Originally Posted by lyeinyoureye
Who said anything about increases in compression and rpm range? Granted, the
EPA test used a TDI engine, but that's only because it's the only stock/cheap engine with a VNT and EGR cooler iirc. So, when running high rates of EGR, they didn't have to make many modifications to the engine, only run SAFI (Stand Alone Fuel Injection). The point of the paper was that higher octane fuels allow for more EGR, which fills up the cylinder and minimizes low load pumping losses. This can be done with lower compression engines, all that's needed is turbocharging/EGR cooling. The same system was mentioned in a Uni of Wisconsin paper. In fact, the engine would probably last longer because it's more efficient. It won't have to inject extra gas just to overcome the pressure difference between the cylinder and crankcase on the intake stroke.
Hardly. If this were the case we wouldn't have drive by wire, VVT-whatever, or anything else. The only thing needed for this would be a turbocharger, EGR cooler, and associated hardware. I bet a reasonable approximation could be done w/o turbocharging via internal EGR.
any significant gains in efficiency, and I mean real significant gains taking advantage of the octane levels of ethanol mean increases in compression, and better machining to increase the volumetric efficiency, which in trun means more power per cubic inch
there are NO MAGIC BULLETS HERE, engine tech is a very very mature well known discipline, one Im familiar with
turbocharging in effect increases the dynamic compression in the cylinders, this is also well known and understood, typically turbo'd engines run very very low compression, reason being cylinder filling with a dense charge raises the effective compression ratio, they also suffer all the things that go with it, like short lifespans
your not gonna BS your way out of this one