Stock Boost on ALH 1.9L

IndigoBlueWagon said:

Not sure what you're reading, but keep in mind that some boost readings are atmosphere plus requested boost. If that's the case, 37.2 would actually be 37.2 less 15.7 or so, or 22.2. Still too high, but if that's a spike it won't kill your turbo.

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Well that makes a lot more sense. Thanks, just trying to figure out what mods were done to this car. I suppose that explains why the wheels break lose in 3rd gear!
Thanks again

External boost gauges (Or a Scangauge with the proper Xgauge programming) will read actual pressure in the manifold - Scangauge is reading from the MAP sensor so same as what Vag-Com would show you, and the external gauge is obviously reading external to the computer. If they match, your MAP sensor is good.

Now, several years later in this thread and I still have the ALH wagon. Have upgraded some other things, new nozzles, rebuilt the injection pump which needed it badly (broken quantity adjuster spring) and have a Malone tune.

On the highway, 80mph flat road steady state cruise not towing... 4-6 psi. EGT of around 500 pre-turbo.

Thoughts? Seems that this could be higher. It only ever goes above 10 if I stuff my foot into it.

Not sure if you're asking if you expect more boost while cruising?

More boost=less fuel efficiency.

Or just more lean operation? Lean is good on a diesel, rich just makes smoke and melts pistons. If too lean, obviously power is being sacrificed b/c the cycle runs out of fuel too soon. But I would think that a bit more boost with the same fuel would be a bit better and from this thread it seems that people are getting / having more boost than I see.

There's a balance between the 2.

Melting pistons is really only happening when there is a lot of smoke. Richer than 17:1.

Running extra boost will lean it out, but not provide much in terms of safety. It will improve emissions, especially microscopic soot load, but insignificant otherwise.
The engine gets enough air to hold 80mph cleanly, without turbo boost at all; all from cylinder vacuum.
So then spinning the turbine more just robs efficiency.

Enabled said:

So then spinning the turbine more just robs efficiency.

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This. When I was running RC6 and a 17/22 Jeff set my boost up so it would be very responsive on the track. Meant I was running about 10 PSI at a 75 MPH cruise. When I stopped doing track days and he re-tuned it to RC4+ I was running 2-4 PSI at the same speed. Picked up about 4 MPG.