Supercharger vs Turbo

Before all you old hands get all twisted here, I did a SOC Forum search and found some chatter about this, but most dated back a couple of years. Much of what came up was way off on other ideas. Did see a pic of a supercharger installed, however; it was off to the side vs. over the top like I thought it might go. Have always wondered (not just for these air cooled engines, but in general) why not SC vs. Turbo? Idea: No waiting for the boost, no difficult high temp seals. Aside from needing to use volume up top, seems to me these are a better deal. Never having fooled w/ such things (and I have no current plans to do so) I was wondering if there is any new technology applied to the air-cooled cars. The older comments seem to all lean toward turbo mostly because there is an established tech base: products that work, sort of, and a bunch of folks who have tried vs. any compelling technical reason. Is this just a non-starter, or is there some good recent experience out there using SC?

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Dang, that's a really big question, which is better Super or Turbo? Depends. Don't you hate that answer? This is my informal hairless monkey shade-tree mechanic info (for "qualified" answers - better get someone else!).

Superchargers are inheritantly parasitic. They draw power directly off the engine to run themselves. They make their best power at low RPM. They have ZERO "lag". They fit very nicely on "V" engines where a turbo-charger can present challenging intake/exhaust plumbing runs. I have seen them on Porsche flat 6's. But even on in-line engines, they are seen e.g. the Chevy Cobalt SS.

Turbo-charges use the expanding hot exhaust gas to power themselves. There is some restriction in the exhaust from this but the power more than makes up for it. Turbo-chargers "tend" to make their best power in the mid-range. They are often accused of "lag" but my experience with well-sorted and chosen turbos is that the lag so noticeable 20 years ago is basically gone. Turbos are easy to plumb for an in-line engine, especially one that does not have a cross-flow head (but even that is pretty easy). They spin at very high RPM and can be subject to "coking" from hot oil that passes thru the bearings on shut-down. The oil can turn into burned on tar which will hugely shorten the turbo life. I have seen after-oilers that continue to circulate oil thru the turbo bearings for a couple of minutes after shut-down.

Here's my shade-tree mechanic bottom line. Either system if chosen properly and of good quality for your application can make terrific power. You need to see what is available, determine packaging and total cost. That said, for smaller displacement engines, there are more turbo systems available than superchargers.
angela