Post by
Wulfgang »
https://forums.nicoclub.com/wulfgang-u10889.html
Tue Oct 04, 2005 7:37 am
Supers have their place, but IMHO it would be hard to justify supercharging an RB (unless you just want to say "I did it" like the guys that built that insane setup above).
The big advantage of superchargers is that they can provide excellent throttle response due to their operation and often also due to their installation (right on top of the intake valves). IF you need to run large boost to make good power (like on a 2.0L RB20), then you must use an intercooler, which sort of defeats the purpose (unless you use an air-to-water IC which means lots of extra plumbing). Adding an IC kills throttle response no matter how well you do it.
So superchargers are prime candidates for lower boost applications, which means you can use higher compression ratios. And that is another thing counting against RB's, with their lower compression ratios.
IMHO, non-turbo engines like the KA are perfect for supercharging. They have high compression ratios and (sometimes) more displacement meaning you can run lower boost and still make big power. This enhances the chief benefit of the supercharger: throttle response.
With an RB you have an engine that was designed from the ground up to be turbocharged, and that makes it a bit of a stretch as a supercharging candidate.