Mike:
Mostly I agree with what you say below (and at most times, for that matter).
However, there is a factor that supports the "rah-rah" that Joe got from the
guy he talked to:
A turbo is such an integrated unit, that parasitic losses affect both ends:
if there is more bearing friction, the power turbine can't turn as fast for
the same mass flow/ exhaust temp. If the turbine doesn't turn as fast, the
compressor won't turn as fast, and won't pump as much air in. Less air in =
less exhaust massflow out, = less power back to the compressor-- it's a
vicious circle. So a slight difference in parasitic loss can equal a
significant difference in boost, from a given exhaust energy.
The MotoGP guys (and many of the Superbike race teams) wouldn't be going to
so much expense to convert to ball, roller, and ceramic bearings, if there
was not something to it-- even in non-turbo applications.
Russ, #1226B
-----Original Message-----
From: Flowbench@aol.com [mailto:Flowbench@aol.com]
Sent: Wednesday, October 22, 2003 1:42 PM
To: jkamo@rap.midco.net
Cc: albaugh_neil@ti.com; rtmack@concentric.net; speedtimer@charter.net;
joyseydevil@comcast.net; land-speed@autox.team.net
Subject: Re: DBB turbo's
In a message dated 10/22/03 11:23:07 AM Pacific Daylight Time,
jkamo@rap.midco.net writes:
<< and that higher boost
levels yield higher shaft speed and higher shaft speed
yields higher thrust loads, and DBB being superior at
handling axial loads make it a good choice, even for Bonneville >>
Shaft speeds at boost are the same either way, thrust does go up with high
pressures, (you still have a standard type thrust) but the rest is sales.
Still
a good unit, just not what I need.
|