RE: Supercharged vs. Turbo

["Crane, Damien" <d3c@TENNANTCO.com>]

I too am familiar with this book, and also think it is great.  However, I
don't agree with the authors opinion in the turbo vs super debate.  Remember
that this book was written a long time ago, and turbos have come a long way.
One look at the torque curve of the new 1AT engine (Audi 1.8 Turbo) compared
to the Corrado G60 shows that low speed torque does not have to be a
problem.  I have spent a lot of time driving a newer Saab 2.3 liter 16v
turbo.  The lag was really non existant.  It felt like a 4 Liter engine.
This really surprised me as I used to have a 900T with an 8 valve turbo
(CIS).  Lag was bad.  It was annoying as hell to drive in town.  The newer
engine/management/turbo combination completely transformed the feel of the
newer car.  At one point I put 3000 miles on the car in a week driving to
and in the mountains.  Averaged 29mpg overall and over 80mph on the freeway
trips (1000 miles each way).  It convinced me that turbos can be a very good
thing.  Torque for the Saab was 258lb ft at 1900 rpm.  Audi and Volvo have
similar.  I really, really _really_ hope the A4 golf can be had with the 1.8
Turbo in this country.

Damien

> ----------
> From: 	Tim Ebling[SMTP:tim@surreal.com]
> Sent: 	Monday, October 19, 1998 2:52 PM
> To: 	'Scirocco Mail List'
> Subject: 	Supercharged vs. Turbo
> 
> 
> Ok I know this is a debate that rages EVERYWHERE, but I thought it'd be
> relevant to bring it up now with the talk about 16V turbos.
> 
> At the Oktobugfest show yesterday (Puyallup, WA), I was fortunate enough
> to
> pick up Greg Raven's "Watercooled Performance Handbook", which someone
> mentioned was out of print.  What a great book!  This guy seems to really
> know engines, not just from a practical standpoint, but from a theoretical
> and scientific standpoint as well.  Bottom line is, I was impressed with
> his
> knowledge.
> 
> Anyway, a chapter in the book is devoted to turbos and superchargers for
> VW
> engines up to 1989.  After reading this chapter, it was quite clear that
> he
> favored the supercharger to the turbo.  In fact, he states "Superchargers
> are inherently better then a turbo for a street-driven gasoline engine"
> (p.
> 108).  The main advantage he pointed out for the supercharger was its
> ability to provide equal boost throughout the RPM range, as opposed to the
> turbo which has to rely on a wastegate system to provide this equalization
> (and hence is not as efficient).  There's also the issue of turbo lag
> (spin-up time), which is nonexistent for the charger.  In fact, the only
> advantage he cites for the turbo is its ability to perform at high
> altitudes.
> 
> Anyway, I realize this is one man's opinion (albeit an educated one it
> seems), and I'm sure there are plenty of turbo evangelists out there (on
> this list I'd imagine), but it does make me think.
> 
> So let the debate begin!  What do the folks with turbos or are doing turbo
> conversions think?  Is it simply a matter of the parts for chargers not
> being available?  I'm also concerned about the longevity factor of a
> turbo.
> Superchargers seem to be more reliable, which is why VW chose to put a
> G-lader on the Corrado instead of a turbo (which they did experiment
> with)...
> 
> -tim
> 
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