RE; 3/90 COUPE QUATTRO CHANGES

[Porsray@aol.com]

(THIS IS A COMPLETION OF MY FRIDAY E-MAIL; KEEP FORGETTING CAN'T USE
TABS WHEN COMPOSING MAIL ON AMERICA ON-LINE)!

Regarding changes with the March 1990 Coupe production date, I believe they
are:
     -    Exhaust manifold/header changed from stainless steel to cast iron
          (I believe the concensus is the stainless steel is better for
performance)
     -    Changed O2 sensor location due to above
     -    Revised MFI "brain box" (could read trouble codes on old one with a
          little box with some Radio Shack parts; new one requires expensive
          diagnostic tool).
          Don't know if functionally anything changed.
     -    Front sway bar mount was changed sometime in 1990 model year; don't
          know if was in conjunction with above
     -    Manual says that "all model year 1990 80/90s had airbag".  Don't
          think this is true; my Coupe is a '90 built in July '89, has no
airbag.  
          Do not know when change was made.
     -    Revised hydraulic components (pump, accumulator, lines, etc.)
          Manual says done after serial no. 8B-LA006861, which was after Oct.
'89
     -    Power steering rack (done after 8B-MA002645; approx. Aug. '90)

As far as which is best, my feeling is that changes were made to correct
problems with old ones (I feel this is especially true with hydraulic
system). 
Old stainless steel header ir probably better than newre one, but probably
not to any extent where  you would feel it by the seat of your pants.


Ray Calvo
porsray@aol.com

1990 Coupe Quattro  (105,000 miles)
1995 Porsche 993 Coupe