On Sun, 21 Jun 2015 23:39:10 -0400, Ed Huntress
wrote:

On Mon, 22 Jun 2015 08:30:31 +0700, John B.
wrote:

On Sun, 21 Jun 2015 17:40:11 -0400, Ed Huntress
wrote:

For the gearheads:

If you think that engines are getting too complicated, you'll want to
take a look at Volvo's T6 engine. It has both a mechanical
supercharger and a turbocharger.

This has been in the press for around a year, but the engine is
available in two cars, is in production, and is getting some reviews.
Apparently it's very nice to drive. I wonder how nice it is to
repair...

The Eaton supercharger is there for low-end boost, to make the 2-liter
4-cyl. feel like a V8, with no turbo lag. At around 3500 rpm, a clutch
disingages the supercharger and the turbo, which is now fully spooled
up, takes over. It produces 302 hp and 295 ft.-lb of torque.

It's impressive engineering but I think they just tipped over the
edge. With direct injection, variable cam timing, and two types of
superchargers, it has to make mechanics gulp. I hope they've given as
much thought to maintenance and repair.

The Detroit Diesel engine had both roots blower and turbo, in some
instances. And yes, I know what it as for but the roots "blower" did
give an intake pressure higher than atmospheric, thus was a
"supercharger" by definition :-)

Pfhhht. g


And didn't VW market a car that had this system? Called the GT TSI, or
some such name. Back in 2005, or thereabouts.

Ohhhh, yeah. That one disappeared in a hurry, didn't it? I had
forgotten all about that one.


Add variable valve timing (which is old hat now-a-days_) and Viola! A
NEW Design :-)

I'd like to drive one, just to see how it feels.

Sometimes the "cutting edge" cuts both ways :-)

I had a friend that bought one of the first Wankel engine Mazda cars
imported into Thailand..... A year later he replaced the rotary with a
piston engine :-) He told me that he had it done at the Mazda shop and
it was literally a "drop in". Although that was likely an
engine-transmission package drop in.

(Years later he died of alcoholism but I'm not sure if the Mazda or
the woman he married caused that :-)
--
cheers,

John B.