be slightly larger. I have built many of 'em over the years.

Dave

 

I was wondering about this as well being that pressure is pressure and cutting off the flow is just adjusting the volume. But maybe this works with the WG as it might need a volume of at 20psi to push it open.

 

Exactly. A boost elbow is a pressure regulator. The bleed down stream of the restriction is required to keep the pressure differential from upstream.

This was a good thread on it..https://www.dieseltruckresource.com/...ht=Boost+elbow

 

All i can say for sure, is with this primitive setup in mine, I can get 30psi at the manifold, so I suppose it works.

I don't have it shut right off though, just mostly.

 

from looking t your mods they are fairly similar to mine. i also toyed with the idea of making an elbow or controller of some type. instead, i just removed the stock elbow and replaced it with a pipe plug and that has worked just fine. i can only take it to about 31lbs with what you see in sig.

 

The biggest problem with not having a bleed between the elbow/valve and the wastegate actuator is that when you are on it hard and the wastegate opens, and then you let off, the air in the actuator has to go somewhere. If it has to go back through the restriction, then the wastegate will shut slowly.

So if you were getting on it hard, then let off for a second, and immediately stomped it again, the wastegate actuator may still be open so it will spool slower. With a bleed hole, the actuator can go back to being closed as soon as you get under the set boost level since the air in the actuator can just vent to outside.

Eric

 

That's what I did too. In the end it looks just like the TST one.

 

Without the bleed its just a wastegate delay.

When you are towing on a long hard pull eventually the wastegate will open at the OEM pressure of 23-25 psi and stay open even under your "set point" of 3x Psi. EGTS will stay high, when you lug down the rpm boost will fall dramatically faster as the WG is stuck open. If you had the bleed, then as soon as you are below your opening pressure your WG will close and you can maintain higher boost.

You need the bleed for it work properly.

 

I wish I had some pictures of the ones I've made up.

But I start out with a 1/8" pipe thread street T with the 2 female thread and the male thread on the run. I find a ball bearing that is big enough to seat in the bottom of the T without danger of falling through or out. I put a barb fitting in the bull of the T with a small bleed hole drilled in it.

In the thread opposite the male I put sutiable spring and a pipe plug I modify by drilling and tapping for 1/4-20 threads. I machine the end of the threaded rod so it will hold the spring properly and you can adjust the springs pressure on the ball so it will lift off the seat at the same pressure every time.