chazman

iTrader: (4)

I know that the N10 dual cats were on hold until the end of the '89 model run. Just wondering about the build dates of those who have an '89 with the N10 option.

Mine was built in May.

JT

iTrader: (1)

I don't know if this helps, but GTASourcepage has a copy of a Product Bulletin about the N10 and that it would appear on all vehicles built (per specified the powertrain) after January 2, 1989. Of course this is the Pontiac side.

http://www.gtasourcepage.com/Pontiac...9cdbs/89F4.jpg

TTOP350

iTrader: (8)

I have 2 89 formula 350s.. I'll have to look..

chazman

iTrader: (4)

Interesting document, JT.


I simply wasn't going to order one without the N10. It's availability always seemed yet another month away for the 1989 MY.

GM kept my car at the Van Nuys holding lot for several weeks after production, until it recieved final EPA certification for the exhaust. I don't think it was released for sale until June.

xcalibur

I have an interesting story to share about the N10 exhaust. My '89 Formula 350 originally came w/o N10, since I hadn't heard about it when I ordered it. About a month after I got the car, the dealer contacted me and offered to put it on. He kept prompting me w/ "Didn't you read about the dual cats in the sales brocure?" I think the Pontiac lawyers were afraid someone would sue them for false advertising or something. Anyway, I had, as I recall, 3 choices: (1) have the dealer install N10, (2) get $500 off a new purchase of any new Pontiac, or (3) get $250 of dealer accessories. I opted to have N10 installed. They dented one of the rear runners in the process, and when I cornered them, finally ordered me a new one. Sleezebags wrote it off as "damaged in factory".

chazman

iTrader: (4)

That's weird, lots of cars were built without the N10 in '89. When was your car built?

TransamGTA350

iTrader: (2)

Built June 1989. Factory N10 dual cats.

chazman

iTrader: (4)

I'm thinking that we won't see any build dates before May.

TTOP350

iTrader: (8)

Finally got around to looking at my junk 2day
My 89 Formula 350 with TTOPs was built on 03/89 and has N10 on the RPO sticker (I can read it clearly)
My 89 Formula 350 Vert was built 10,435 cars later and it has N10 on the RPO sticker
(I can't read the sticker)

chazman

iTrader: (4)

Thanks. Let's see if we have anything before 3/89.

johnnymotz27

I just bought a white iroc with N10 it will be arriving in 2 weeks or so I'll be sure to let you know.

okfoz

Sorry, can't be of any help, my 89 Formula 350 Vert with N10 was shipped on 6-03-89 from Van Nuys and Shipped from ASC on 06/27/89 then to FL

John

chazman

iTrader: (4)

Just to add another little fun fact into the mix....

My car was built in May. But GM held it at Van Nuys for several weeks with all the other N10 cars, until it passed final EPA certification. It must have been June when it actually shipped.

yaj15

iTrader: (3)

Can one of you guys post a sound clip of your cars with the stock N10 factory exhaust? I have never heard an all stock N10 car before. I have read some articles that have said it sounded very nice and sounded better than the TPI single cat exhaust.

Most of the N10 cars that I have seen in person had and aftermarket catback on them. I don't have an N10 car but, catback exhaust was one of the first things that I did to my car so I can't use it as a fair comparison. My stock exhaust was rusting out and a previous owner had installed a very crappy sounding low flowing midas replacement muffler. I also found out later (when I tried to pass smog) that my car had a clogged up cat. My car was way to quiet with that cheap midas muffler.

chazman

iTrader: (4)

Motor Week, (?) tested a new 5 speed, N10, '89 IROC. Should be on You Tube.

yaj15

iTrader: (3)

http://www.youtube.com/watch?v=p4XjQGAnksE

Thanks for the tip. I found this video.

yaj15

iTrader: (3)

The car in that Motorweek video was sure running in fine form. The 0-60 was only 5.9 sec. Thats only a few tenths slower than the fastest stock 350 cars that I have seen in some old magazine articles.

That 13.9 second stock 1/4 mile time was nothing to laugh at either. I hope that GM didn't destroy that car. That car would perform very nicely with some intake and exhaust mods.

That exhaust sounded very good too. Now I see why you guys have a lot of good things to say about it. Had more of a bass grumble to it compaired to the stock single cat TPI cars that I have heard.

xcalibur

Sorry Chaz, I no longer have the car. Perhaps SOME KIND SOUL can figure out the build date from the VIN: 1G2FS2183KL224163. This was a special order due to the (non-Formula) Flame Red Metallic color w/2 tone delete (aka "monochrome"), that I ordered. It came w/o N10s, and they really hounded me to get them put on.

TTOP350

iTrader: (8)

Your car was built 17,086 before my car and mine was built on 03/89 with N10.
Hope that helps.

1MeanZ

iTrader: (9)

My 89 GTA was a factory N10 car built on 3/89. The new dual cat setup was built 3/12 LOL I forgot to look at my VIN and see where in the mix mine was built.

89G92CAMARO

Mine was built in April 89

B4C5.7

iTrader: (2)

N10 LB9 car, built 5/89, last 6 are 197965, may be a moot point but thought I would advise.

Guest

Dear sweet God, a stock LB9 5.0 5 Speed running 13.9!!!!? What?!!! I had been told that was impossible. Anyone know the fastest recorded stock 350 L98 1/4?

yaj15

iTrader: (3)

The lowest 1/4 mile run for a GM factory stock L98 is in the low 14-second range probably around 14.2 seconds.

The LB9/T-5/G92 option cars have a gearing advantage and a transmission efficiency advantage over the L98/700r4 cars. There is a weight difference as well but the gearing advantage really helped the LB9 cars keep up with the L98's and give those 5.0 Mustangs more than a good run for their money back in the day.

Most manual transmission cars loose about 15% of the engines power through the drivetrain to the rear wheels. Automatic cars typically loose around 20%.

Ask anybody who has a 1985 LB9 IROC (this is the most powerful LB9 that GM paired with the 700r4) with the factory 3.42 gears and see how they like their performance. The 1985 LB9's are special and very good performers out of the box and it dosen't take much to hop them up. The L69 style cam and the 3.42 gears really helped make that drivetrain combination a strong performer back in the day.

What I'm going to write below is hopefully mostly correct for the Camaros. I know more about the Camaro thirdgens than the Firebirds. Please correct me if I am wrong.

The fastest 305 TPI's from 1989-1992 had the drivetrain combination consisting of LB9/T-5/G92. That gave you 3.45 gears (9bolt) or 3.42 gears (10bolt).

The 1989-1992 LB9/T-5/G92 cars were rated at 230hp & 300 pound feet of torque if I'm not mistaken. The G92 option also gave you the N10 dual cat exhaust as well.

In 1989 the non-G92 L98's were rated at 230hp & 330 pound feet of torque. The L98 cars with the G92 option were rated at 240hp & 340 pound feet of torque. These gains came from the N10 dual converter exhaust that was a manditory option when you selected the G92 option.

For 1990-1992 the L98's were rated at 245hp and 345 pound feet of torque. I've read that the 1990-1992 L98's got lighter weight pistons and that is the reason why these L98's had 5hp more than the previous years most powerful L98. I don't know if thats true or not.

Starting in 1989 selecting the G92 option included a lot of other factory go fast parts. Before 1989 the G92 option just allowed you to get a steeper set of gears.

The with the L98 cars the steepest gearing you could get with the G92 option between 1987-1989 was the 3.27 gear set in the 9bolt rear. Otherwise you got the 2.77 gear ratio. I've got the 2.77 gears in my car and trust me those gears are good for fuel economy - not for performance.

In 1987 (when the L98 was first introduced in the F-bodies) 3.27 was the only gear option that was available with the L98 in the IROC's - there was no G92 L98 option code in 1987 because of this. Between 1988-1989 the 2.77 gear set became the standard 9bolt ratio and the 3.27's became the G92 option gear ratio.

For the 1990-1992 L98 cars the G92 option was manditory and the Borg Warner 9bolt rear was dropped - you only had the 10bolt rear and were only allowed to get 3.23 gears.

This information is for cars that are 100% GM factory stock however. Once you start modifying cars that equation changes a lot. A higher stall torque converter will really wake up at car with the 700r4.

timfitz63

Not sure of the exact build date on mine, but I was near the end of '89 production. I had ordered it a month or two before picked it up at the dealership Memorial Day Weekend in 1989, so the build date for mine was in the April-May time frame...

I'm skeptical of those numbers too, although I have no solid facts with which to dispute them...

I suspect that the MotorWeek car was tweaked somehow; my Formula has never approached those kinds of numbers. What are the factory-published times on the car...? I'm pretty sure 0-60 mph was sometimes advertised as "under 7 seconds," but I don't recall ever seeing an 'official' 1/4-mile time from Pontiac or Chevy...

This site has numbers (source unknown) for the '89 Turbo Trans Am, which was widely regarded as the fastest production car that year: 0-60 mph in 5.0 seconds, 1/4-mile in 14.0 seconds. It also lists a '91 Formula (presumably an LB9/MM5/N10 combination) at 0-60 mph in 6.4 seconds; 1/4-mile in 14.6 seconds. The MotorWeek times for that 'stock' '89 IROC are a bit suspicious...

chazman

iTrader: (4)

That 13.9 is definitely an outlier. Most other tests of the day had that combo in the mid 14s to low 15s. I have seen some low 14s as well. I will say, that I never had any problems beating 5.0s back in the day with mine, however.

yaj15

iTrader: (3)

http://www.prophetsofmadness.com/iro...7janhotrod.htm

The link above has an article for a 1990 IROC hardtop with the L98/700r4/3.23 10bolt rear drivetrain.

Lists the 0-60mph time as 6.2 seconds

Lists the 1/4 mile time as 14.77 seconds @ 97.7mph

Lists the curb weight as 3,456 pounds



http://www.prophetsofmadness.com/iro...-61990ZvsZ.htm

This link has an article for a 1990 IROC hardtop with the LB9/T-5/3.42 10bolt rear drivetrain.

Lists the 0-60mph time as 6.8 seconds

Lists the 1/4 mile time as 15.1 seconds @ 91.5 mph

Lists the curb weight as 3,471 pounds

yaj15

iTrader: (3)

http://www.prophetsofmadness.com/iro...arcraft1LE.htm

This article has a car that has the same drivetrain as Charlies' 1989 IROC. It's even the same color (black) just has the stripe option though.

This car has the LB9/T-5/3.45 geared 9bolt powertrain.

Lists 0-60mph time as 6.49 seconds, so 6.5 seconds


Lists 1/4 mile time as 15.3 seconds @ 94.7mph


Lists the curb weight as 3,340 pounds

This article also shows the different gear ratios that the G92 option cars got with respect to the T-5 transmission. I'm still confused on this one. I thought the 1st-4th gears were all the the same on the GM LB9 transmissions. I just thought that 5th gear was different. Can someone educate me on that one?

The article says that the car has these following gear ratios:

1st - 2.75 - this is a different 1st gear ratio than I thought
2nd - 1.94
3rd - 1.34
4th - 1.00
5th - 0.74

I thought that the G92 LB9/T-5 cars got these gear ratios:

1st - 2.95
2nd - 1.94
3rd - 1.34
4th - 1.00
5th - 0.74

I thought that the non-G92 LB9/T-5 and LO3/T-5 cars got these gear ratios:

1st - 2.95
2nd - 1.94
3rd - 1.34
4th - 1.00
5th - 0.68

timfitz63

These numbers are much more in line with my own experiences (as a rank amateur goofing off on a drag strip) with my Formula: 6-7 seconds to 60 mph; 15.58 seconds @ ~90 mph in the 1/4-mile.

yaj15

iTrader: (3)

https://www.thirdgen.org/secret_chevys_mt_june_1990

To also deal with the issue of the fastest factory thirdgen Camaros I'll post this article about a couple of 1990 IROC's with the 1LE option.

The black car has the L98/700r4/3.23 gear drivetrain.

0-60 time = 6.1 seconds

1/4 mile time = 14.8 seconds @ 96.0mph

curb weight = 3,340 pounds



The dark red car has the LB9/T-5/3.42 gear drivetrain.

0-60 time = 6.3 seconds

1/4 mile time = 14.8 seconds @ 95.4mph

curb weight = 3,280 pounds

These cars are basically in a statistical dead heat. The marginally higher top end for the L98 car shows that it's higher power rating is giving it a small advantage in the speed at the end of the 1/4 mile and would probably extend a little more if the race kept going.

The LB9 and that steeper 3.42 gearing shows that off the line it can more than hold its own and keep up at the top end with an L98 car. I know you guys all know this but you really have to have good skills with a manual trans to get these numbers on a consistent basis. Also keep in mind that the LB9 has 45 fewer pound feet of torque than the L98 so this really shows off the efficiency of having a manual trans and the effect of steeper gearing.

Again we are talking about 100% factory stock cars here that we are assuming to be in 100% top shape. Age, milieage, normal wear & tear, and modifications all make the numbers subject to change.

Having said that though I love these cars and they are great performers right off the production line. Especially in the handling department there are few cars today that will hold a candle to a thirdgen. Wouldn't take too much work to improve upon these listed performance statistics either.


To me the fastest factory stock thirdgens have to be:

1.) The 1989 TTA pace car with that Grand-National turbo charged V6 engine.

2.) The 1991-1992 SLP Firehawk. I wish all the high performance thirdgens could have come with the kind of performance hardware that these cars got.

okfoz

I was able to achieve 14.7 in my 87 LB9/A4 Formula... Of course I have 1.75" runners, with 1/75" SLP Headers, basically the same cam as the 1989 L98 but higher lift, and the SLP 2 on the left (Firehawk) Cat-back and 3.73 gears... Stock Heads, 9.5:1 compression, Other things are the freebies, like cleaning up the plenum and base to accept the larger runners... My 89 Formula 350 Convertible feels comparable, in stock form... High 14's car...

chazman

iTrader: (4)

I think that we've determined that the 2.75 1st gear stuff is all bogus, they all came with 2.95.

I am virtually certain that the car in the Car Craft story and the one from Motorweek are the same car. 13.9 from one, 15.3 from the other - go figure.

1MeanZ

iTrader: (9)

There were a lot of high 13sec 5.0 Mustangs back then too, funny how Muscle Mustangs & Fast Fords or 5.0 Mustang were always the ones publishing it...

Guest

Okay good, makes me feel better knowing I'm not weird by tweaking out about those stats.

yaj15

iTrader: (3)

That is what I thought that all the 305 V8 cars with the T-5 got the 2.95 1st gear ratio.

The only difference I thought what with the over drive gear (5th gear) being 0.74 for the cars with higher factory performance (LB9's with the L98 cam, L69 etc.) vs. the peanut cam LB9's and L03's for example.

yaj15

iTrader: (3)

At any rate a L98/700r4 car or an LB9/T-5 car with L98 style cam is a car that can give good factory performance and it only gets better with mods.

People seem to go to sleep on the LB9/T-5/G92 drivetrain just like they go to sleep on the L98's or any Gen 1 small block for that matter these days.

With some not all that extensive mods a Gen 1 small block will be able to hang with the newer LS counter parts.

There are also many folks on this site alone that have installed mini-ram LT1 style intakes on their small blocks and have increased their top end performance a lot more than a fully ported aftermarket TPI system.

I like the idle-5,500 rpm band of the TPI system so I'm keeping the stock style long tube runner TPI set up and am just going to get all my parts ported.

chazman

iTrader: (4)

My '89 eagerly revs to 6,000 RPM. In fact, I have to keep an eye on the tach because I could easily over rev it. However, I have ported the the plenum, added an airfoil to the TB and cut out the airboxes. My Crossfire is pretty much all in by 4500-5000 and anything above that is just engine noise.

yaj15

iTrader: (3)

Thats good to know. I'm having my SLP intake runners ported, plenum ported to match, and my 52mm throttle body port matched as well. I've got a custom cold air intake as well. The stock TPI set up isn't as much as a restriction on the LB9's as the L98's like my car though.

When my car was all stock anything after 4,500rpm was just noise and no power. With the cold air kit, cut our air boxes and 52mm throttle body, full aftermarket exhaust from the headers on back that bumped the power band to 5,000 rpm. My engine is still 100% factory GM stock. Hopefully after these next round of intake mods I'll be able to make power up to the 5,500rpm-6,000rpm rev range.

Ha ha yeah Chaz I bet your '89 does get up to 6,000 rpm very easily. The cars with the drivetrains like yours love to rev quickly. The big cam LB9's I thought were an over looked engine in 305 history along with the L69 motors.

Ha ha as you can guess I am a big Gen 1 small block fan and I'm not going to get the 305 vs. fill in the blank argument here. GM already proved with L69 and the LB9/T-5/G92 cars that the 305 can be made to perform well, pass an emissions test, and get good fuel economy - ha ha as long as you can keep your foot out of it. I'm sure thats hard to do with any of the thirdgens that you have. A lot of people are suprised how well these old school small blocks perform with minimal mods that are not as involved as a head or a cam swap.

Since you have two LB9 cars you would be the best person to ask this question for comparison purposes. I'm assuming that after the exhaust work that you did on your '85 IROC that you still kept the factory style single 3'' cat exhaust.

How does your '89 dual cat exhaust car compare to your '85 with the single cat exhaust in terms of power? Is it really a noticable difference? The articles that I have read on stock LB9 dual cat cars say that the dual cat exhaust really helps out performance on the top end compared to a single cat TPI car.

I've been trying to find someone that lives in my area that has an LB9/T-5/G92 equipped car so that I could see how that drivetrain feels. Its hard to find a car that has that drivetrain combination now that is in good shape though.

Your '89 is bad ***! Ha ha I was only 5 in 1989 so I couldn't have bought one new - I wish I was able to though! These threads educate some of the younger folks like me a lot!

chazman

iTrader: (4)

They are pretty comparable. But seat of the pants, the '89 does feel a little stronger than the pretty strong '85 - rest of the drivetrain notwithstanding.

yaj15

iTrader: (3)

Thats what I thought. The magazine articles said that the dual cat LB9 cars had a small but noticable difference compaired to the single cat cars. Nice to hear from someone that owns one to back up wha the magazines have published.

chazman

iTrader: (4)

Obviously, I hadn't test driven a car with my combo before ordering. They just weren't around. But I read all the mags back then and I mean ALL, so I had an idea in my head of what this car would feel like when I picked it up. I was kind of expecting a monster, so on the drive home from the dealer, I did feel a little bit of disappointment. It felt quick, but not as quick as I was hoping or expecting. BTW, I remember reading that 15.3 sec CC 1/4 mile time back then, and quickly discounted it as some kind of weird fluke. The expected time would be about 1/2 second quicker.

yaj15

iTrader: (3)

Yeah thats why I was so surprised from that Motorweek video that had an 1989 IROC with the LB9/T-5/G92 drivetrain posting a 13.9 second quarter mile time.

That time wouldn't surprise me at all if that car in the video had a few intake and exhaust mods but they claim it was 100% GM factory stock - the exact same cars that customers could by. I would like to know if that car is still around now. Ha ha it would have been a good stunt by GM if they hopped that motor up a little and billed it up as all stock.

chazman

iTrader: (4)

I'd say both of those times, from CC and MW are outliers, (and from pretty sure are the same test car). 14.4-14.8 is what I would expect for a *bone stock car.

*Bone stock = factory paper element air filter, factory timing, absolutely untouched from as it came from the factory.

89G92CAMARO

Your probably right. So you think that GM in 89 made only between 3-400 or less with G92, LB9, 5-Speeds, N10 Dual Cats. 12 inch Rear Discs and 3.45??? I have no power door locks, windows, and no tilt steering. Interior is Arctic White with the Black Cloth Interior. Seems Rare to me. Glad that we both have some rare cars here. Not like the 1LE. I would rather have the A/C Street Version which I own. Wonder why GM didn't keep track of these numbers???

chazman

iTrader: (4)

I'd bet that 300-400 number is pretty accurate for Camaro. Figure 1500 total G92s for '89. Figure half the model year without N10. Figure LESS than half of those were LB9/T5.

And I've probably seen a dozen of those survivors being parted right here on this site.

timfitz63

For what it's worth: the best estimate that I've been able to dredge up for the Formula is that 42 were built with the LB9/N10/MM5/G80/GM3 combination during the 1989 model year.

I will readily admit that that number is unconfirmed, but supplied by a source that allegedly worked at GM during that period, and has internal records to back it up. I've never seen those records, though...

okfoz

I would like to see those records if he can still get them.

John

timfitz63

You and me both. The production information I posted comes not from a friend, but what I would call an 'F-Body acquaintance.' In the few conversations I've had with him on the topic, he seemed pretty reluctant to release any concrete information to me (or the public in general, for that matter). I don't know if that means that GM would be very 'unhappy' with him (in a legalistic sense) for doing so, or if he's just producing numbers from his 'rectal database...'

Believe me, I wish I could provide more definitive information. I guess the best advice I can give concerning the production information that I posted is that it's anecdotal. However, that anecdotal information is loosely supported by a Car & Driver article from March 1990 that claims Pontiac only built about 50 Formulas each year with this RPO combination.

okfoz

The problem at this point is the information from 1982-1989 is close to non existent ... The 1990-1992 information is there, but for some reason the early stuff appears to be purged.

timfitz63

Hmm. Well, that may be the problem in this case as well; maybe GM dumped all that information, and he's got some 'rogue' copies that he's not really supposed to have in his possession...? I don't know...?

Not sure why GM wouldn't want that information released publicly, though; production figures are pretty innocuous, especially when they've released numbers for later model years...