cbd1

I was just reading about Firebirds on Wiki, and although I know that the data there can be questionable, I came across this statement. IS there any truth as to the rarity of these cars? My car is a black 89 with t-tops and these options.

"The N10 option remained available throughout the balance of the Third Generation production run, however the L98 powerplant was only available with an automatic transmission, whereas the LB9/N10 combination could only be coupled to a 5-speed manual (RPO code MM5) and a limited-slip differential (RPO code G80) using a 3.45 axle ratio (RPO code GM3). According to a March 1990 (Vol. 35, No. 9) Car and Driver article, when the latter set of options were combined into the 300-pounds-lighter Formula body, which shared same WS6 suspension with the top-end Trans Am GTA, it created a high-performance "sleeper" that could out-perform the heavier Trans Am GTA (even when equipped with the L98 engine) — at a roughly 30% lower sticker price. Although not an exhaustive comparison, these claims would seem to be supported by a simple examination of the weight-to-power ratios of both models: a 230 hp Formula at a curb weight of 3,300 lb. versus a 240 hp Trans Am GTA at a curb weight of 3,600 lb.; the weight-to-power ratio for the Formula is 14.3 lb/hp compared to 15.0 lb/hp for the Trans Am GTA. According to the same Car and Driver article, very few of these "hopped-up" Formulas hit the streets; only about 50 were built each model year, as almost all LB9-equipped Formulas came with an automatic transmission — which disqualified them from receiving the high-performance N10 and GM3 options.

al8apex

I would say that number is way off, I think there are LOT more than that built

it IS true that the LB9 a4 cars did NOT get the N10

I owned several Formulas but only one LB9 N10 mt car, it was a 92

pretty rare car

I did have a LOW performance 89 T/A mt TPI 305 (220 hp, they were BOTH called LB9), it was a "base" car, no 4wd, no N10

it was Jan of 89 when the N10 option made it's debut

pretty sure ALL G92 (performance axle ratio) cars got the N10 pipes, regardless of engine

My understanding is the mt cars got the 3.45 in 88/89/early 90 (australian Borg Warner axle) years

when they changed to the Auburn rear axle in mid 90 production run the mt cars got the 3.42 ratio

Interesting note is that ALL 5.7 Firebirds got the N10 system (after it was avail) and ONLY the G92 Camaros got the N10 exhaust. There are 89-up 5.7 IROCS with the single cat ...

GM3 is the production code for that mt ratio, none of the a4 cars ever got that ratio, regardless of engine

okfoz

Some things to clear up...
1) There were probably more than 50...
2) Yes the Formula was lighter than a TA and therefore was faster.. Otherwise they were the same as the Ta/GTA as far as the running gear. The Engine, Trans, rear axel would be identical on the Formula as it was found on the Trans Am.
3) the LB9/M5 combo did mandate the N10 dual cats on the Firebird line. Originaly it was only to be installed only on the Formula, with either the 350/A4 or LB9/M5, but mid year they changed this and all of the firebirds would have recieved the N10 when equipped with the 350/A4... I believe it was also true for the LB9/M5 as well, but not 100% on that one..
3) Unlike the Camaro Z28 & IROC Pontiac took a different direction when adding performance to their cars. When a customer ordered a GTA or Formula they got the performance goodies.. Especially when they were equipped with the LB9/M5 or L98. Where the camaro the "G92" was an option, it was standard fare on the GTA & Formula... THe Trans Am however had another option (I think its R6P) which would bump it up like the G92... In Formula & Trans Am cars if you got the G92 then it bumped you into the 1LE package, whereas the Camaro G92 did not mandate the 1LE, the 1LE was another package...

As for the rarity of the Formula with the LB9/M5/3.45 cars, I own an 87 Formula with just that combo... I do not suspect the're that rare. Granted I know of a few other cars with that combo, I cannot recall actually seeing one in person, just on line...

al8apex is correct that there were no Automatic cars from 1986 & up with the 3.42 or 3.45 rear axel. THe highest gear yoiu could get with an Auto was the 3.27 or 3.23 depending on your year.. The reason was for fuel economy, as the Autmatic was slighly less efficent than the Manual, With a manual at 3.42 the efficency is about the same... about 5%.

John

LAFireboyd

iTrader: (3)

I'm going to 'second' that entire paragraph...

I, too, own one, also an '87(though the topic is about the '89). I also have never seen another one in person, but I've seen several online. They're not supposed to be 'rare,' but they sure seem to be hard to find.

Not to get off topic here, but here's another car that should be much more elusive than the 3.45 cars: 1985/'86 Trans Ams with L69/M5/3.70(9-bolt) combos. Those were produced in very limited numbers and ONLY during those two years. Yet I've found two of those in junkyards, whereas, through all my junkyarding(and I do A LOT of it), I've NEVER run across a 3.45 car.

I know that the people here hate the R-word(rare), and they'll line up to someone who uses it, lol... but it sure would seem that, by observation alone, the 3.45 cars are apparently a lot more 'elusive' than people think and would definitely be pushing towards that R-word category.

And what do they say? "If it walks like a duck and quacks like a duck..."

okfoz

LA,
I was a little confused when I wrote my post. On the one hand the thread is "89 Formula LB9/N10/MM5/G80 prod #'s?" but the last sentance in his post states that there were "only about 50 were built each model year" So that is why I posted about my 87...

John

LAFireboyd

iTrader: (3)

It's ok to get confused once-in-awhile. But don't let it happen very often because we all count on you!

But I was agreeing with you about the elusiveness of the, what would be, MM5/G92 Pontiacs(if they'd have been so technically-optioned, which they were not from '87-'90... not sure about '91-'92 though), which is what I thought you were intending to say by posting about your '87.

And by posting what I did, I was just showing that, yes, they are definitely very hard to find, no matter what their production numbers were--even harder to find than some of the least-produced combinations of the generation.

cbd1

Thank you gentlemen. I am about to drop in a vortec headed 355 and reuse the L98 cam from the LB9. Then I was just going to dump the original motor.. I think I'll reconsider trashing it. Thanks!!

okfoz

I think all in all the production would look like this year by year.

LEAST to MOST produced. 1987 thru 1992 (GUESSTIMATE)
LG4 or LO3/MM5
LB9/MM5
V6/MM5
LB9/A4 or L98 (depending on the model year)
L98 or LB9/A4 (depending on the model year)
LG4 or LO3/A4
V6/A4...

For example in 1989:
TOTAL production: 64,404
Manual Trans: 9,107
Automatic Trans: 55,297
LB8 firebirds: 4,565
LO3 cars: 18,362
LB9 cars: 6,478
L98 cars: 13,041
TTA: 1555

Therefore the formula would look something like this
9,107 / (64,404 - (1,555-13041)) = 18.284%
If ALL things were equal and the manual trans was evenly distributed between the engines which it was available:
.18284 * 24,968 = 4,565 LB8 (v6) engines with M5
.18284 * 18,362 = 3,357 LO3 engines with M5
.18284 * 6,478 = 1,185 LB9 engines with M5

But thats a guestimate, It would be easy to assume that the bulk of the M5 trans were installed in the V6 cars even more than what are listed above. As there were fewer LO3 cars with the M5 than the LB9 with the M5, as I am aware of only a handful for the entire production run from 88 - 92... I would not be surprised if the LO3/M5 cars were less than 500 for each year.

In 1989 since the 350 was available with T-tops it would mean that more people would opt for the combination than go with the LB9 engine, as the difference in additional price was not overly significant, about $300. When in that position and talking about a $13,000 to $20,000 car I do not know many people who would opt for the 305, unless it was a dealer making inventory and trying to cut costs...

I would think that its probably worth keeping as is, or at least keep the original parts so you can revert back...

John

neubauej

They cant be that hard to come by, I have 2. Both are identical except for the exterior color.

'89 Formy, lb9/n10/m5/g80/ws6, 4 wheel disk brakes, power windows and locks, grey cloth manual seats, lexan t-tops, air, cruise, tilt, etc. One is black, the other white. I love 'em, but I kinda doubt they are all that hard to come by.

stacylaray

I special ordered this car and had to wait 6-weeks for it to arrive. You had to special order it with this combo.

okfoz

In 1989 there were the following with the LB9/MM5/MK6/GU6
1,126 Formula
26 Trans Am - (All 1LE)
523 GTA

John