My rooomate just picked up an 89 Formula. I couldn't find the RPO list in the car, so I've had to do this by logic.

It's a Formula, it's a 5-speed, and it has a borg-warner rear. According the the tech data on this site, that means it has the 230hp 305 LB9 right? The 220hp LB9 couldn't be had with the Borg-Warner could it?

The other thing that's weird is that I thought for the 230hp LB9 you had to have 2 cats, but his car only has 1.

Can anyone clear this up for me?

 

Lets see:
A) 220 hp single cat 305 TPI with a 5sp would have 10-bolt 3:08 rear.

B) 230 hp dual cat 305 TPI with a 5sp and G92 option would have
a BW 9-bolt 3:45 rear.

Now I would count the bolts on the rear cover to verify what make rear is under this car. The G92 option was not very common, or someone over the years replaced the exhaust system and did not want the expensive of two Cats. This may be what happened on a multi-ownered used car. My opinion.

 

I did count the bolts, definately 9. And it had Borg-Warner stamped on the bottom of it

I guess it's possible someone replaced the original exhaust. Anyone happen to have a picture of the undercarriage on a dual cat car?

 

All TTA's only had one cat and BW rear. Can't remember about the V8 cars.

 

Check the build date to see if it's an early production car. It is entirely possible to have an 89 Formula with BW rear and all the performance options but only have the single cat exhaust. N-10 (dual cats) did not make it into production until midway through the 89 model year. When I visited the Pontiac dealer in Feb 89 all the Formula 350s on the lot (10+) had single cats. I passed. When I returned in April every Formula 350 had N-10. A friend purchased an 89 Formula 350 in November 88 that came with the single cat. Although all the cars I personally saw are 350s I'm sure the story was the same with 305s.

 

To have a Formula with a 230 Hp 305 TPI & 5sp manual you needed the following for the G92 Option:
1) LB9 305 TPI engine & N10 dual cats gave the 230 HP.
2) 16" wheels & Gaterback vr tires.
3) G80 limited Slip
4) J65 rear disc brakes.
5) oil cooler
All of these options were reqiuirred for the G92 BW 9-bolt 3:45 rear.

Only with the above did you have 230 Hp & BW Rear. And very few were made with the above Set-up and had to be special ordered .

 

Point of clarification on the TGO tech data. The 230 HP rating with the LB9 is actually for the Camaro, not the Firebird. Power ratings on TPI Firebirds were typically 5 HP less than in the Camaro due to the more restrictive air intake. Here's the LB9 ratings from Pontiac's 1989 full line brochure.

LB9 w/T-5 & dual cats: 225 HP, 295 ft-lbs TQ
LB9 w/T-5 & single cat: 215 HP, 285 ft-lbs TQ
LB9 w/ auto: 190 HP, 295 ft-lbs TQ

GM rated N10 at a 10 HP and 10 ft-lbs TQ increase compared to the single cat. So, your roomates car is actually rated at 215 HP from the factory, same as in 88.

 

OK, that's good to know.

Thanks to everyone for their responses!

 

i have an 89 IROC with BW 9 bolt and a single cat. not sure if that remotely helps you or not though.

 

Is the Cat and Exhaust original & stock??????

 

i think the cat is, by the sound, the thing definitely has a new catback. what rpo would give me the dual cat and what rpo for the 9 bolt? im pretty sure this is stock, but i dont really know what was available with what options. if you know the rpos i can check for ya.

 

N10 dual cats
GW6 was the BW 9 bolt with 3.27 for the A4 cars

My car was buit in May '89 and has N10, a friend of mine used to have a 1989 Formula 350 that was an early production car, built in Nov '88 and he did not have N10, his car was original.

 

does the car have rear disks and a posi because as I and a few others of us on this board know the borg warner rears also came out with drum and open carriers if you guys don`t believe me check out 9bolt.com or you can have a look under my car for the proof.

 

ok i have these RPO codes:
gh3: 2.77 borg warner rear
without n10 dual cat option

 

Its funny when people start posting without reading and understanding the SUBJECT POST.....

 

i replied to his first question found in the title:
Can you have a Borg-Warner rear w/out having 2 cats? (89 Formula)

 

??????

 

Clue on subject Post is about a 305 TPI LB9 and not about your 350 TPI L98... Or may be is does not make a diffeence. Well who said that reading comprehension is required on these Forms.

 

I believe cars could be ordered with the 9 Bolt B&W without the dual cats. But in the years the the B&W & the Dual cats were offered I would be surprised if you could order the Dual Cats WITHOUT The B&W axel.

My 87 obviously would not have the Dual Cats, but it has the B&W axel.

In later years, I forget if it was 90 or 91, the 9 Bolt was dropped altogether and therefore you would have Dual cats with the 10 Bolt axel.

The ONLY way to tell would be to look at the RPO sheet.

John

 

I was looking at a friend of mines 1987 Formula Firebird 350. He has a 9-bolt Borg Warner. He is the original owner and his window sticker even has it listed. So I would say YES is the proper response to your query. His car also does not have dual cats.

 

I have a 9 bolt rear on my 89 formula (MM5-LB9 combo), but no G92(borg-Warner) on the sticker. Only G80(limited slip Posi) and GM3, which I think is the 10-bolt 3.45 saginaw rear(weird). Whats up with that? I also have only one cat, which I think is because mine might be either an early production # or as the moderator suggests, it was a dealership demo car and was allowed to delete the N10 and still order MM5- LB9 combo. I thought 9-bolt was a Borg-Warner??

 

89 GTA with a L98 auto with the borgwarner rear 3:27 gears it had a single cat on it had!

 

I have a 87 Iroc with BW rear, SIngle cat, Disc brakes. ALL ORG.
With 3.27