pj's b4z

O.k... I am really confused about the G92 option for 1985. I've done lots of searching on TGO and the more I read, the more confused I get. If I am understanding this correctly, there were 205 IROCS with TPI, 4 wheel discs, posi, and 3.42 gears in '85. Seems like a low number when most of these options were not that uncommon. Here is where I get confused... I have read on TGO that ALL IROCS had 3.42 gears with the LB9, have also read that 3.42 was only an option (the common belief) , and I am not sure which is true. Sorry for rambling, but I am sure someone here can help me understand why a '85 G92 is so uncommon. Thank you!!!

pj's b4z

Oh yeah... I have also seen SPIDs on TGO with all the right options, but no G92. Was there something I'm missing, i.e. aluminum drive shaft, that also has to be present?

chazman

iTrader: (4)

In '85, I believe G92 was only a "performance axle ratio". For the LB9 it was a 3.42 vs the standard 3.23.

pj's b4z

That's what I was thinking, but for a "performance" car I would think that it would be a bit more common to have performance options.

daveb123

On the compnine site (Canadian cars) it shows 127 cars with G92- 126 of them were LG4/MM5 w/GT4 (3.73s), a combo for which GU5 (3.23s) was standard. One car was LB9/GU6. Obviously the intent of G92, at least in Canada was to upgrade the LG4 cars. Of the 822 LB9 cars that went to Canada, 523 were GU6, and 299 were GU5. It alson seems odd that if there were only 205 G92s, why would such a large portion of them go to Canada?

Drew

iTrader: (58)

My understanding is G92 means an upgraded axle ratio. In the early years, that's clear. It gets blurred in the later years because Chevy had a bunch of upgraded hardware that was intended to compliment the LB9/5spd and L98, the upgraded axle ratio was part of that package so it all gets lumped together as G92. It's more clear on the Pontiac line where the options usually considered as G92 are listed as R6P. Why they used a unique RPO code for Pontiac and used an existing code for the Camaro is anyones guess.

I'm not really familar with all the specifics of 85. I typically only study what I own. At any rate, all the information I've seen shows 3.23 gears as the standard ratio for a LB9/auto in 1985. The G92 option if ordered upgraded to 3.42 gears. To the best of my knowledge there wasn't any other changes when G92 was ordered in 85.

The answer that you're looking for, is probably in the printed materials... I'd start by trying to obtain as much documentation as you can find for 1985 Camaros. A couple invoices, window stickers, and a dealership order sheet, might give you a clear picture.

yo soy el warg

Here's some information I've found on 1985's G92 mystery.

I understand that the G92 option is typically listed as G92 on the RPO list. However, in '85, it would seem that G92 was not so clear. A particular '85 IROC which belongs to 89RESTO (as well as another '85 owned by mr396) has the RPO codes G80, J65, and GU6. The GU6 RPO code appears on the SPID and the window sticker in '85, but not on the invoice.

Another curious part of this mystery, the Camaro White Book has no G92 cars listed for 1985, and the RPO list used to compile the book came directly from GM. It also does not list the GU6 option (3.42 performance axle ratio).

Oddly enough, here's another book which lists that there were 205 G92 IROCs made in 1985:
https://www.thirdgen.org/forums/post...02-post34.html

Here's my example, 89RESTO's IROC:

89RESTO invoice:
https://www.thirdgen.org/forums/post...85-post28.html

89RESTO SPID:
https://www.thirdgen.org/forums/post...77-post34.html

'85 window sticker (not from 89RESTO's car, but still relevant):
https://www.thirdgen.org/forums/post...514-post8.html

Notice that the window sticker lists GU6 as OPTIONAL AXLE, PERFORMANCE 3.42 on a 1985 IROC; would this be considered a G92 car for 1985? If not, then what was the GU6 optional axle?

The window sticker was produced in November of 1984, but is clearly for a 1985 production car because it lists the B4Z (IROC package) option, which was only available beginning '85. This could explain why the window sticker looks very different from my 1985 California IROC window sticker, produced in May of 1985.

Pictures of my 1985 1C5 California IROC's SPID, window sticker, and invoice can be seen here:
https://www.thirdgen.org/forums/post...563-post9.html
https://www.thirdgen.org/forums/post...71-post14.html

I have personally never seen any G92 1985 SPIDs, window stickers, or invoices. I have, however, seen a few which have GU6, as well as everything else which came with the G92 performance package. Could the G92 option have been listed as GU6 in 1985, explaining why G92 has not been seen on any SPIDs from '85 IROCs?

Also, consider that the GU6 was a 3.42 axle ratio in '85, which was (according to Thirdgen's tech pages) the axle ratio defining G92 in '85, only available on the LB9 IROCs:
https://www.thirdgen.org/1985-chevy-camaro

Furthermore, notice that the standard axle ratio for an automatic, LB9 IROC in '85 was 3.23, that meaning that GU6 was NOT standard when B4Z or LB9 was ordered, it was a specified option called the 3.42 performance axle ratio.

Thus, in 1985, it would seem that RPOs don't have to list G92 to be G92 cars, though Thirdgen lists them as such on the tech page. This may explain why the white book doesn't list G92, because it wasn't available; it was listed as GU6. The author of the other book may have seen on the GM RPO lists that there were 205 cars produced with performance rear ends, but decided to list those cars as the typical G92, because it was listed that way in '83, '84, '86, and all the other third gen years; even in years prior to the third gens.

Another user, mr396, is trying to understand this mystery:
Quote:
Originally Posted by mr396
Sorry,I was talking about the 1985 Iroc-Z LB9 with 18,680 made. here are some numbers for the 1985 camaro. They come from Len Williamson, he has taken every production option by code from Chevrolet since 1953 and compiled two huge note books full of production numbers thru 1990. his reference work is used by the Chevrolet customer service. The 3.23 was the standard ratio for the IROC-Z LB9 with the 3.42 option G92. In 1985 the G92 performance axle was only available on the IROC-Z LB9 automatic.
Additionally, the California IROC was optioned with the GU6 rear end. However, none were equipped with G80. So if G80 had to be ordered to receive a G92 performance package, how is it that these cars came equipped with the GU6 3.42 performance axles?

Drew

iTrader: (58)

yo soy el warg, All the links in the top of that post are dead... Notice the ... in the middle? The forum software shortens URL's so you have to either click the original link, and cut/paste the true URL to post it again. Or edit the original post and copy the full link.

That one invoice you reference is an export car destined for Canada. I wouldn't include that data in your research since export cars typically didn't follow the same rules and regulations as domestic cars. The codes, requirements, etc didn't always apply the same way.

yo soy el warg

You're right that it is for an exported car, and it would appear that it is a dealer window sticker and not an invoice, considering invoices show suggested retail and dealer prices while the image I posted has only dealer prices listed (as is common with window stickers). However, I feel that it is compelling paperwork to assume GU6 was a performance option on the LB9 IROC only, regardless of export status.

My California IROC doesn't list the GU6 on the window sticker, neither does it list the GU6 on my invoice nor 89RESTO's invoice. Though both SPIDs do show GU6, which is a 3.42 ratio (offered only for LB9 IROCs), matching the G92 definition.

okfoz

I am not sure about Chevrolet in 1985, but as an example for 1987, I know that a Formula or GTA with a 350 or a Formula or GTA with a LB9/M5 got everything that would have been considered "G92" for a Camaro. Is it possible that the IROC got the equipment standard? And possibly that the G92 was reserved for the Z28 as a performance option??? Look in that direction, I would be interested to see what you find... I know by looking at some dealer information that in 1986 G92 was available on the Trans Am, but in 1987 it was not... It may be more complicated than you think, but once you figure it out.... it will make sense and the planets will align ... more or less.

The 205 number... for some reason seems off to me, I have posted it and I have seen it in several places, but it just does not seem right... Although it may be 100% accurate, it may be an export only thing even...

pj's b4z

Thank you, everyone, for your responses. Been wondering about this sinse I found on TGO that I may have one of these cars... I am now waiting for a few extra bucks so I can try to get a dealer invoice. (the economy in Michigan still sucks!) okfoz- The 205 production seems really low to me too; must be something behind it that changed in later years. My car is a '85 IROC, LB9, 4 whl. discs, and a posi 3.42 rear... and I can find no evidence of ANY mechanical upgrades. (Bought her from the second owner... She had ownership sinse '86. She also told me that she had the console lid replaced... no SPID. ) Anyhow, thanks again; keep the info coming! Can't wait to get an invoice, will let you all know what I find. -Phil

cs2000

see below.............

cs2000

Here is a little info on the G92 performance axle ratio for the '85 Camaros, In '85, the G92 option was available for Z28 Models without the RPO B4Z IROC-Z package, it up-graded the 3.23 to a 3.42 axle ratio, It is a little complicated but this is how it was: When you ordered a Z28 with the LB9 TPI Engine the standard gear ratio was a 3.23, when you ordered the Z28 with the LB9 TPI engine and the B4Z IROC-Z package you automatically got the 3.42 Ratio, but you could up-grade the Z28 (without the IROC package) to the 3.42 Ratio by ordering the G92 Performace axle ratio, thus 205 cars were ordered this way. so technically by ordering the Z28 with B4Z(IROC-Z) AND LB9 engine forced the option G92, even though G92 will not appear on a IROC's SPID label. just a note about the J65 4-wheel disc brakes option, this option was open to all Camaro models, it required option Code G80 limited slip axle , and was also available for the Base sport coupe and Berlinetta but required the G80 axle and the LG4 V-8. Chris

yo soy el warg

I've thought the same thing about the base Z28 before. Have you ever seen an SPID for an '85 Z28 with G92? Did you read this somewhere? I'd be interested to see where you found that info.

I'd also like to see an SPID for an '85 IROC which had the 3.23 gears, and wasn't automatically upgraded to 3.42 gears, if anyone has seen one. Guessing by the information on Thirdgen's tech page, there should be some around, unless it's wrong and all IROCs were upgraded to 3.42 as you said.

Also, you said that J65 could be ordered on all Camaro models, but only with the G80 axle. I have a '85 California IROC with the GU6 3.42, J65 disc brakes, and no G80 option (window sticker, invoice, and SPID linked above).

Another interesting bit, here's some original documentation stating that G92 was an available option in 1985:
http://www.iroc-zpostforum.com/Tech/TEch85codes.htm

Drew

iTrader: (58)

That's not necessarily GM information. Those are scans from the Catalog of Camaro ID Numbers 1967-93 Copyright 1995.

yo soy el warg

Drew your right about the scans. This also has some errors, such as the HP for the LB9 with an auto which says 190 HP. It is corrected to 215 HP in very light red print at the end of the last page. I also noticed it didn't have the RPO B9K which is on my car's SPID ( I think?), for door moldings.

scottmoyer

As for cs2000, I believe he works or did work for a dealership in Wisconsin. He hasn't posted much in the past 10 years, but the information he has provided has always been in areas that were questionable, like the 85 G92 issue. I would take the information he presents and mark it as correct and now documented as best we can get. I did see the window sticker showing J65 and no G80 on your car. I thought that was interesting.

calroc

I've seen quite a few '85's with J65, without G80, mine included. My window sticker has been floating around this sight as well as other sights for over ten years.

cs2000

The info I provided was from the '85 Chevrolet order guide, Just a question for calroc, I see on your window sticker the J65 option but not the mention of the G80, Does G80 appear on your spid label?, what about your actual axle code on the axle? I'm just interested in knowing if your car actually has the limited slip axle. Also I see it came from Gilroy, Ca. I went through Gilroy once, isn't it the Garlic capital of the world? And yes, I did work for a Chevrolet Dealer parts department for 10 plus years... Chris

Drew

iTrader: (58)

So if I'm reading this right, then the grid in the tech data for 1985 needs to be changed... The standard ratio for the IrocZ LB9/Auto should read 3.42. Z28 LB9/Auto optional ratio needs to have 3.42 listed.

I'm not sure exactly where that information originated. Most of it was already there when I worked with the database info.

yo soy el warg

It's good to hear from you calroc on the History/Restoration section. You've been a member for 10 years! Wow!

I've seen the window sticker for your 1C5 California Iroc-Z, but haven't ever seen a copy of your SPID. Is there a site where it is posted? If not could we get a picture of it? I know you bought your car new and originally it had the RPO GU6 or 3.42 gears, I'm also wondering if your car has the B9K RPO?

I looked in the Camaro White Book and on page 101 it says that RPO J65 (front and rear disks) required the RPO G80 limited slip axle only before April 1985, and required a 305ci, 165hp engine with Sport Coupe or Berlinetta.

My 1C5 Iroc-Z was built in the third week of May and came without the G80, but also had the J65. What month was yours built?

I wonder why they didn't require the G80 after April of 1985 to get J65? Did it stay like this in later years?

calroc

It does not have G80, and did not have limited slip originally. Also, my car's final assembly point was Van Nuys. From there it was delivered to Guaranty Chevrolet Motors, in Santa Ana, CA, then moved to MacClean Cadillac in Tustin, CA, where it was first titled, all within a few short miles from Van Nuys, all in SoCal. It's never been to Gilroy, which is in NorCal, near San Jose. Maybe that's another window sticker you're referring to??
yo soy el warg, My spid is not posted anywhere, but it is intact, in my center console glove box. Invoice says shipped 5/17/85, so yes, After April '85. Yes, B9K is on my spid. Isn't that for side mouldings? My car was delivered without them!

yo soy el warg

cs2000 you're getting my 1985 1C5 Iroc-Z window sticker mixed up with calroc's 1985 1C5 Iroc-Z's window sticker which I've seen on line and I believe it was delivered to Guaranty Chevrolet Motors in Santa Ana, California. I know that mine and calroc's cars don't have the G80.

My actual axle code is 9PE, but I don't know about calroc's . Mine is a 3.42 without G80 limited slip. The 9PE axle isn't listed in my GM repair manual for 1985. Also, out of 24 axles listed for 1985 it is the only one beginning with the number 9, all the others begin with an 8? Is there something unique about these rear axles without limited slip that were the only ones installed on all 1C5 California Irocs in place of the G80 limited slip axles?

The 1C5 Irocs couldn't be ordered with the options you wanted as you could on any other Iroc. GM didn't take orders for them. They just built 502 of them in red and black, all with the same drive trains, various interior options, with hardtops & t-tops, then distributed them to California dealerships. You'd think that GM would have built them with the best performance options available for 1985. Why then would they leave the G80 off of them?

Maybe they just ran out of G80 axles, since all these cars were made at the end of the 1985 model year? For some reason GM also made the J65 available, which are on all 1C5 Irocs, without having to order the G80 after April of 1985.

Your right about Gilroy California being the garlic capital of the world.

yo soy el warg

Before we jump to this conclusion, which might be right, does anyone have a 1985 Iroc LB9/Auto with the GU5 3.23 standard gears on its SPID. If anyone does or if someone has seen one could you post a picture of it. That would tell us if the grid in the tech data for 1985 is right or wrong especially if no GU5 3.23 turns up for an Iroc-Z LB9/Auto in 1985.

Since we're on the subject of the tech data, I also noticed that on the 1991 and 1992 charts it has (Z-28 & Iroc Convertibles) with the production numbers under it. It should just be (Z-28 Convertibles) the Iroc Convertible part might confuse some to think they were still being built...

yo soy el warg

calroc, My 1C5 California Iroc-Z's invoice has the shipping date as 5/20/85. Yours was shipped on a Friday the 17th of May 1985 and mine was shipped on Monday the 20th of May 1985. They may both have been built on the same day! Mine also has the B9k on its spid. It has door side moldings. I'm also still trying to figure out RPO Z5V on my spid. If you find anymore info shoot me a line. My spid, invoice, window sticker, and picture are above if you want to take a look.

Drew

iTrader: (58)

That's a carry over from when that chart used to be one giant grid covering 1982-92... It was chopped up along with the rest of the info into year by year tidbits. That change might make it easier for someone to find specific info on one year, but it kind of eff'd up the entire thing since it was written originally in a format that built upon each year. Explaining something that changed from the previous year doesn't always make sense when the reader hasn't read the entry for the previous year. It doesn't help that details have been edited into the original document in such a way that it's often confusing.

Black_Knight

I've got a 1985 Pontiac Trans Am with 4-wheel disc brakes and the LB9 (305TPI) engine. It is a very well optioned car from what I can tell. Though I don't know what it has in the way of gear ratios. I believe it has the 10-bolt rear end. Without the RPO codes, how do I tell if the car has the G80/GU6/G92 options? Is there an easy way to do so?

Drew

iTrader: (58)

Not really. You can determine visually what components are on the car, but you won't know if the components are original to the car. Take a look at the rear end. 9-bolts are painted black, have 9 cover bolts, with a rubber fill plug, and they have the Borg Warner logo cast into the center section. 10-bolts are bare steel, 10 cover bolts, drain plug screws in on the front side of the housing.
G80, or limited slip is just as easy if not easier to identify. Turn one wheel and watch the other, does it turn the same direction? Limited slip they turn the same direction, if they go opposite directions it's an open rear. To determine the axle ratio, mark a tire and the driveshaft. Count how many revolutions of the tires for one turn of the driveshaft and you've got your axle ratio. If you want to be exact, pop the cover off the rear and turn the ring gear till you see markings stamped in the edge. They'll either have the exact ratio, or the number of teeth. Divide the numbers and you have the ratio.

Truth told Pontiac options aren't always the same as Chevy. It's probably not relative in this case.

yo soy el warg

Check the axle code, if it's not too rusty. I think it's on the passenger side. The axle code can be referenced online, and would indicate whether or not it is the original rear end, if your car came with G80, the gear ratio, day and shift it was made.

yo soy el warg

Here is a 1985 Iroc-Z SPID that has the base LG4 engine and automatic. It is equipped with the GU4 3.08 axle. Not the GU5 3.23 that the tech chart shows as the only ones for both the M5 and A4 applications. This is another discrepancy in the 1985 tech information that can only be corrected by verifying it with actual specific applications that are listed on various vehicles' SPIDs as they are found.
Changes should only be made to the tech information page when it can be varified with these SPIDs.
Here's a link to the tech page:
https://www.thirdgen.org/1985-chevy-camaro

Drew

iTrader: (58)

I'd like to know exactly where Pierre-Henry Marbot got his information. To the best of my knowledge, that chart was lifted directly from his original Camaro Technical Database document. http://www.f-body.org/tech/tech.htm I'm not sure who wrote the two or three paragraphs of Firebird info that were included when the Tech database was added to Thirdgen.org. You can blame me for having entries under every year for the Firebird, but it's been edited a couple times since then even. I've offered to touch up some of the errors, and never heard anything back from the admins. Honestly, it needs serious work and a lot of research and documentation to be accurate. I'm not sure that anyone really cares enough to make it worth the trouble. It's all just trivia to most of us that do care. The average person just wants to know some basic info on their car.

JT

iTrader: (1)

The paragraphs that were included with the Tech database date as far back as atleast 2001 as there are records of it. When the website redesign occurred in 2006, most of the information was simply copied/pasted and organized into seperate years using the new content management system. The Tech Data, prior, was simply one single large webpage. I recall previous staff and myself doing some of this and it was mostly copy/paste work from existing material on the server. I wouldn't doubt that some information may have been edited along the way, but much of it came from existing material.

I do recall your offer to help and I do recall replying. I recall it was a side comment here in the History/Restoration forum inside an existing topic. I can't recall the details, however. I do know we'd have to do some tweaks to give you the proper permission to edit those pages with the content management system, but I'm sure it can be done if you really are interested. If you are interested and can help fix/update the tech data, by all means, let us know.

Thanks.

okfoz

Obviously the information is speculative at best, considering that it shows 50 L98 Camaros being built...

John

yo soy el warg

I think he forgot to mention that they weren't production models available to the public. I've have yet to see one? I'd also like to see one of those 74 1986 L69. Since those probably do exist.

daveb123

After reading all of this, I think it would be a great idea for the mods to make the SPID thread a sticky- Maybe more folks would post theirs up, increasing our knowledge on all these issues.

cs2000

here is some info I have on '85 LG4 axle ratio combos, with Auto, 3.08 (all models), with 5-speed, 3.08 except iroc package with 4 wheel discs, 3.23 for LG4 5-speed IROCS WITH 4-wheel discs, Chris

Drew

iTrader: (58)

My edit must have been sometime around 2000. That's about when I remember working with it. I know some details were changed after that, before it was broken up into it's current one year at a time layout. Back then it was one text or html document. I made the changes and then emailed it to Dirk and he uploaded the page onto the server. The version I sent him was actually just a rough draft that still had a lot of rough edges, but that's the version that got uploaded and eventually evolved into what we have now.

The problem I see is there are so many variations, across so many sub-models and option packages, that the information gets muddled. To make sure the information is accurate, I think more then one person should be verifying the content before it's uploaded. I think it'd take a lot of documentation to make sure it's accurate, and that documentation would be expensive for one person to obtain. If several people were involved scanning documents, and contributing information it might alleviate some of that expense but then it becomes more difficult to keep the information categorized. It'd be a ton of work.

JT

iTrader: (1)

We can have multiple people involved, but all involved probably doesn't need need access to edit that information. They can submit it to us, or mark it to our attention. I don't have a problem with someone like you having the access, if need be.

I have not really made changes because, like hinted, I don't think it would be wise to change things unless there was hard evidence (documentation). I did change the Notchback figures as it initially stated there was 624 and that they were identified by a "K" in the tenth slot of the VIN. I have two documents directly from Pontiac that stated there was a total of 718 Notchbacks with 624 of them being domestic while the rest were exported. The tenth character in the VIN of "K" was wrong as it would mean they were 1989 models. That is one of the very few things I've changed because I found direct documentation from Pontiac to warrant the change.

This is actually why I think a wiki would be nice, and I was setting one up, so that we could allow "trusted" people access to edit/update the content on their own with edits being logged for integrity of the information. I still think that would be good, as our current software doesn't exactly allow this so easily - but probably will soon as we're looking into an upgrade. Problem is, the key people just don't have time. I can update information (do the technical stuff), but there should be some people doing the research stuff - and the latter group seems to be busy.

yo soy el warg

Could this RPO Z06 be what the "G92" option was on those 205 1985 Camaros that supposedly had it? Look at the SPID for 89RESTO's 1985 IROC-Z below. I noticed it had this RPO Z06. I don't think I've seen it on any other 1985 IROC-Zs. Notice at the top center of the invoice for 89RESTO's, 1985 IROC-Z says Chevrolet Motor Division, General Motors Corporation, Central Office where the order was placed. I read somewhere that 89RESTO had his uncle who was working for GM place his order. At the top center of my invoice on my 1985 IROC-Z it says CHEVROLET MOTOR DIVISION, General Motors Corporation, Detroit Michigan where the order was placed. A possible COPO? (Central Office Production Order) with the Z06? Was this the only way to get Z06 in 1985? Anyone heard of Z06 in 1985?

89RESTO invoice:
https://www.thirdgen.org/forums/post...85-post28.html

89RESTO SPID:
https://www.thirdgen.org/forums/post...77-post34.html

mr396

I think the Z06 is for the "Camaro" interior. Still I wonder about the central office order.

yo soy el warg

The RPO code for the "spectrum contour interior" or "Camaro, camaro, camaro" seats and door panels as they are known on this Iroc-Z is the 19D on the SPID Sheet. On the invoice sheet it's also got 19D with the FBB9 Black custom sport listed. So the Z06 must be for something else. That's why I think it's related to the G92 performance package.

Here's a link to the 19D Contour Custom Cloth RPO:

http://www.iroc-zpostforum.com/Tech/TEch85codes.htm

Here's some links to 89RESTO's '85 IROC. He has the seats and door panels which are designated by 19D, but also has Z06 on his SPID.

https://www.thirdgen.org/forums/post...43-post43.html

https://www.thirdgen.org/forums/post...47-post44.html