Let me try to set this up so it does not come off as arguing for argument sakes, I'm of the opinion that any time you use a power adder of any sort your adding stress into the motor by artifiscially (SP?) inducing more power than the motor will make normally. As far as HP per C.I. you can make a very small C.I. motor make a lot of power with enough compression and RPM, you can make a much larger C.I. motor make the same HP at a much lower RPM with a lot less strees on the components due to the lower RPM. As far as adding boost and reducing timing your reducing the timing the stay out of detonation, the inside combustion chamber temps. are much higher with the added pressure of the boost and will detonate a lot sooner than having the pressures less, hence you retard the timing to stop detonation. The blown Hemi mtor I referrenced like 33 degrees total timing with 7 lbs of boost at 12 % underdriven on CA pump swill, I had tried 28 to 35 degrees and it like 33. We switched the fuel to C16 and reverse the pulleys so the motor would overdrive the blower 13%, I reset the timing to 25 degrees and made a pull. The motor made peak HP (1027 HP) at 6500 RPM with that timing and 12lbs of boost, but is was on the edge of detonation and stop gaining power at 6500 I reset the timing up 2 derees to 27 and the motor started into detonation at 6200 RPM so we stop the pulls at that time. Maximum effeincy can be tuned for any combination, large C.I. and slow RPM will make a lot more torque than a smaller motor making the same HP at a higher RPM, especially with boost Is that chart you link to for a small europen deisel motor, Otto cycle? If so you and I both know that diesel motors that self ignite have to have stronger cranks, rods, pistons and blocks to make them live at the same power levels as a gas motor makes, correct? If it isn't for a deisel motor forgive me for seeing and thinking of Dr. Otto Deisel, or Dr. Deisel Otto (which ever his name was ) the inventor of diesel motors and theory. My last pump gas street stroker motor in my Duster made 727 HP at 6700 RPM and 540 ft. lbs at 3500 RPM and had 735 FT lbs at 4500 RPM. It was a blast to drive and did require some maintenance on the valve springs do to using a moderate solid roller cam on the street, if I had added a blower to a smaller C.I. motor to make the same HP I'm sure it would have required more maintenance and better parts to live at that power level Lots of ways out there to have fun