Is it any wonder two cars are different on different specs by your own admission ?, ie virtually is not the same is it ?
The air standard effeciency of a 7:1 CR is 54.1 versus 56.5 for a 8:1, and you can notice this, have you not stopped to think that therreason you can feel something is because the lower cr one was running more boost, as this is what "old school" used to do ?
As I did not use the word ELIMINATE, what is your point ?
A sleeve bearing(normal type) has a typical bearing loss of 800 WATTS, ie it takes 800 WATTS of energy just to rotate it.
A ROLLER BEARING one takes 200 WATTS.
The shaft movement at 150,000rpm is typically 0.025mm for the SLEEVE BEARING versus 0.13-0.25mm for the ROLLER BEARING.
The FLOATING(SLEEVE) bearings DO NOT ROTATE AT SLOW SPEED at all, but the ROLLER NEARINGS ONES DO, so VIRTUALLY ZERO LAG.
When NISSAN did some testing with traditional SLEEVE bearings versus the ROLLER bearings the results were, time to boost to 40Kpa 5.3 seconds on the standard bearing as opposed to 1.6 seconds on the ROLLER bearing, so a clear improvement might be what some would consider this!!
The ONLY reason lower CR went out is to do with EMISSIONS ,a nd nothing else, the lower the CR the dirtier it is.
VARIABLE VANE TURBOS still have lag, nowhere near as much, but bearing design plays a very big part, as does seal type.
tabetha