[s-cars] re: RS2 turbo crosspost GP

[Robert Mangas]

FWIW re: the Garrett ball bearing units-

  There's a pretty good sized user base in the Miata community; FlyinMiata 
have been selling one or another of the Garrett BB turbos for going on 4 
years now and I've only heard of 2 or 3 failures (there may have been more, 
but certainly some were abuse situations like crap in the oil resulting from 
shedding a bearing.)  I've about 55k on mine and no troubles at all.

   There are two caveats that I know of.  The first is that the bb units are 
not easily rebuilt; the balancing of the rotating assembly requires some 
sort of elfin magic not normall available.  Contrast this to the sleeve 
bearing units which can be done with a parts kit on your kitchen table, last 
I knew you had to essentially buy a new center section right from Garrett.  
The other is more elusive- a bb turbo will have higher rotational inertia 
than a sleeve bearing unit with the same wheels because the balls contribute 
to the rotating mass.  The distribution of this mass is further out from the 
axis of rotation as well.  If you could run back to back comparisons you 
might find that the sleeve bearing types respond to pedal angle changes a 
little more quickly.

$0.03,
Robert

>From: <auditude at cox.net>

>
>I've heard of failures with ball bearing turbos as well as Garrett/3K 
>hybrids (in general), so I've been holding back on wanting one of those.  I 
>haven't heard what killed them tho'.  If the GT series newer and different 
>than those that failed, and not to mention it's not a hybrid, maybe that's 
>old thinking.

_________________________________________________________________
Check out the new MSN 9 Dial-up — fast & reliable Internet access with prime 
features! http://join.msn.com/?pgmarket=en-us&page=dialup/home&ST=1