The examples everyone has given serve to make my point. [Thank you to everyone who has posted on this thread, btw]
There are two ways to make more boost.
1: Make more heat energy.
1a: This can happen by mashing the go peddle harder... or
1b: By turning up the IP, which gives more fuel, to make more heat energy [same end result, just comes on sooner in the RPM range]
or
2: Move the heat energy from the combustion chamber to the turbine wheel more efficiently with less turbulence and fluid flow loss [air is a fluid, in engineering terms].
In both 1: and 2: the efficiency of the cold side [compressor] flow also must be balanced against the work energy produced by the hot side [turbine wheel].
The 30 yr old designs presently running on IDI's are less efficient, have greater losses, and produce less work energy per BTU of heat energy than more modern turbocharger system designs. Which is my point.
If intake manifold and exhaust manifold design were matched to a properly sized turbine, I believe we could easily see 25 lbs of boost at mid throttle range, based on total airflow through a 7.3. That other engine with 6 in a row pushes those kinds of numbers, imagine what a 7.3 would do with reliable 20 lbs of boost?
If you are pushing enough air into a Diesel engine, it shouldn't "roll coal", it should just make more power. If you are blowing black, it's unburned fuel out the stack from trying to make more heat energy by adding more fuel rather than more oxygen for more complete combustion.
Anyone have access to a CNC water jet to make a set of plates to build intake and exhaust?
I would like to see a complete turbo/exhaust/intake match in a nice tight system that doesn't sell for huge bucks. I think R & D folks are on the right track.. just haven't done a very scientific execution ... yet...
