what are the main differances to it and how do i know if i have one? are they rare?
will it baeat an 88 mustang gt 5-speed?

 

Sorry this doesn't help any, but...

There's better cars on the road to worry about beating than a Mustang.

 

---------------------------------------------
There's better cars on the road to worry about beating than a Mustang.
---------------------------------------------
Yes but, they are like little masquitoes buzzing around your head and you just want to swat them .

------------------
www.geocities.com/camaro1j/myz28.html


406
accel supper ram
6000 rpm Hyd roller cam
afr heads
spohn torque arm and crossmember
t-56 trans, [wier racing bellhousing and hydrolic throwout bearing]
9" ME rearend 3.91 Gears

 

lol!

 

The G92 car This is a car you will often hear me talk about, but I am the first to admit, I don't know every little thing that was changed for these cars. Here's what I "HEARD" was done to them and what I've seen. They are a 305/5spd car.

Things I know...
-Dual Cats
-Larger profile camshaft (similar to the 350's cam, maybe a tad bit larger from what I understand.)
Things I've HEARD... (sounds like a 1LE)
-Koni front struts
-Gas tank baffling

These cars are abnormally fast from the factory. They WILL, not maybe, but WILL in every case, beat a L98 car in the quarter mile, stock for stock. Expect to see low timeslips (low 14's, sometimes high 13's) STOCK. I beleive the G92 option was a requirement for the B4C 305 cars.

You can tell if you have a G92 or B4C car by looking at your cars RPO sheet, which is normally taped to the lid of the glovebox. Just look for G92 or B4C.

 

Slow Iroc, not to flame you, but your post is is misinformed.

NO, G92 305s DO NOT get a bigger cam than an L98. The 5 Speed 305s got the same cam as an L98, and the SD 305 autos appear to have the same cam too.

The biggest difference I've been able to identify with G92 is the rear disk brakes. There are a LOT of differences over the years from model to model. But the one consistent difference that I can see between a G92 and non-G92 is the rear disk brakes. My non-G92 SD L98 has ALL of the options of a G92 SD L98 EXCEPT the rear disk brakes.

As for a G92 5-Speed 305 ALWAYS beating a L98 HA HA HA. Better tell that to all the 305s that I've dusted.

Truth be known, the 5 Speeds were VERY CLOSE to performance of the L98 within a couple of tenths. A good driver can make up that difference. I have TONS of magazine articles on the 3rd Gen F-body and the typical times for the car were:

305 auto: low 15s- high 14s
305 5-Speed: high 14s-mid 14s
L98: mid 14s (with the odd magaizine showing 14.2)

Those are all for the SD cars, which are typically .2 quicker than MAF cars (based on magazine tests).

In real life, a 305 auto gets beaten by a Mustang fairly bad, a 305 5-speed hangs with, but still losses to a Mustang and an L98 hangs with and squeezes by a Mustang.

Again, all stock.

There are production variances from engine to engine making one car slightly quicker (more often slightly slower) than another similar car.

But in all of my years of being around these cars (I've owned my since new for 10 years btw), I have NEVER seen a bone stock 305 or L98 (TTAs and Firehawks not included) break into the 13s. And, I lived in a location that has cool climate and was at sea level.

[This message has been edited by Glenn91L98GTA (edited May 29, 2001).]

 

jusy my .02, my 87 is a 305 auto, sorry to say, runs great nuntheless, but i have the G92 rpo and all i can tell it is for the performance axel, GU5 3.23 ratio, G80 limited slip, J65 power disc front and rear
so what is performance axel?

------------------
TPIS airfoil,relocated MAT,AFPR,TB h2o bypass
March Underdrive Pulleys
otherwise stock 5.0TPI
700r4, 10 bolt 3.23 g92 axle, 4 wh. disc brks.

 

i think ill go ahead and ask this, this post seems to be a pretty good place.. what year were rear disks first put in, and how rare (or common) are they in 91 and 92 cars? i've looked for information on this for a while now, but cant really come up w/anything. I'm getting really close to buying my second thirdgen, and I've narrowed my search down to a 91 or 92 Z28, red or white, L98. I have no idea how many of these cars have rear disks.. but need/want to find out

------------------

• 83 Z28-- not a pretty site to look at, 200k miles and im sure it was treated like a rental car every day of its sad life(before i got it).. sold, thank the lord
• 74 Z28-- 383/400, green on black. pretty clean. FOR SALE!!!

 

I thought the RPO "G92" was for nothing but the performance ratio axle... disc brakes and all that other stuff have their own RPO codes, regardless if it has the G92 or not. 305 vs. 350 has nothing to do with it, either.

KAM

 

Thunderstick, the RPO G92 is described as "Axle, Performance Ratio". But you can have both an auto with 3.23s (GU5) that are both posi (G80), yet one can be G92 and the other not. They can both have N10 (Dual cats) and virtually the same options, the biggest difference is one will have Rear Disk (J65) and the non-G92 won't.

I am starting to think that G92 forces you to have Rear Disk (J65) similar to L98 triggers B2L (Engine Package - V8 5.7L, PFI). I am curious if anyone has G92 without J65 or vice versa. That said, I am willing to bet someone can produce a car identical to mine, including the Aluminum Drum Brakes and have EVERY RPO the same as mine...except he'll have G92 and I don't.

But so far, every GTA of my model (with the L98) that I have seen that has G92 had the disk brakes and those that don't, don't have rear disk brakes.

 

i have a G92 '87 IROC..

as far as I've been able to discern they got a beefier rear-end made by Borg Warner and the ratio was not 3.23 but was 3.27..

there was a big hubbub on my website about it awhile back and I got shot down big time by a guy who has an '88 L98 G92 car..

other than that, I think that's it.. stronger rear axle and slightly low gears..

i DO know this, there are not many G92 cars

------------------
Webmaster: www.IROC-Z.org

 

to answer mtx28's question,i have a friend that owns a 83 Z28 that has rear disc brakes,and his sister has an 87 IROC that doesnt have them.so unless his brakes are aftermarket,which i doubt cause it used to be an older persons car,then rear discs were available since atleast 83.i dont know how rare or common they are in 91 or 92 cars.i have a 91 RS that doesnt have them,and a convertible same year that i looked at didnt either.so i really dont know.

------------------
-1991 camaro rs,dark red metallic,t-tops,stock 15inch rims
-stock L03 305,th700r4,only mod for now is a flowmaster 80 series replacement muffler.

 

i do know that in 1992 there were 3,645 cars built with the j65 rpo whereas 3,056 had the g92 rpo, so logically there could be cars with rear disk brakes and not the g92 performance package. i would be interested to find out how many had the g92 package and the z03 heritage package(8,197 of these).

------------------
1992 Heritage Z/28
5.7 TPI
Auto Tranny
White w/red stripes
Factory Rear Window Shade
Grey Leather Interior
Alpine CD w/alpine's all around
2 12' subs in custom "camaro" box in trunk
G92 performance package w/ a/c
Flowmaster exhaust
only 14k miles on her!

[This message has been edited by 92heritageZ (edited May 30, 2001).]

 

Friend of mine has a 91 Z 305 5 speed G92 without rear disks. Its rare to see that.

 

also there were 7,106 camaros built with the g80 limited slip rear end which means some had this and not the g92 performance axle. i also find it odd that 3,645 cars had the kc4 engine oil cooler.(this being the same number of cars that had rear disks). i wonder if the two options had to be together.

------------------
1992 Heritage Z/28
5.7 TPI
Auto Tranny
White w/red stripes
Factory Rear Window Shade
Grey Leather Interior
Alpine CD w/alpine's all around
2 12' subs in custom "camaro" box in trunk
G92 performance package w/ a/c
Flowmaster exhaust
only 14k miles on her!

 

the first year for 4wdb was 1982, going by the RPO code section on my website

------------------
Webmaster: www.IROC-Z.org

 

I don't have the G92 option but I do have the J65 option on my gta if that helps thunder stick.

 

What a bag of worms we've opened, huh?
I've got the B2L, L98, GU5, G80, G92, & J65 on mine...

 

hey colin, i agree the rpo G92 shows performance axel with 3.27, and my rpo list for my 87 iroc shows G92 with GU5, 3.23 and
G80 limited slip, (i think i have a 10 bolt)
and J65 4wheel disc brks and someone else mentioned the engine oil cooler KC4, which i also have and by the way i also have the auto trans, 700R4, this can be confusing



------------------
TPIS airfoil,relocated MAT,AFPR,TB h2o bypass
March Underdrive Pulleys
otherwise stock 5.0TPI
700r4, 10 bolt 3.23 g92 axle, 4 wh. disc brks.

 

thunderstick, whats B2L mean, mine sez B4Z
i think is iroc z performance package, which includes ??



------------------
TPIS airfoil,relocated MAT,AFPR,TB h2o bypass
March Underdrive Pulleys
otherwise stock 5.0TPI
700r4, 10 bolt 3.23 g92 axle, 4 wh. disc brks.

 

on mine i have b2l, l98, gu5, g80, g92, j65, kc4, n10, and z03.

 

[/b][/QUOTE]
thunderstick, whats B2L mean, mine sez B4Z
i think is iroc z performance package, which includes ??

[/B][/QUOTE]

b2l just stands for the 5.7l 245hp tpi engine. i guess it just went with the l98 code.

------------------
1992 Heritage Z/28
5.7 TPI
Auto Tranny
White w/red stripes
Factory Rear Window Shade
Grey Leather Interior
Alpine CD w/alpine's all around
2 12' subs in custom "camaro" box in trunk
G92 performance package w/ a/c
Flowmaster exhaust
only 14k miles on her!

 

interstingly, some years of the 350 IROC used B2L AND L98... I don't knwo if they were in a changeover period or what, but I thought i'd throw that in the mix for you..

 

hey man... sounds like your car is almost identical option-wise to my '87!!

email me, I'm curious as to how close they really are maybe next time I'm in vegas we'll have to go cruising

ttyl,
Colin
Email: admin@IROC-Z.org

------------------
Webmaster: www.IROC-Z.org

 

that's all i can figure, too... I also have the kc4 & n10...

KAM

 

In 91 most G92 cars had rear disk and all 92 G92 cars do. some of the 91's did not have them because they deleated them for a short time due to the rear calapers sticking. A geat resorse for this info is "The Camaro White Book" it comes out yearly and gives all the stats for all years up to that year.

------------------
1991 Z28 ZZ4 with LPE superram base, SLP runners, LPE 58mm T-body,Random Technology ramair,TES headers,24#svo injectors,and just about every other bolt on that there is. Just got a ZEX nitrous kit!

 

stright form the tech data
*****1987******
G92 for 1987 required the following options:

5.0 TPI (LB9)
Limited slip differential (G80)
Rear disc brakes (J65)
Engine oil cooler (KC4)
G92 (performance axle ratio) available only on IROC-Z with 5.0 TPI (LB9). G92 was available on IROC-Z convertible in 1987. All 1987 350 TPI (B2L) IROC-Z's came standard with 3.27 BW rear end and thus did not have G92 code; this changed in 1988 however when a 2.77 BW rear was standard and G92 had to be specified to get the 3.27. All 1987 350 TPI (B2L) IROC-Z's required J65 rear disc brakes, G80 limited slip differential, and KC4 engine oil cooler.
-------------------
******1988******
G92(1988) (performance axle ratio) still available on IROC-Z convertible in 1988. G92 code was now available on the 350 (B2L) IROC-Z and now had to be specified to get 3.27 rear end (was standard in 1987) as a 2.77 rear was now standard on the 5.7 TPI. J65 rear disc brakes, G80 limited slip differential, and KC4 engine oil cooler were still required on all 5.7 and G92 cars.

G92(1988) option included N10 performance exhaust system (dual catalytic converters) which increased power output by 13% on cars so equipped. For 1989, G92 also required the following options:

5.7 TPI motor (B2L) or 5.0 TPI motor (LB9) with 5 speed (MM5) manual.
16 inch wheels (N96)
P245/50ZR-16 Goodyear Gatorback tires (QLC)
Limited slip differential (G80)
Rear disc brakes (J65)
Engine oil cooler (KC4)
G92 and J65 (rear disc brakes) no longer available on IROC-Z convertible.

G92 and J65 (rear disc brakes) no longer available on LB9 automatic IROC-Z.
------------
*****1989*****
Content of G92 (1989) was expanded and purchased as a `performance package' rather than requiring other options. G92 could be ordered two ways: with or without air conditioning. Ordering G92 `without air conditioning' (C41 standard heater) added the 1LE performance package. G92 performance packages were only available with B2L or LB9/5 speed. All 350 IROC-Z's were required to have one of the G92 packages in 1990.
------------------
*****1990******
G92 with air conditioning (C60):

Optional axle ratio (305/3.42, 350/3.23)
Rear disc brakes (J65)
Performance exhaust system (N10) (dual catalytic converters)
Engine oil cooler (KC4)
5.0 liter TPI (LB9) with 5 speed gets revised cam for 230hp rating.
G92 with out air conditioning (C41) in addition to above adds 1LE performance package consisting of:

Fog lamp delete
Aluminum driveshaft (JG1)
Aluminum spare wheel with smaller spare tire (N64)
Larger (11.86 inch) front rotors and PBR Australian built HD front dual piston aluminum calipers
Special swinging fuel pickup in gas tank and special 18 gallon baffled fuel tank for fuel pickup down to .5 gallon reserve to prevent fuel starvation in hard cornering
----------------
*******1991*******
G92 packages with air conditioning (C60) and without air conditioning (C41/1LE) still available on Z28. All 350 Z28's were required to have one of the G92 packages in 1991. G92 was not available on the Z28 convertible (as was the case with the previous year's IROC-Z convertible).




[This message has been edited by camaro6spd (edited May 31, 2001).]

 

Camaro...that is what was suppose to happen. Unfortunately, GM didn't always do what they were suppose to.

There are plenty of 350s in 1991 (Z-28s/GTAs) that were suppose to ALL have G92/J65, but due to problems with getting the rear disk to work with the 10 bolt rear-end many could not get the rear disk.

In which case they got EVERYTHING else except the J65 Rear Disk and G92 - Performance Axle. I have such a car, has all options (oil cooler, dual cats, aluminum drive shaft, WS6 suspension, etc)...just no rear disk and G92. When I contacted GM about this, as ALL the sales literature in 1991 said ALL GTAs had 4-wheel disks and G92 STOCK (especially if you had the L98), this is what GM explained "GM does not have enough available rear-disk rearends to option cars as described in the sales litereture. GM reserves the right to modify or alter any specification without notice or warning".

Later I found out that GM was having problems with the rear-disks with the 10 bolt rearend, so they install aluminum rear drums instead...and that is the only difference between my car (Non-G92/J42 - Aluminum Rear Drums) and a G92/J65 car.

 

On my GTA, I do not have the G92 (I'm not even sure this was an option for the GTA in '89; can't find it listed in the '89 GTA RPO codes @ GTA Source).
I do have the J65, B2L, GW6, G80, KC4. I have a few I con not find info on - UB3, D9B, U62 V73, WW6 and W62.
I also have UQ7 and this allegedly was only installed in 3 GTA's in that model year.
Weird.

------------------
"Question with boldness even the existence of a God; because, if there be one, he must more approve of the homage of reason, than that of blind-folded fear."

-Thomas Jefferson

 

89 GTA, rear vented disks, beefy rear w3.45 and World Class T5. Higher profile cam (l98 type) and NO dual cats.

------------------
89 GTA G92
305 TPI WC 5spd w/3.45
Accel Cap & 8mm Taylor's
Custom 4" Cold Air Induction
Jet Airfoil
K&N Airfilter
160 deg stat/fan switch TB Bypass - Steel Rad
Cat back 3" Exhaust w/Terminator Muff.
HiGh FlOw Dynomax Cat
Spohn LCA's - KYB GR-2's
Moroso Crank Bolt and roller pilot bearing.
New Fuel Pump!
Autometer Vac+Oil Temp
2000 Yamaha R1 150hp 385ibs

 

To answer your question about this in a simple manner, without diving into specifics is pretty simple. You're probably wondering this because of 305 5spd discussions. When people are telling you the G92 305 5spds are the hot ticket, etc, what they are referring to is the hotter 305, which means the 350 cam, dual cats, and a good bit better rear axle ratio. G92 isn't technically a package of all these parts, but to get it you had to have the others and vice versa (this is almost always the case). So in actual effect G92 was the package of all the hot stuff... Earlier G92 might not have had quite this meaning, and perhaps with some careful ordering you could get around it, but for general use on this site a G92 car is the hotter version of that engine/car package. Most times you'll see people are describing the 230hp 305 5spds. You could also get it on 350s, which also signified that the car would have dual cats (when an option) and whatever the best gears for the 350 were that year...

The 230hp 305s most definitely would not always beat the best 350 of the same year. Variances being what they are, the possibility to get a 350 w/ 2.77 gears and a single cat exhaust, different years being compared, etc makes it a fact that sometimes the 305 5spd can pull off the win...

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray


[This message has been edited by Ray87Z (edited June 01, 2001).]

 

I have the RPO (*****). What does this mean???

 

Glenn,

My 1986 Trans Am is NOT G92 but has J65 (disk brakes), G80 (posi) as well! My rear end is a F**king GH3 (Borg Warner POS 9bolt with 2.77 gears)!!



------------------
1986 Trans AM
305 TPI
Well over 200,000+ miles (speedo/odometer non-funtional! Odometer reads 142,000)
4 Wheel Discs
9 bolt Borg Warner Rear (2.77's....oh joy) :P
Completely Stock
Current Project: upgrade to a 355 TPI, 6" rods, 9.5:1 Compression, Stock TPI ported, 24#/hr LTI injectors, Hedman Shorty Headers, SBC Stock Casting heads pocket ported, Comp Cams XE262-14 TPI Cam, Ed Wright Fast Chip, Holley AFPR, TPIS airfoil, MSD wires, MSD 6-AL Box, proform hot coil!!

 

My GTA has J65 rear disc brakes and RPO's G80 and GW6 which means it has a 3.27 9-bolt posi but no G92. BTW, i thought dual cats weren't available until '89..........