Air Shrouded Injectors (and low boost)

[auditude at cox.net]

Nate Stuart <newt at newtsplace.com> wrote:
>
> If I remember correctly. the wastegate actually gets it's pressure
> reference before the throttle body, on the same line as the idle
> stabilizer.So when you drop the throttle shut the WG sees a surge in
> pressure and opens up. Though if the line was plugged as he mentioned
> before this is all a moot point.

Okay, that's much better.  This is what I originally thought, and I was going to post some about it, but then I remembered where the lower chamber hose goes to, and didn't want to post the wrong thing so I changed it.

So, what I was going to post when I hadn't convinced myself incorrectly on the WG's connection, was that without a bypass valve, you not only slow down the turbo from the buildup of pressure after the turbo from the throttle closing, but also because that buildup of pressure opens the wastegate which stops/slows the spinning of the turbo by the exhaust gases as well.  That's a lot of wasted momentum.

So, a bypass valve really helps keep the turbo spooled in more than one way, on the intake side and on the exhaust side as well.  I didn't realize this until for a short moment this morning before I thought I was wrong.  Anyway,

I think that's interesting, as prior to that I was only thinking the benefit of having a bypass valve was all based on reducing a slowdown of the turbo that was all caused by the intake side pressure spike.

Ken