turbo or supercharge ?

[deliriousga]

Originally Posted by MNBoxster

It's efficiency drops off rather quickly. Another disadvantage to the Super is the Parasitic Loss since it draws Crank HP. In the case of the Jag XK8, at full spool up the Supercharger is drawing 86 Crank HP , there's still a considerable 100 HP Net gain though and the Super has little Lag.

Good point about losing the crank power. I didn't think about that. Either one would be a PITA to try and install in the Boxster because of the engine and exhaust location and no open space at all.

Originally Posted by Pilot2519j

Regardless both are extravagant in cost that make absolutedly no sense financially.

Amen! For the price, you can almost get a new, bigger NA engine (or car in some cases). I looked into it for the 928 since several have supercharged theirs and raised it to 550+ RWHP. The SC kit's over $7K while a new engine is around $5K (not to mention I only $10K for the car). Add the other stuff you need to do it right (new fuel lines, pressure regulators, etc., etc.) and labor if you can't DIY and it gets nuts. The turbo kit's a little less $$, but nobody on the 928 forum has figured out where to put it yet.

While an additional 230HP would be fun, the risks of screwing everything up are too great. I can't tell you how many people have ended up with a burning car because the old (over 5 years) fuel lines could not handle the new pressure, burst and gas flew all over the engine. Poof!

If you want something that can practically fly, you can get a factory SC'ed Mustang, Jag, etc. and go really, really fast down the highway, but I'll wave bye-bye when we exit and you can't hold the road.

NASCAR or Formula 1 , it's a matter of your taste/preference and available $$.

[BuffaloBoxster]

I think you're playing with fire by trying to squeeze large amounts of power from a motor through forced-induction bolt-ons. Have a look at engines built for forced induction and they generally have lower compression ratios, stronger connecting rods, beefed up cooling systems...

You can't just force more air and fuel into the motor without thinking about lots of other things.

[chiefsalami]

I'll just add my 2 cents. I've owned and driven both turbo'd and supercharged cars. Actually, I have a supercharged VW R32 right now that I'm selling because of having replaced it with the Box. But I digress...

Tubos are nice, can often make more power by not robbing power off the crank, but there was a very good point made about the turbo kicking in, perhaps at inopertune times. Superchargers give the feel of a NA car, because they are always making some power, and make more as the revs increase. My R32 feels just like a stock one, only with more power. No wheel hop or breaking free like my previous turbo GTI did. Granted, it was front-wheel drive, but the same effects can be had with rear wheel drive, where losing grip because of turbo spool-up can cause a spinout and a disaster.

Now, as far as requiring modified internals for a supercharger, it's not true in general. My R32 supercharger kit is a straight bolt-on with no internal modifications, including to gaskets. However, this depends on the car. VW's engine is very robust, with no complaints of weak seals and leaks. Porsche, on the other hand, is a different animal. So although you could certainly push more power out of this engine (it's certainly capable - 250 or so is pretty low for a 3.2L six), perhaps it's not the best idea without really doing it right and improving some of the other known shortcomings.

It's all a matter of weighing cost (or potential cost when things go wrong) versus benefit. Of course, throw any remaining warranty out the window when you upgrade in this manner, and these cars and engines are hard enough to access/work on already.