home *** CD-ROM | disk | FTP | other *** search
- Path: sparky!uunet!ogicse!uwm.edu!zaphod.mps.ohio-state.edu!cs.utexas.edu!lgc.com!jlg
- From: jlg@zycor.lgc.com
- Newsgroups: rec.autos
- Subject: Re: Formula (was Re: BETTER? 92 Camaro...)
- Message-ID: <1992Nov11.210322.20230@lgc.com>
- Date: 11 Nov 92 21:03:22 GMT
- Article-I.D.: lgc.1992Nov11.210322.20230
- Sender: usenet@lgc.com
- Distribution: na
- Organization: Landmark/Zycor (Austin TX)
- Lines: 82
- Originator: jlg@jason.zycor.lgc.com
- Nntp-Posting-Host: jason.zycor.lgc.com
-
- > I think the cheesy rear-end had problems with the jolts
- >associated with manual shifting under the extra torque, as well.
- >The 1LE cars got the aussie-built 7.75" unit.
- >
- >>
- >>> Also, the 4 wheel disc's were standard on any Firebird with a TPI
- >>>engine (5.0L or 5.7L). It looks like in '89 they started putting
- >>>bigger discs on the rear, along with dual exhaust past the cat's.
- >>>It was good for another 10 hp.
- >>
- >>On my build sheet rear discs are an option.
- >>
- >>Hmmm. I have seen some TPI examples with (ugh) rear drums, but this is
- >>Canada. What year is your Pontiac catalog for? I thought the dual cats
- >>were standard on the GTA and optional on TPI FORMULAS & T/A's
- >
- > The firebird literature in (88-90? memory fade) claimed that
- >the 4 wheel disks were a required option on the TPI 'birds. It
- >also said that 5.0 TPI 5 speeds and 5.7 cars got the dual cats.
- >I seem to recollect a recall on TA's or GTA's that didn't get the
- >dual cats....they were re-fitted with the proper setup.
- >
- > Despite what the literature says, I've seen (usually late
- >in the model year) TPI firebirds with the rear drums. But the scariest
- >thing I saw was a 5.7 IROC with rear drums and 15", non-speed rated
- >GT +4's! A car that would go 145 MPH with tires that go to mush
- >at 120....hope that thing had a speed limiter...
- >
- > Just for laughs, what axle ratios do your cars have, and
- >what are the 'G' codes on your option sticker?
- >
- >--Ken
-
-
- 1LE f-bodies are not the only f-bodies to have the Borg-Warner 'australian',
- 9 bolt rear end. All '87-'89 5.7 IROC's and all '87-'89 5.0 G92 5 speed IROC's
- have the BW rear end. WS6 Firebirds went the BW rear end one year earlier (1986).
- 1989 was the last year for any BW f-body rear end.
-
- In addition, all 5.7 IROC's ('87-'90) and 5.7 Z28's ('91-'92) required rear disc
- brakes and the 16 inch wheels. The same was true for all 5.0 TPI G92 5 speed
- IROC's ('87-'90) and all 5.0 TPI G92 Z28's ('91-'92).
-
- The only TPI powered f-bodies (a lot of them) that have rear drums are 5.0 non-G92
- automatics and 5.0 non-G92 5 speeds.
-
- The 5.7 IROC you saw with rear drums and 15 inch wheels was likely not a 5.7.
- I have seen several 5.0 IROC's rebadged as 5.7 IROC's. To be sure, always
- check the VIN:
-
- Engine codes: (8th digit of VIN)
-
- H : LG4 (5.0 4bbl)
- 7 : LU5 (5.0 Cross-fire)
- E : L03 (5.0 TBI)
- G : L69 (5.0 4bbl H.O.)
- F : LB9 (5.0 TPI)
- 8 : L98 (5.7 TPI)
-
- Starting in 1989, rear disc brake equipped (J65) f-bodies got larger 11.65 rotors
- replacing the previous 10.5 rotors. The front discs remained 10.5 rotors. The
- 1LE package however would replace the front 10.5 rotors with 11.86 rotors.
-
- The first dual-cat (N10) equipped f-bodies were available in 1989; ordering the
- G92 option (performance axle ratio) determined whether dual cats N10 were installed.
- In 1989, both 5.0 and 5.7 TPI could be had with or without the G92 option so you
- will see 1989 5.0 and 5.7 TPI f-bodies with or without the dual cats. The situation
- changed for '90-'92 when only one axle ratio was available with the 5.7: 3.23 non-
- BW. All these 5.7 cars are G92 and have the dual cats.
-
- If interested, join the f-body mailing list (f-body-request@boogie.ebay.sun.com)
- where such topics are discussed regularly.
-
-
- John Gravell
-
-
- --
- Yr Model Engine Displacement HP Torque Induction
- ---------------------------------------------------------------------
- 85 IROC-Z (man.) L69 5.0 (305) 190 240 4BBL H.O.
- 87 IROC-Z (man.) LB9 5.0 (305) 215 295 TPI
-