I ran a search and didn't find anything definative. I want to know what the options are for reading boost pressure. I've got the gauges now and will be installing shortly. My preferance is to see what the engine is getting post after-cooler. I know that some guys are seeing wastegate pressure by teeing in that line, but I'm not certain that is the most accurate.


Comments?http://www.dieselplace.com/forum/smileys/Approve.gif

They both are only as accurate as the gauge reading the pressure. Reading pressure represents as you stated the following:


(a) Tee at wastegate indicates boost pressure from compressor before the IC. This is good at determining the pressure ratio when reading the compressor Map to compare with the mass air flow (#/min). The pressure reading at this point is the best indicator of the compressor performance.


(b) After the intercooler indicates the pressure entering the intake manifold. The difference between the two readings (so long as gauges read the same) is the boost drop from the IC. The pressure reading at this point is the best used to see if you have any boost spikes or drops feeding the intake. This is not a direct indication as to what the pressure in the intake port is. This would require a pressure reading at the flange of the intake manifold and head.


FYI


The stock IHI compressor (assuming Standard Temperature and Pressure, STP).


IHI RHG6
<DIR>


P/R of 2.6, [Boost 22 psig (STP) before IC], Max flow 55#/min [110,000 rpm], limited at 70% eff, Surge Line @30#/min (includes MWE)


P/R of 2.8, [Boost 25 psig (STP) before IC], Max flow 52#/min [limited at 110,000 rpm], eff 74%, Surge Line @33#/min (includes MWE)


P/R of 3.0, [Boost 28 psig (STP) before IC], [off of compressor map]


Deep Enough


Donald McMullin</DIR>