This snap (i.e the part about less frictional losses for the bottom-end): code words for narrower, possibly smaller dia. bearings... less capable of taking loads.After having spent so much time focused &researching this engine/transmission, feeling how it responds with the supercharger, I am convinced this engine could take significantly more boost!
I need to make some video of driving around with the boost gauge visible, it's so gentle and seemless I honestly think I'll get 200k miles out of this car, it's at 42k now (we'll see how long the bearings in the supercharger last). Because of the supercharger I'm not revving as high rpm or shifting as much, so that in some way offsets the negative of higher pressures during combustion...
specifically, below 4000 rpm peak boost is 4-5psi (which can hit even at 1400rpm) and up above 5000 rpm it'll hit 6psi with a touch of 7psi up at red-line. So it's really not a lot of boost pressure, but it's FLOWING a lot more air, according to MazdaEdit it went up 42% (150m/s to 216m/s), by mass airflow sensor, at red-line!
Now 'what is the limit' is a question nobody wants to find out for sure, but Corksport assures me they are releasing their turbo kit next month and it will be significantly more power than my supercharger and that it makes it faster than a speed3, so I'm guessing 10-12psi, but until they release details I'm just guessing. I think at that level it's gotta to be shortening the life of the engine and/or transmission.
For reference I thought this page was interesting Mazda 2.5 SkyActiv-G Engine
"All internal components are lighter and stronger now. There is a forged steel crankshaft, forged connecting rods, and aluminum pistons. The friction of the bottom end was reduced by 30 percent."
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