A1cRandy

So i've been digging through articles, forums, and plain old "say so's" in order to track down how many of these Sleeper Formulas were actually produced. As you all know, you could not get the 350 TPI in the manual transmission (t5). But you could get the 305 with it, along with, the borg and warner 3.45 positraction diff. unless it were after 1989, in which case the 3.42 was offered. If you had this combination already you more than likely had the dual cat rpo code n10. Not to mention this car was 250-300 pounds lighter than the ol GTA I talked with one of these bird owners and ran across an old Car and Driver article to find out there were roughly 50 of them built each year from 87-92.

I'd like to find some more data in order to track all this down, any suggestions? If not i wouldn't mind seeing if anyone else owned this car at one point or another, or heck if you just wanna throw in your 2 cents.

Slater126

iTrader: (1)

I doubt they only made 50 per year, as 3,300 GTAs came with the LB9/M5 in 1987 alone and Pontiac built 2,000 more Formulas than they did GTAs that year.

If anything, I think there would be more LB9/M5 Formulas than LB9/M5 GTAs, as Formulas were more often ordered as "stripped down" performance cars while GTAs were expensive, loaded touring cars. So if anything, I'd say there were probably 3,500-4,000 per year between 1987-89, and maybe a few more thousand between 1990-92 (when production of the Third Gen was dwindling rapidly).

That being said, I have no idea how you'd find out the exact numbers. I've never seen a breakdown that specific, except in the rarity sticky in this forum, which doesn't speak to the LB9/M5 Formula, much less the other options you cite.

A1cRandy

http://www.camarozone.com/forum/f23/...pokane-177597/

eseibel67

50 per year might be referring to Firehawks.

Back in November of 91, I went into Pontiac store to buy a 92 Formula LB9/MM5/G80/N10/GM3, but there were none available at any dealer within any distance. So I factory ordered it and picked it up on Valentines day, 1992. So I'm sure they made more than 50, but I know they are uncommon if you couldn't even buy a new one at the time.

It was a wonderful car. Pretty fast for back in those days, it sounded great and it handled great.

Slater126

iTrader: (1)

I don't know for 100% certain if the Formula followed the same path as the IROC/Z28 but if it did, then there's a marked distinction between the 1987-89 cars and the 1990-92 cars insofar as the LB9 was concerned.

1987-89 LB9s are easy. 5-speed cars got the L98 cam and 220 horsepower. Automatic cars got a mild cam and 195 horsepower. Simple as that. The N10 exhaust became available for 1989 on 5-speed LB9s, raising HP to 230 on cars so equipped. Single exhaust manual LB9s still had 220 horsepower like in '88. All TPI engines in these years were available with T-Tops.

In 1990-92, you had to order the G92 package to get the most powerful LB9 -- 230 horses. With the LB9, the G92 package included 3:42 gears, aluminum spare, 4-wheel disc brakes, engine oil cooler, N10 exhaust, the L98 camshaft and P245/50ZR16 tires. It was only available with the 5-speed LB9 and not available with T-Tops. Incidently, all L98 cars during these years had the G92 package also, meaning they didn't have T-Tops either.

If you ordered the LB9 without the G92 package it made 205 horses with a mild cam and single exhaust. The 205 horse version was available with either the automatic or manual.

Perhaps because the G92 package was unavailable with T-Tops, 1990-92 N10/LB9/M5 cars seem to be a lot more rare than the 1987-89 LB9/M5 cars. For example, only 733 1991 and 602 1992 Z28s were built with the LB9/G92 combo. I imagine G92/LB9 1991-92 Formulas would be even more rare than that given that they only made about 6,500 total Formulas during these two years!

A1cRandy

You are correct about the g92 cars, but those were only 91-92 as you stated, the lb9's from an 89 91 92 are almost identical except for the cam in the lb9 for 91-92 is slightly different. Other than the weight saving spare and no t tops, cars are almost the same. But number of either or are surely different. I'm detrimined to find something concrete whether it'd be 50 or thousands more.

TTOP350

iTrader: (8)

Just a quick FYI: SLP Only made the 3rdgen hawk in 91-2, 27 ordered and only 25 built.
Started with 8(ish) cars in 91 and the rest being built in 92.

eseibel67

I don't have the exact facts, but if my memory serves, Formula with LB9 and MM5 automatically qualifies for all the go-fast goodies like the 230 hp engine, G80, GM3, N10 and KC4. I would have glady paid for all those items, but they were all included in that configuartion. Sometimes Camaro and Firebird equipment varied in how it was packaged.

zimmstoy

iTrader: (3)

interesting thread. i have one of these cars and am interested in learning more as well. Has anyone gotten the package from the GM Archives yet? I am planning to order one, just wondering if any of the information in it is compelling. I called Pontiac Historic Society and there is some weird year cut off in the middle of the thirdgen run that is being managed by the GM archives now.

A1cRandy

I think i'd shell out a few bucks for that. Seems like you can only look so far.

zimmstoy

iTrader: (3)

I'll let ya know what I find.

A1cRandy

Definitley, keep in touch. I'll do my best also. I appreciate it zimm

Slater126

iTrader: (1)

It's actually more than slightly different. In 1990-92, G92 LB9s had the 202/207 duration and .413/.428" lift cam from the L98. The non-G92 cars had the infamous "peanut" cam of 179/194 degrees duration and .350/.384 lift (basically the 1986 TPI cam but with roller lifters).

http://www.gmtips.com/3rd-degree/dox/tips/cams/cams.htm

If you understand cams, that's a pretty radical difference in practice, especially on a smaller engine like the 305. My 1991 G92 LB9 Z28 actually has a slight lope at idle, pretty amazing for a stock car of that vintage. They even had tachs with different redlines (5,000 for the non-G92s and 5,500 for the G92s).

I do profess ignorance as to how Pontiac packaged the 230 horsepower LB9. I recited how Chevrolet did it. I'd be curious to hear more about the Pontiac side.

A1cRandy

@slater126....we're talking about the car with the 5 speed. The auto 305 has the peanut cam. Specs on an 89 305 lb9/m5....lift 413/430 dur 207/213.....as I said slightly different. https://www.thirdgen.org/tech-data scroll down.

Slater126

iTrader: (1)

Yes, the manual LB9 camshaft from 1987-89 is similar to the 1990-92 G92 LB9 camshaft, with slight differences. I see what you meant. My bad. FWIW, the 1988-89 unit appears to be the most aggressive of all the TPI cams by a few degrees. All 1986-92 auto LB9s and 1990-92 manual LB9s without G92 had the peanut cam.

A1cRandy

Rpo G92 was also an option 87-92, it wasnt till 91 92 that it was offered as a total package rather than just a performance gear ratio. It did not come with weight saving spare, and engine coolers, which were iroc exclusive only.

A1cRandy

In 91 92 it did come with the last part of my post, and as a package. The engine coolers only we're iroc only.

Slater126

iTrader: (1)

One interesting side note is that Chevrolet built 602 1967 Z/28s with the high revving 302/4-speed combination. Then, exactly 25 years later, they built 607 1992 Z28s with the LB9/G92/M5 combo. Not exact but pretty eerie. Either coincidence, on purpose, or a message from the Chevrolet Gods, LOL!

A1cRandy

Haha that is interesting. As far as 3rd gens are concerened they packaged them the same with a few options you could and couldnt get depending on the make. The lb9s in both of our cars get the same power rating the same way. The tach in mine is 5500 and im more than sure your g92 is also. Your gear is the auburn 3.42 mine the aussi bw 3.45. T5 world classes in both. On top of that you have an engine cooler no t tops and an aluminum spare.

Slater126

iTrader: (1)

You are correct.

KMK454

Hmm... maybe my car is different because it's a B4C, but I have the following:

LB9 230hp (not the small cam)
MM5
N10 dual-converter exhaust
Engine Oil Cooler
GU6 w/ G80 - 3.42 posi rear.

Note there is no G92. The 230hp LB9/exhaust/etc are all factory. What's the difference between GU6+G80 and G92? Is it just the manufacturer of the rear end (Borg Warner vs somebody else)?

Slater126

iTrader: (1)

At least in 1990-92, G92 included more items than just GU6 + G80. GU6 is the code for 3.42 gears and G80 is the code for positraction rear axle. G92 was the code for a performance package in 1990-92 that included these and other items N10, KC4, etc.

As to why your B4C does not include the G92 code, my best guess is that B4C, like the G92, was a package that encompassed a group of items. It wouldn't have made sense for there to have been two package codes on a B4C's option sheet, since the G92 items would have been included with the B4C, as well as additional HD components not available with the G92.

To add more confusion to the mix, some B4C cars in 1991 and all B4C cars in 1992 had the 1LE code. Maybe that was because Chevy added the additional 1LE items to the B4C package and these had no independent codes?

KMK454

Only half of the 91s had 1LE. Mine does not have 1LE. The only difference this makes is the size of the front brakes. It's the only performance goodie I'm missing as B4C does encompass the other items. All 92 B4Cs had 1LE.

Back to the G92 vs G80/GU6...

G80 = Posi
GU6 = 3.42

However, G92 equals performance package with the best gearing avail. and posi... but isn't it a Borg Warner rear end? I don't believe the G80/GU6 rear was a Borg Warner rear.

Slater126

iTrader: (1)

Also note that the SPI decal on 1LE cars, at least the ones I've seen, include the G92 code, at least on non B4C models. That's because 1LE was triggered when you ordered G92 without A/C and included components in addition to the G92 items.

Slater126

iTrader: (1)

I don't think the BW rear axle got its own code. I believe all 1987-89 G92/M5 LB9 and all 1987-89 L98 cars had the Borg Warner rear end, in gear ratios ranging from 2.77 (L98 automatics w/o G92) to 3.45 (LB9 manual w/G92). The RPO code for the axle indicates the gear ratio, not the maker of the axle carrier, in my understanding.

I don't think any 1990-92 Camaros, G92, L98 or otherwise, got the BW axle, though Randy says that the Firebirds with the more powerful engines of this vintage may have.

TTOP350

iTrader: (8)

I know the Pontiacs got their own axle codes for the BW rearend in the years they used them due to the maker and gear ratio differences.
They (BW rears) are listed for 89 as:
Axle, Rear 3.45 Ratio GM3
Axle, Rear 3.27 Ratio GW6

A1cRandy

89 was the last year for the australian borg and warner axle, and I also believe rpo codes as slater stated have nothing to do with the type. After 1989 Auburn Gear had taken duty to the Camaros and Firebirds.

TTOP350

iTrader: (8)

Some very early 90 cars got the leftover BW rears (I have seen only 1 tho). Here are the codes listed for the 90 model year cars.

Axle, Rear 3.45 Ratio GM3 (BW)
Axle, Rear 2.73 Ratio GU2 10bolt
Axle, Rear 3.08 Ratio GU4 10bolt
Axle, Rear 3.23 Ratio GU5 10bolt
Axle, Rear 3.42 Ratio GU6 10bolt
Axle, Rear 3.27 Ratio GW6 (BW)

GM&Ws are BW rears and the GU are 10bolts.

A1cRandy

Good stuff right there Ttop350

Slater126

iTrader: (1)

Do u know the code for the pre-1990 2.73 gear set? That was a BW. If it's GM or GW, we definitely have a pattern there.

mantaguy

iTrader: (5)

Not all 86 LB9s had the peanut cam.

okfoz

1) AFAIK GM tips is wrong, all of the cams were the same on the LB9 & L98 cars as the replacement part number in the parts catalogs are the same... The LB9/A4 did have the tall highway gear which really killed Performance.

2) Formulas and GTA's came automatically with the 3.45 or 3.42 gear with the LB9/M5 and 3.27 or 3.23 with the L98/A4 from 1987-1992 in the US. The Trans Am was kind of hit or miss, the Camaro the G92 was the option.

3) If there was only 50 per year for the LB9/M5 in the formula... I own two from 1987... I highly highly doubt it was that rare as it was a very inexpensive way to get a performance car. My wife's LB9/M5 with the custom interior hard top cost less than my LG4/A4 T-top car...

John

mantaguy

iTrader: (5)

What is it with these LB9s,iv'e read that not all 86 LB9s have the peanut cam.I have one,w/5500 RPM gauge,G80,GH3(2.77)MD8,WS6 Package.

A1cRandy

Hey mantaguy check the tech data for camshafts on this site. Just sayin, thats what info there is and sometimes we all have to use our discretion when it comes to what you find on the web. I would try using the most respectable resources.

TTOP350

iTrader: (8)

I don't have those codes, would have 2 look. John do you have them??
I think the
10 bolt was 2.73 GU2 and there was a 2.41 GU1
BW rear was a 2.77(ish) and I have even heard of a BW 2.59 GM1
I'll dig 4 the correct RPOs for each (I'm not 100% sure of these numbers and codes sooo)

mantaguy

iTrader: (5)

I found the info on this site TGO,It says one way to tell if you have the hotter cam is the RPM tach,the hotter cam has the 5500 RPM tach and the smaller cam has the 4500 tach.

okfoz

Interesting findings: 1984 & 1985 were the only years to have the lowest gear ratio of 3.08,

Saginaw
GU1 - 2.41 - 1982 only
GU2 - 2.73
GU3 - 2.93 - 83 only
GW9 - 2.93 - 83 only
GU4 - 3.08
GU5 - 3.23
GU6 - 3.42
GT4 - 3.73

Borg & Warner
GH3 - 2.77
GW6 - 3.27
GM3 - 3.45
G54 - 3.70 (85 & 86 only)

Borg & Warner was only used from 1985 - 1989 There have been some 1990's found with the B&W axle, however none have the RPO code for it.

According to the parts & illustration catalogs no reference to the GM1 2.54... It is a good RPO for a 2.54 axle, however not used on the 3rd gen according to GM's publications.

TTOP350

iTrader: (8)

Thanx John, I forgot about the GH code..
Sooo GH,GM and GW are BW rears. GUs are 10bolts

Aaron91RS

iTrader: (2)

huh?

okfoz

in 91 & 92 T-tops and the 350 were only available on the Formula 350 with the black cross-laced wheels.

Aaron91RS

iTrader: (2)

I am aware of this, thus why his statement made no sense to me

chazman

iTrader: (4)

Which powertrain combo got the GU1 2.41?

okfoz

I suspect the I4... Which would make the car more anemic than it already was, but I do not have that information...

scholtmj

iTrader: (3)

I've asked this questions before as well. The answer I got was "GM did not keep production records for specific options."

I've owned an 89' LB9, 5speed, 3.45 BW car and know of one more locally for sale. I think the 50 car number is false.

okfoz

The truth is... Just because you know of a few does not mean that it is particularly common or rare. For example, there was only 42 Formula 350 convertibles made in 1989... I know of 13 that are confirmed... I agree that indeed there were way more than just 50 LB9/M5/G80,N10... made per any year, as that number is something that a magazine article threw out there a few years back and for some reason it has stuck...

Make some notes:
1) Just because it is on the Internet does not make it true.
2) Just because it is in a Magazine article does not make it true
3) Just because it is on TV does not make it true
4) Just because it is in a book does not make it true either...

There are some things that do line up with reality, and there are those things that do not.

chazman

iTrader: (4)

I agree that the number 50 is bogus when it comes to these cars. I will go out on a limb and say that virtually every LB9/T5/3.45 car ever built was special ordered by an enthusiast. This is certainly not a combo you'd see sitting on a new car lot or ordered for stock. If not 100% of these cars, then 99% of these cars were ordered by 'in the know' enthusiasts, who read every magazine article, studied ordering info in excruciating detail, beyond even the knowledge of the sales person taking the order.

Slater126

iTrader: (1)

Is this a Firebird? As I said earlier in that post you partially quoted, I was discussing 1990-92 Camaros. I said I was not certain what Pontiac did with the Formula.

FWIW, this board's Firebird Tech Data Section says "1990 L98 cars were no longer offered with T-Tops due to supposed CAFE restrictions, although 1989 L98 cars were available with T-Tops." Looks like that changed with certain 1991-92 Formulas, for the section for 1991 says "Firebird Formulas ordered with the PW7 Diamond Spoke Aluminum Wheel made it possible to, once again, order a L98 car with factory T-Tops."

okfoz

I know it has been mentioned before, but all Formulas with the LB9/M5 would have garnered the 3.42 or 3.45 axle and G80... And the N10 from 1989+...

chazman

iTrader: (4)

I know. I was on the verge of ordering an '89 Formula with the LB9/T5/3.45 combo in the fall of '88 but was waiting for the N10 exhaust to be released from it's hold.

I went through the dealer, the Chevy/Pontiac zone office and even contacted Chief Engineer John Heinricy about it. I eventually ordered an IROC with that combo, and even then, it was held at Van Nuys for several weeks until the N10 recieved final EPA certification.

GTA50

A little off topic, but the interesting aspect for me is why GM would carry an inventory of two different 305 engines. For the low numbers of LB9/MM5, why bother for a multi-national corporation.

When I received my info pack from GM's Vintage Vehicle Services, it stated that for 1988 of 1,830 2FW87 models (T/A and GTA), 378 came with MM5. Okay, so the MM5 triggers a revised camshaft. I also compared flywheels between my '91 Firebird (LO3/5 speed) and my '88 GTA (LB9/5 speed). The GTA flywheel is also about 10 lbs lighter.

Why? Somebody or some group at GM had the ability back then to convince the more corporate types to divert from the mainstream pablum. Whoever did that .

On the rear ratios, given my limited experience, but I thought that 3.45 (rpo GM3) was a V-8 rear and that 3.42 (rpo GU6) was a V-6 rear as that seems to be consistent between my V-8 and V-6 5-speed cars.