What /6 is Best For Forced Induction 170, 198, or 225?

rumblefish360 said
Speaking from what i see on V8’s, a /6 isn’t going to act to differently than any other engine that is pressurized.

The cylinder head in a N/A engine will flow only so much air. A larger engine ingest more are quicker than a smaller engine. If the head can only feed a 225 to 5000 rpm, the smaller engine will be able to rev higher because of the volume of air it ingests is equal to the volume of the larger engine at a lower rpm.

All of this kind of goes out the window when your pressurized.

Not quite, the same rules apply for the same amount of rise in atmosphere provided by the compressor, a smaller engine will still RPM higher with a cylinder head of a
given flow capacity. Take the little 2.2L, the IROC R/T 4 valve head raised the RPM range of that mill by nearly 1,000 RPM at the same boost, the same would've happened
if the engine had been de-stroked to the same displacement/CFM ratio with the 2 valve head...................................................