Date:         Sat, 28 Jul 2007 08:05:25 -0700
Reply-To:     Don Hanson <dhanson@GORGE.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Don Hanson <dhanson@GORGE.NET>
Subject:      Power output of actual vans? (long)
Content-Type: text/plain; charset="Windows-1252"

Has anyone actually documented the output of the various engine combos in
vans?  I ask this with a LOT of experience with boasting car owners,
optimistic aftermarket parts vendors, erroneous factory HP figures, etc.
While involved in racing with the Porsche brand, HP was an often exaggerated
and misrepresented figure, sometimes stated as 'at the crank' sometimes "at
the wheels" and with all kinds of different  'correction factors' inserted
before the bottom line.  The same motor  in the same chassis would produce
varied numbers on different brand dynos, also.
  So, when we hear figures for all these motor/combos, what, exactly are we
hearing?  Where do the numbers come from?  If someone simply quotes what the
factory said the power  figures were, for a particular type motor, brand
new,  it may not have much relation to 'that motor' in the van..
  For instance, Porsche, in it's sales verbiage in the '80s,  understated
the HP of the 928 motor by a significant amount. Said  to  have been done
because 911 at that time was the company's designated high performance model
and they didn't want to confuse their Base, 'The Faithful'   (911s are the
only "real" Porsche)   by offering a Porsche with more acknowledged hp than
the 911.  And the Dodge Viper's hype gave HP output figures in the 450 hp
range, but they figured it at the crank, not at the wheels..
  So when someone says.."Ha, the X-type conversion motor has 150hp (or
whatever), while the WBX is only 90 or some such, it'd be interesting to
hear where those numbers are coming from.
  Aftermarket 'speed-parts'...First thing done on a racecar during engine
development is to do a 'baseline' dyno run, so you can  see if what you
modify actually does increase power..My 90GT Porsche 928 motor started life
with some 285hp (on a Dynojet chassis dyno at sea level) and ended up (so
far) with 587 on the same dyno.  But during development, many bulls--t
avenues were followed and proven to be no gain or even a hp loss, again
verified on the dyno.  "Seat-O-Pants" impressions are often mistaken, too.
I made modifications that I would have sworn felt like 20-50 more hp, but
sometimes were just noise and wishful thinking, when verified at the dyno,
or with laptimes at a known track.
  Dyno sessions aren't too expensive or difficult to complete, especially
since the 'tuner car' market has developed.  There are dyno shops around in
most larger metropolitan  areas where you can get onto the roller for a half
hour and get actual data for a nominal fee.
  I'd love to see the curves for the various types of conversion motors, to
actually compare  It's too easy to just 'say'.stuff about how a particular
motor works..but the figures would be less subjective, if we had some.
  Don Hanson