Table of Contents
~~~~~~~~~~~~~~~~~
1) The GM J-Body Platform and its History
1.1) What models are currently produced on the J-body platform?
1.1.1) What are the major differences between a Cavalier and a Sunfire?
1.1.2) What are the current trim levels available on a Cavalier?
1.1.3) What are the current trim levels available on a Sunfire?
1.2) What other models have been produced on the J-body platform?
1.2.1) What trim levels used to be available on those J-bodies?
1.3) What revisions has the J-body platform been through?
1.4) Where are J-body cars produced?
1.5) What engines are currently available?
1.6) What engines are no longer available?
1.7) Has the J-body always been front-wheel-drive?
1.8) What is the top speed of a J-body?
1.9) Where can I find information on J-body specific recalls/TSB's?
1.9.1) What's with the airbag recall on 1996-97 J-bodies?
1.9.2) Early 1995 model subframe welds
1.10) The J-Body Concept Cars
1.10.1) Supercharged Sunfire
1.10.2) Cavalier Z24 Technic
1.10.3) Sunfire Speedster
2) Performance Modifications
2.1) Where do I start with modifications?
a) Will mod "x" void my warranty?
2.2) What companies are out there that make mods for the J-body twins?
2.4) The Engine
2.4.1) Stock performance information
2.4.2) Do they make Splitfire/Rapidfire plugs for my engine?
2.4.3) What about upgrading the chip/ECU?
a) Where is the computer located?
2.4.4) Is there a "Power Programmer" device available for the
Cavalier/Sunfire?
2.4.5) Has anyone (other than the factory) ever supercharged or
turbocharged their J-body?
2.4.6) What about adding NOS?
2.4.7) Does synthetic oil make a difference?
2.4.8) The Throttle Body
2.4.9) Cold Air Intake
2.4.10) SpiralMax
2.4.11) "RAM AIR" Hood / Ram Air-type modifications
2.4.12) The IAT Sensor
2.5) The Exhaust System
2.5.1) For a performance exhaust, what are the ideal specs?
2.5.2) What muffler brand is best?
2.5.3) Should I gut out (or remove) my catalytic converter?
2.5.4) The tuner tube
2.5.5) The resonator
2.5.6) The header
2.6) The Suspension
2.6.1) Who makes upgraded springs/struts for the J-body?
2.6.2) I installed Eibach springs on my car. Now the ride is really
harsh/bouncy. Why?
2.6.3) What is a strut tower bar?
a) Why wasn't one included on all the 3rd Gen J-body models?
b) Where can I get one? What is the part #?
2.6.4) What is that "loose lumber" sound coming from my trunk?
2.6.5) What is a rear anti-sway bar?
2.7) Wheels and Tires
2.7.1) What tires should I buy?
a) What brand?
b) What type?
c) What are the trade-offs?
2.7.2) What is the bolt pattern for custom rims?
2.7.3) What is the offset for custom rims?
2.7.4) What size rims will fit?
2.7.5) How wide can my tires be before they start to rub on the
wheelwells?
2.8) Appearance
2.8.1) Who makes body-cladding kits for Cavalier/Sunfire/Sunbird?
2.8.2) Can I upgrade my headlights?
2.8.3) What are "Blue Ion" bulbs?
a) Are they legal?
2.8.4) Can I upgrade the fog lights on my 95+ Cavalier/Sunfire?
2.8.5) Window Tinting
a) How do I get the little "dots" off the rear window to tint it?
b) What's the legal % limit to window tint?
2.8.6) Where can I get a "Ram Air" Hood like the Supercharged Sunfire/
Cavalier Technic?
2.9) The Transmission
2.9.1) Who makes the transmission on J-body cars?
2.9.2) Is there synthetic oil that's compatible with my transmission?
2.9.3) Stock gear ratios - 5-spd and Auto
a) 1st Gen
b) 2nd Gen
c) 3rd Gen
2.9.4) The 5-speed Shifter
a) How do I shorten my shifter?
b) Can I change the knob on my shifter?
2.9.5) How much torque can the stock transmissions take?
2.10) The Clutch
2.10.1) Who makes upgraded clutches for the J-body?
2.11) Brakes
2.11.1) Are upgraded brakes available for the J-body?
2.11.2) Is there any way to convert my rear drums to rear discs?
2.11.3) What about cross-drilled or slotted rotors?
2.11.4) How many times can I "turn" the rotors before I should replace
them?
2.11.5) What is the average number of miles a set of brakes on the
3rd Gen J-body last?
2.11.6) When I upgrade my pads, should I use carbon-metallics?
2.11.7) What is that high-pitched "squealing" noise my brakes make...
a) When braking?
b) When I turn the wheel one way or the other while driving?
c) Until I apply the brakes?
3) Decoding your J-body's VIN Number
==========================================================================
1) The GM J-Body Platform and its history
==========================================================================
---------------------------------------------------------------
1.1) What models are currently produced on the J-body platform?
---------------------------------------------------------------
Currently, the Chevrolet Cavalier and Pontiac Sunfire.
---------------------------------------------------------------------
1.1.1) What are the major differences between a Cavalier and a Sunfire?
---------------------------------------------------------------------
Exterior styling and some minor interior styling. The base mechanicals
remain the same for both cars, and both cars have essentially the
same equipment available. To GM, the Cavalier is positioned as the
more "value-based" car, while the Sunfire is seen as the more
"performance-based" car. It is because of this that the Sunfire
receives things such as more sound-deadening material and thicker
padding in the dash and seats. According to a list memeber who works
at the Lordstown plant, the Sunfire also receives slightly
higher-quality materials than the Cavalier.
Also, the Sunfire GT receives a dual-muffler exhaust system, while
the Z24 does not.
----------------------------------------------------------------
1.1.2) What are the current trim levels available on a Cavalier?
----------------------------------------------------------------
The Cavalier is available as a coupe in base, RS, Z24, and Z24
Convertibles. It is also available as a sedan in base and LS.
---------------------------------------------------------------
1.1.3) What are the current trim levels available on a Sunfire?
---------------------------------------------------------------
The Sunfire coupe is available in SE, GT, and SE Convertible
models. The Sunfire sedan is only available in SE form.
-----------------------------------------------------------------
1.2) What other models have been produced on the J-body platform?
-----------------------------------------------------------------
1982 Pontiac J2000 (no dash, slash, hyphen, space, or anything)
1983 Pontiac 2000 and 2000 Sunbird Convertible
1984 Pontiac 2000 Sunbird
1985-94 Pontiac Sunbird
1982-88 Oldsmobile Firenza
1982-89 Buick SkyHawk
1982 Cimarron by Cadillac, 1983-88 Cadillac Cimarron
1982-94 Chevrolet Cavalier (was almost called Corsair!)
An interesting side note about the J-body:
Cavalier and 2000 Sunbird convertibles first appeared in 1983 in
quantities limited to 627 units each produced by American Sunroof in
Michigan. No other division ever released a J-body convertible.
It is also an interesting note (no offense to Cimmaron fans) that the
Cimmaron is considered the WORST J-car of the series, based upon its
styling compared to the Cavalier and its comparatively exorbitant price.
---------------------------------------------------------------
1.2.1) What trim levels used to be available on those J-bodies?
---------------------------------------------------------------
Cavalier has been offered in an extremely wide variety of models and
trim-line designations. For example: RS, LS, Z24, Type-10, CL, VL, CS,
and CX that designated major performance equipment and options.
The Cavalier was introduced as an early '82 model on March 21, 1981.
J2000 and Cimarron joined immediately while SkyHawk and Firenza waited
until a few months later.
In 1984, 5181 Cavaliers are reported to have been made with the Special
Olympic Appearance package.
The Cavalier wagon and J2000 Safari were available by the end of the '82
model year while SkyHawk wagon and Firenza Cruiser were not produced
until the '83 model year. Firenza Cruiser (as well as the Firenza itself)
and Sunbird Safari were cut after the 1988 year, SkyHawk hung on for one
more, and Cavalier wagon stayed on the list until the 1995 redesign.
Cavalier has also appeared (unofficially) with GT, SS, and Z22 that were
dealer-applied graphics and/or interior equipment packages.
Type-10 was the forerunner to what was called RS after 1985. You can
notice a direct relationship in appearance as thr '84-85 Type-10 and
'86-90 RS both had regular-style grilles in black where the lower-level
models had either silver or body-colour grilles depending on the year. It
was also a predecessor of the Z24.
*****> What was CL in '86-87?
The Cavalier Z24 first appeared as a 1986.5 model year car. Only a very
limited number were produced. They can be picked out by the "Z24" logos
and ground effects, along with the steel wheels (unlike the aluminum
alloys used in the 1987+ model years). It was available in 2-door (coupe)
and 3-door (hatchback) forms both in '86 and '87. Z24's from 1986-1990 had
a specially designed grille in black.
In 1988-1990, the VL was an upscale base (only a few select options).
In 1989, although there was no RS there was an RS trim package for the
base and VL sedans which consisted of the wheels (which were also
available as a seperate option) and the body side moldings.
In 1990, a CX and CX Sport model were created, although it is rumored that
a few 1991 or later ones exist. The 1990 version has CX Sport written
just under the taillights within a long black strip. The 1991 version has
a side decal on the underside of the door.
The Cavalier VL that first appeared in 1992 and remained until the new gen
Cavalier was introduced in 1995 had only one side mirror and one black
molding stripe down the sides, in addition to the standard pinstripe.
They have power locks, power steering, power brakes, and a 2.2L automatic.
Some later models of the VL appear with a second side mirror.
ABS became standard equipment on the J-body in 1992.
Cavalier and Sunbird hold the extremely rare distinction of being
available as a 2-door, a 3-door, a 4-door, a 5-door, and a convertible
in the same years from 1983 to 1987!
SkyHawk and Firenza were available in all but convertible, and Cimarron
was only available as a 4-door sedan.
---------------------------------------------------------
1.3) What revisions has the J-body platform been through?
---------------------------------------------------------
The J-body is currently in its third generation. This generation started
in 1995 with the introduction of an all-new Cavalier and Sunfire.
There was a "freshening" of the second generation J-body in 1991, so
some enthusiasts call the period from 1991-1994 "Generation 2.5" because
the changes to the car were fairly significant:
* The front and rear fascias were changed to their 1992 appearance.
* The interior was also changed to 1992 configuration.
* The two tone paint scheme was dropped in 1991 in favor of a single
color for both the ground effects and body.
* The luggage rack was still available on the Z24.
* In 1992 the decklid luggage rack was dropped in favor of the wing seen
on 1992-1994 models.
* ABS first appeared as a standard feature.
Officially, however, I recognize the following generations:
3rd Generation: 1995-present
2nd Generation: 1988-1994
1st Generation: 1983-1987
Another J-body historian offers a different view:
The actual J-body itself is divided into 2 generations: 1982-94 and
1995-present, but the coupe and convertible underwent massive
streamlining in the rear quarter and all models underwent major
front-end revision for the 1988 model year, setting 1988-94 apart in the
two-door models as a sort of generation of its own. The 3-door
hatchback was dropped with this revision, and the sedan and wagon
remained virtually unchanged from the radiator back until the mass
redesign for 1995, where the wagon was dropped and the coupe,
convertible, and sedan received major changes in the front end frame,
suspension, body shape, and performance options. The floorpan and basic
frame save for the front end and suspension systems are virtually the
same.
------------------------------------
1.4) Where are J-body cars produced?
------------------------------------
Lordstown, Ohio
Lansing, Michigan
Coahuila, Mexico
Janesville, Wisconsin
------------------------------------------
1.5) What engines are currently available?
------------------------------------------
The standard GM 2.2L inline-4 cylinder OHV engine, and the 2.4L LD9
"Twin Cam" inline-4 cylinder DOHC engine.
------------------------------------------
1.6) What engines are no longer available?
------------------------------------------
1.8L inline-4 OHV
1.8L inline-4 SOHC
1.8L inline-4 SOHC Turbo (84-87)
2.0L inline-4 OHV (Cavalier-specific)
2.0L inline-4 SOHC
2.0L inline-4 SOHC Turbo (87-1990 Sunbird Turbo)
2.3L inline-4 DOHC "Quad 4"
2.8L V-6 MPFI
3.1L V-6 MPFI
--------------------------------------------------
1.7) Has the J-body always been front-wheel-drive?
--------------------------------------------------
Yes. The original purpose in the J-car project was to produce a
front-wheel-drive replacement to the rear-wheel-drive H-car (Monza,
Sunbird, Starfire, SkyHawk) and follow-up to the X-car project
(Citation, Phoenix, Omega, Skylark) released two years earlier.
Yes, the Sunbird name has been used on more than just the J-body car.
Here's a quick breakdown for you:
RWD H-Car FWD J-Body Replacement
~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~
Chevrolet Monza & Monza Spyder Chevrolet Cavalier
Pontiac Sunbird & Sunbird Formula Pontiac 2000/2000/2000 Sunbird/
Sunbird/Sunfire
Olds Starfire & Starfire Firenza Olds Firenza
Buick SkyHawk Buick SkyHawk
------------------ Cadillac Cimarron
---------------------------------------
1.8) What is the top speed of a J-body?
---------------------------------------
This is a subject of great debate. The current models have both a
speed governor and a rev limiter. It can be agreed that most members'
(stock) cars top out between 108-114 mph (172.8-182.4 km/h).
-------------------------------------------------------------------
1.9) Where can I find information on J-body specific recalls/TSB's?
-------------------------------------------------------------------
Try http://www.nhtsa.dot.gov or http://www.alldata.com.
---------------------------------------------------------
1.9.1) What's with the airbag recall on 1996-97 J-bodies?
---------------------------------------------------------
Not much information has been made available to us about how or why this
has happened, but in the official GM recall announcement, it says that the
airbag control module used in 1996 and 1997 J-bodies needs to be
reprogrammed. Apparently, if an object strikes the floorpan just right, it
can cause the airbags to go off. I read somewhere (I don't remember where)
that there were over 300 reported incidents of this happening. So, if you
have a 1996 or 1997 J-body and have not received the letter describing the
problem and how to get it remedied, check with your local dealer to see if
your car is affected and if so, if the problem has already been remedied.
--------------------------------------
1.9.2) Early 1995 model subframe welds
--------------------------------------
Some early 1995 model J-body cars were missing a weld on the lower A-arm
assembly, causing it to break and the driver to lose control of their car.
Luckily, GM found the problem early, and dealers were instructed where to
properly spot-weld to fix the problem. To give you an idea of how few
J-bodies were affected by this, my car was one of the first 3000 3rd Gen
J-body cars, and it had already been fixed before my car even got to the
dealership. However, if you have a '95, you should check with your local
dealer to make sure that the fix has been made (or wasn't necessary).
==========================================================================
2) Performance Modifications
==========================================================================
-----------------------------------------
2.1) Where do I start with modifications?
-----------------------------------------
This depends mostly on your budget. A good first place to start is with
the intake system. K&N makes a drop-in filter that replaces the stock
air filter in the black box/canister for all models except the 1988-90
2.0L Inline-4. The part number for 1982-1987 TBI 4 cylinder engines is
E-1015. You can reach K&N at http://www.knfilters.com.
If that doesn't give you more pep, you can always replace the stock air
box/canister with a cold-air intake system as described below and outlined
on http://www.z24.com. Some members on the list have even fashioned their
own cold-air intakes.
Another large performance gain can be had by simply replacing the stock
exhaust system with a new one. See the exhaust section below for more
details.
---------------------------------
a) Will mod "x" void my warranty?
---------------------------------
No dealer can "void" the whole car's warranty. If you modify a stock
part, of course it won't be under warranty anymore. If you modify (or
remove) your stock airbox, it will no longer be under warranty. However,
the dealer can not void the warranty of anything else "down the line"
from the mod that you installed.
For instance, if you replace your stock airbox with a high-flow intake
with a K&N Filtercharger cone filter, the dealer can't void the warranty
on your throttle body, O2 sensor, or intake manifold.
Of course, there will always be exceptions to the rule. You may want to
check with your dealer before you do a mod, just to be safe. If you
REALLY want to be safe, wait until your car has hit 3 years or 36,000
miles. Then everything's free reign!
For more information on what to do if the dealership refuses to honor
your warranty, contact SEMA. If you have installed a reputable
aftermarket part, SEMA will help you get that warranty issue taken care
of. You can also check out Philip Greenspun's interesting article at:
http://photo.net/philg/litigation/automobile-disputes.html. He also has
another interesting article at http://photo.net/philg/litigation/smyly/.
For information on the Magnuson-Moss Warranty Act, visit:
http://www.ftc.gov/bcp/conline/pubs/buspubs/warranty/toc.htm
----------------------------------------------------------------------
2.2) What companies are out there that make mods for the J-body twins?
----------------------------------------------------------------------
Mantaparts
*****> need snail-mail address and phone #
mantapart@aol.com
RKSport
Website: http://www.rksport.com
E-Mail: rksport@aol.com
rksport@earthlink.net
Address: 214 Via El Centro, Oceanside, CA 92054
Fax: (760)433-1477
Order Phone# (800)214-8030
Tech Phone# (760)433-1664
===============
2.4) The Engine
===============
------------------------------------
2.4.1) Stock performance information
------------------------------------
*****> Hey, I need some help with this section.. Any of you with old mags
*****> please consult them for these specs... thanks!
Performance numbers are for the 5-speed. Automatics may differ.
|2.4 I-4 |2.3 I-4 |2.2* I-4 |2.2** I-4 |
--------------------+-----------+-----------+-----------+-----------|
HP @ rpm |150 @ 5600 |150 @ xxxx |120 @ 5250 |115 @ xxxx |
Torque @ rpm |155 @ 4250 |145 @ xxxx |130 @ 4000 |135 @ xxxx |
0-60 mph | | | | |
1/4 mile | | | | |
--------------------+-----------+-----------+-----------+-----------+
* 1995-1997 Models
** 1998+ Models
|2.0T I-4 |2.0 I-4 |1.8 I-4 |1.8T I-4 |
--------------------+-----------+-----------+-----------+-----------|
HP @ rpm |xxx @ xxxx |xxx @ xxxx | 84 @ xxxx |xxx @ xxxx |
Torque @ rpm |xxx @ xxxx |xxx @ xxxx |108 @ 3800 |xxx @ xxxx |
0-60 mph | | | | |
1/4 mile | | | | |
--------------------+-----------+-----------+-----------+-----------+
|2.8 V6 |3.1 V6 |
--------------------+-----------+-----------|
HP @ rpm |120 @ xxxx |140 @ 4200 |
Torque @ rpm |185 @ 4000 |185 @ 3400 |
0-60 mph | | |
1/4 mile | | |
--------------------+-----------+-----------+
------------------------------------------------------------
2.4.2) Do they make Splitfire/Rapidfire plugs for my engine?
------------------------------------------------------------
Splitfires have come under deep scrutiny in recent days. Their
overall effectiveness is in doubt. A model was available to fit the
2.8L V6. I know, because I had a set. I thought I could feel a slight
increase in power, but it may have been because the engine had 70,000
miles on the stock plugs (they had never been changed).
Rapidfire plugs, however, are available for the 2.4L "Twin Cam" engine.
You need plug #6, available from your local Wal-Mart or possibly any local
automotive performance store. If you have the 2.2L engine, you're out of
luck. GM has not released Rapidfire plugs compatible with our engine yet.
Mailing list members have had good results replacing their stock plugs
with the Rapidfire plugs. However, the 3rd Gen J-body cars all come with
100,000 mile Platinum spark plugs, so you may want to think twice before
changing plugs.
-----------------------------------------
2.4.3) What about upgrading the chip/ECU?
-----------------------------------------
Because of OBD-II restrictions, all models after the 1995 model year
require a complete ECU upgrade. 1995 and older models can replace just
the chip in the computer.
--------------------
a) Where is the ECU?
--------------------
The ECU is located either beneath the driver's seat, underneath the
dash on the passenger's side, or in the glove box. It is that
rectangular silver box that has a jumble of wires coming out of it.
Some 95 Sunfires have the computer in the right fender.
-------------------------------------------------------------
2.4.4) Is there a "Power Programmer" device available for the
Cavalier/Sunfire?
-------------------------------------------------------------
Not yet, but one is rumored to be in development.
-----------------------------------------------------------------
2.4.5) Has anyone (other than the factory) ever supercharged or
turbocharged their J-body?
-----------------------------------------------------------------
I'm sure at least someone out there has done this to their J-body.
Unfortunately, no one on the list has done something this drastic
yet. Part of the problem with adding a turbo/supercharger onto the
LD9 engine is that it would require recalibration to get the timing
right. It would also force you to reprogram the computer for the
higher compression ratio, and to compensate for the lean burning
condition (too much air) by adding more fuel into the cylinder.
Additionally, turbos and superchargers can cause enough pressure in
the cylinders to cause the pistons, valves, bearings, or other
internal components to explode or damage themselves badly.
The Sunbird GT Turbo engines were notoriously bad for head gasket leaks,
turbo failures, and other such problems, even after only 20,000-30,000
miles. Required mainainance on this engine is high. That's why GM
discontinued the engine.
-----------------------------
2.4.6) What about adding NOS?
-----------------------------
In my opinion, the J-body does not take well to a NOS system. This does not
mean I'm against NOS altogether, and I'm sure there are some applications in
which it works very well. However, I feel that the extra strain that the
NOS puts on the engine (especially in improper installations or excessive
use) will certainly cause parts to "expire" prematurely. One particular
member of the mailing list tried NOS on his 2.4L engine once. After it
completely blew up, forcing him to replace the engine, he decided that there
were other "gearhead" means of providing performance without NOS.
--------------------------------------------
2.4.7) Does synthetic oil make a difference?
--------------------------------------------
Honestly, I'm not sure anyone can say. Arguments can be made both for dead
dinosaur juice and techno-lube. I personally prefer Castrol Syntec. I
think it makes the engine run more smoothly at idle and reduces wear and
tear on the engine. Most members of the list agree that once you choose an
oil that you should stick with it. Mobil 1 is another frequently-used
synthetic.
------------------------
2.4.8) The Throttle Body
------------------------
The stock GM throttle for a 2.4L engine is 46mm. Basically, the theory
behind boring out your throttle body is that the more air you can get to the
engine, the more power it will produce. Mantapart makes a 56mm overbored
throttle body for the J-body cars. This is one of the more common
performance mods made to the J-body, since it's a simple and straightforward
replacement of the stock unit with the new one. Unplug the battery for
15-20 minutes to reset the computer (so it won't run lean with all that
extra air), and your new TB should be good to go! See http://www.z24.com
for more information on this mod.
----------------------
2.4.9) Cold Air Intake
----------------------
The cold air intake is also one of the most common J-body modifications. It
constitutes removal of the stock air box (and sometimes the entire S-hose)
and replacement with a special smooth plastic tube and a conical K&N
Filtercharger on the end. Some extreme 3rd gen modifiers have applications
of this modification that actually extend the tube into the front driver's
side fender (just behind the wheelwell), with part of the wheelwell cover
removed (and replaced with a wire mesh) to provide a small "RAM AIR" effect.
See http://www.z24.com for more detailed information on this mod.
-----------------
2.4.10) SpiralMax
-----------------
Visit http://www.spiralmax.com and decide for yourself. I have one unit
installed in my 2.2L engine, and I immediately felt a difference. However,
other members of the list don't feel this is worth the money. Like I said
before, I'm not a "gearhead," so I'm going for the simple, quick, easy mods.
---------------------------------------------------
2.4.11) "RAM AIR" Hood / Ram Air-type modifications
---------------------------------------------------
As discussed in 2.4.9, the cold-air intake in the front fender works well
for the 3rd gen J-body cars. There are currently no functional "RAM AIR"
replacement hoods being produced for the J-body twins, but I imagine that
some company will come out with a mass-produced replacement hood for the
J-body twins.
----------------------
2.4.12) The IAT Sensor
----------------------
IAT=Incoming Air Sensor. This modification takes the IAT sensor and
moves it somewhere else in the car (usually the grille or replacement
cold-air intake system). The theory behind moving the IAT is to trick
the computer into thinking that the air the engine is receiving is colder
(denser) than it really is, causing the computer to add more fuel to the
mixture. Sure, it makes your engine run just a bit richer, but there's a
1-2hp gain to be had here. It is also a good preliminary mod to make to the
car if you plan on making more performance mods to the car after you've
tinkered with it a bit. Again, visit http://www.z24.com for more info
on the IAT modification.
=======================
2.5) The Exhaust System
=======================
-----------------------------------------------------------
2.5.1) For a performance exhaust, what are the ideal specs?
-----------------------------------------------------------
Dyno testing has shown that 2.25" mandrel-bent piping provides the best
balance of horsepower, torque, and backpressure necessary for a 3rd gen
J-body. The older V6 engines may be different.
*****> What about those V6 engines? Do we have any dyno results for
exhaust systems on the older gen cars?
----------------------------------
2.5.2) What muffler brand is best?
----------------------------------
Again, dyno testing has shown that Imco mufflers provide a superior
torque curve, even to those of the Flowmaster and Dynomax Super Turbo.
The full dyno test results are available on http://www.z24.com.
-----------------------------------------------------------
2.5.3) Should I gut out (or remove) my catalytic converter?
-----------------------------------------------------------
NO! You can get pegged with a fine and jail time for removing or
tampering with an emissions control device. You would contribute even more
pollution to our environment by not having a catalytic converter. Your
car will not pass emissions/inspection without a catalytic converter. In
fact, the 3rd gen J-body (both 2.2L and 2.4L) do not perform well without
at least some of the backpressure that a catalytic converter adds.
Your only option here is to replace your existing converter with a high-
flow cat, like the one available from Dynomax.
---------------------
2.5.4) The tuner tube
---------------------
On the LD9, there is a little plastic tube that sits inside the ugly black
box that is right in front of the engine. It is meant to smooth out the
airflow, in order to quiet the engine. It works well, but robs the engine
of precious air. Removing this device can help both peak horsepower and
torque. For full removal details, see http://www.z24.com.
--------------------
2.5.5) The resonator
--------------------
The resonator is another restricting device meant to help tune the exhaust
note. It is added directly after the catalytic converter. It looks like
this:
-----------
\----------------------
>>From cat > To muffler
/----------------------
-----------
When you have your custom exhaust or muffler installed, have the mechanic
remove the resonator for you. You will notice a power gain because the
exhaust is now more free-flowing than before.
-----------------
2.5.6) The header
-----------------
Headers are the pipes that go from the exhaust manifold to the downpipe
leading to your catalytic converter. Aftermarket headers are usually less
restrictive than stock, providing better exhaust flow. Obviously, exhaust
is hot, so special ceramic-coated headers are available to help keep the
heat in the engine compartment down, allowing cooler air into the engine.
Cooler air=more power, so ceramic-coated is a good way to go.
There have been quality concerns with RK Sport's headers for the 2.4L
engine. We recommend looking elsewhere (Mantapart, Force Induction Systems)
for your headers.
===================
2.6) The Suspension
===================
--------------------------------------------------------
2.6.1) Who makes upgraded springs/struts for the J-body?
--------------------------------------------------------
Eibach is by far the most-installed spring on enthusiasts' J-body cars.
Mantaparts also makes a spring/strut upgrade for the J-body cars. Tim
claims much better performance than stock, and many members on the list
will back him up. His struts are specially built and come paired with
Eibach springs ready to install.
Struts come in many flavors. Check with your friends and other
enthusiasts for stories and testimonials on these. They're almost as
subjective as tires. As far as I know, there is no "standardized"
testing done on struts, so I can't say that one brand is better than
another.
--------------------------------------------------------------------
2.6.2) I installed Eibach springs on my car. Now the ride is really
harsh/bouncy. Why?
--------------------------------------------------------------------
If you didn't change the struts along with the springs, you're going to
notice why suspensions are all specially tuned at the factory. The
stock struts are not meant to dampen the kind of shock they are now
receiving due to the stiffer springs. They just can't handle the extra
stresses, so they bottom out, don't rebound fast enough, and just
underperform. You can remedy the situation by purchasing new struts.
---------------------------------
2.6.3) What is a strut tower bar?
---------------------------------
The strut tower bar is a special piece of hardware that connects the two
strut towers underneath the hood to each other, and to the firewall. It
is meant to better distribute the forces of cornering and to control
chassis torsion (a "twisting" of the frame) for a smoother turn. It also
reduces that "hop" that you can experience when turning and going over an
expansion joint on the road at the same time.
It is currently only available (stock) on the convertible J-body cars.
------------------------------------------------------------
a) Why wasn't one included on all the 3rd Gen J-body models?
------------------------------------------------------------
GM must've decided that the convertible models were the only ones that
would benefit from the strut tower bar, because of the lessened chassis
rigidity and structural integrity that results when you chop the roof off
of a car. However, they didn't take into consideration enthusiasts like
you or me. Luckily, a strut tower bar fits just fine on all the J-body
models.
--------------------------------------------
b) Where can I get one? What is the part #?
--------------------------------------------
From your local dealership. One of the part numbers for a '98 J-body is
22604347. It is listed in the computer simply as "Brace". For the '96-97,
try 22642387. Be sure to check with your dealer, because there are
different part numbers for each model year, and whether or not your car
has cruise control.
Aftermarket bars also exist. One is made by Freedom Design. It is
polished forged aluminum, and it costs about $100. Part #63102.
Mantapart also has a strut tower bar (both front and rear), and a
lower subframe brace, all of which contribute to rigidity and increase
structural integrity.
RK Sport's strut tower bar is under $100.
--------------------------------------------------------------
2.6.4) What is that "loose lumber" sound coming from my trunk?
--------------------------------------------------------------
Some 1996 and 1997 model year J-body cars had this sound. It came from
a bad strut mount on the rear suspension. GM has issued a technical
service bulletin on this issue. If your car is experiencing this problem,
GM will replace those parts under warranty.
------------------------------------
2.6.5) What is a rear anti-sway bar?
------------------------------------
Compared to the upper strut tower bar, which is designed to increase
structural rigidity, the rear sway bar is designed to prevent body roll
from occuring in corners. This reduction of body roll prevents the
transfer of weight to the outside edge of your car which can "throw"
the rear end outward in a curve (a.k.a. "spinout").
The rear anti-sway bar attaches externally to your rear axle through four
mounting points. The bar sits directly underneath the rear axle, and
mounts in two spots to the axle using polyurethane bushings and bolts on
each of the mounts. The bar then curves 90 degrees on each side and
curves towards the back of the car. The other two mounts attach to the
rear spindle assembly near the rear brake drums with a special bracket
included with the RK Sport kit.
Anti-sway bars also exist for the front axle of the car. You must be
careful when adding these bars, because if the bar is too large in either
the front or the rear, you will introduce either understeer or oversteer.
The trick is to find a balance, or "neutral" handling condition, where the
car neither "pulls" you inward through the turn nor "pushes" you outward
through the turn. Oversteer (or "pulling") is mostly found on rear wheel
drive cars, like the F-body. Understeer (or "pushing") is mostly found on
front wheel drive cars, like the J-body.
The RK Sport 19mm rear anti-sway bar, made by Hellwig, seems to help
create a more "neutral" handling when added to the J-body, while keeping
your stock front sway bar. The kit, item #CAV-3875, is $145.00.
ADDCO makes 25mm rear anti-sway bars for the J-body. They are $185.00.
More info is available on their website at:
http://www.addcoindustries.com/addco.shtml
JC Whitney sells Hellwig rear anti-sway bars, but for $95.00.
IMPORTANT: Members of the list recommend that you keep your front anti-sway
bar stock, because adding a larger front anti-sway bar will worsen the
natural understeer of the J-body.
=====================
2.7) Wheels and Tires
=====================
-------------------------------
2.7.1) What tires should I buy?
-------------------------------
The 3rd Gen J-bodies come stock with:
P195/70R14 (hubcaps)
P195/65R15 (hubcaps or mags)
P205/55R16 (GT/Z24 mags)
The 2nd Gen J-bodies came stock with:
P205/60R15 (aluminum rims)
*****> What about first and other second gen wheel/tire combos??
--------------
a) What brand?
--------------
Pick your favorite brand, and buy away. Some people buy for value, some
buy for performance, some buy for tread pattern or width. Tires are a
very subjective item to buy, so I cannot recommend any one brand over
another.
List members seem to be pleased with Michelin, BFGoodrich, Dunlop,
Pirelli, Nitto, and Goodyear.
-------------
b) What type?
-------------
Depending on your local conditions, you may want to consider M+S (Mud +
Snow) tires, or you could go for touring tires, rain-gutter tires, or
high-performance tires. You may want to talk with someone at one of the
large national phone-order tire chains in order to get a better idea of
which tires are best suited for you.
---------------------------
c) What are the trade-offs?
---------------------------
* Ride conditions (harsher/softer)
* Handling (grip in corners)
* Traction (some tire compounds are "stickier" than others)
* Speedometer re-calibration (if you don't use a Plus-1 or Plus-2 size).
------------------------------------------------
2.7.2) What is the bolt pattern for custom rims?
------------------------------------------------
5x100
------------------------------------------
2.7.3) What is the offset for custom rims?
------------------------------------------
48mm, but 46-48mm offsets will work. Some people have installed 35mm
offset rims, but they stick out of the wheel wells more than stock.
Remember that the wrong offset wears the tires faster, and can cause
rubbing and handling problems. In some cases even the suspension will
wear faster than normal.
-------------------------------
2.7.4) What size rims will fit?
-------------------------------
Some list members have installed up to 16x7 rims and 205/55R16 tires.
Even though the stock rims are only 6" wide, 7" will fit comfortably.
These specs are for the third-gen cars, the older gen cars could handle
up to 225/50R15 tires.
---------------------------------------------------------------
2.7.5) How wide can my tires be before they start to rub on the
wheelwells?
---------------------------------------------------------------
If you go larger than a "Plus-1" or "Plus-2" size, your tires will most
likely rub. A "Plus-1" size is increasing the diameter of the tire one
inch, increasing the width of the tire 10mm, and decreasing the height of
the tire 10mm. For instance, if you started with P195/65R-15 tires, you
could change them to P205/55R-16 and they should fit. A "Plus-2" does
this twice. So, if you started with the same tire above, you could
change them to P215/45R-17's. These might have a better chance of
rubbing, though, because a 215mm wide tire is a lot larger than stock.
The actual contact patch of the tire with the "Plus-2" size, however,
would be MUCH larger than stock... Nice for corners, maybe not so nice
for bumps.
===============
2.8) Appearance
===============
-----------------------------------------------------------------
2.8.1) Who makes body-cladding kits for Cavalier/Sunfire/Sunbird?
-----------------------------------------------------------------
There are several manufacturers, but the only one that comes to mind is
RK Sport (http://www.rksport.com).
-----------------------------------
2.8.2) Can I upgrade my headlights?
-----------------------------------
Yes and no. The current gen Sunfire uses bulb #9007 for both high and low
beams. The Cavaliers have two bulbs per headlight assembly -- #9006 and
#9007. They are currently 55W/65W (low/high) bulbs.
There are stores that sell 80W/100W #9007 bulbs, but list members who have
used these bulbs find that the wire harnesses are not built to consistently
take that kind of wattage and have melted, forcing their replacement.
Upgraded harnesses are available to allow your car to safely use the 80/100
bulbs.
Technically, these bulbs are illegal for street cars, but they are commonly
used on police cruisers for better illumination (ever wonder why a cop's
headlights are so much brighter than yours?). Some people believe that if
the cops can use them, so can we. Caveat emptor.
---------------------------------
2.8.3) What are "Blue Ion" bulbs?
---------------------------------
Some people mistake these "Blue Ion" bulbs for those special illumination
systems seen in the newer Lincoln Mark VIII cars, BMW 7-series, and Mercedes
E-Class cars. They are not. The technology used in these cars is called
High Intensity Discharge (HID). HID systems use an arc of pure white light
within a Xenon-filled bulb to produce the clean, bluish-white light you see.
The "Blue Ion" bulbs are supposed to make your #9007 bulbs look similar to
these HID systems. The manufacturers take a standard #9007 bulb, dip it in
some blue dye, and sell them as "Blue Ion" bulbs. Unfortunately, since
these bulbs are now dyed, they put out less light per watt than a similar
clear bulb. Once again, caveat emptor.
------------------
a) Are they legal?
------------------
In some states, they are not. Highway Patrol officers have been known to
pull cars over to warn drivers that their bulbs are either too dim, or
colored. Laws are in place that state that headlights must be white light,
so if your headlights were colored red, yellow, blue, green, or any other
color, you could be cited. Check with your local Highway Patrol to find
out if you're going to be pulled over if you add these bulbs to your car.
Note that these rules only apply to HEADLIGHTS, not FOG LIGHTS. Fog lights
are commonly yellow, and sometimes blue... Wavelengths of light that help
cut down on reflected light when moisture is in the air (fog, snow, rain,
etc.).
---------------------------------------------------------------
2.8.4) Can I upgrade the fog lights on my 95+ Cavalier/Sunfire?
---------------------------------------------------------------
Yes. The stock fog lights are 37.5 Watt #881 bulbs. You can replace them
with #886 55 Watt bulbs.
---------------------
2.8.5) Window Tinting
---------------------
-----------------------------------------------------------------
a) How do I get the little "dots" off the rear window to tint it?
-----------------------------------------------------------------
There have been several methods suggested on the mailing list, from using
razor blades to scratch them off to using commercial-grade acids. Some
members didn't have to remove the dots to get their tint to settle
properly. I suggest that you let a professional tinting shop take care
of this for you.
-------------------------------------------
b) What's the legal % limit to window tint?
-------------------------------------------
This varies from state to state. Check with your local Highway Patrol to
find out what percent is legal in your state.
----------------------------------------------------------------------
2.8.6) Where can I get a "Ram Air" Hood like the Supercharged Sunfire/
Cavalier Technic?
----------------------------------------------------------------------
There is currently no "Ram Air" hood commercially available for the
J-body twins. There are several rumored to be in development, and one
that is close to being available from RK Sport. According to RK Sport,
the replacement hood will cost in the neighborhood of $700. Check
their website for more detailed and up-to-date information.
=====================
2.9) The Transmission
=====================
-------------------------------------------------
2.9.1) Who makes the transmission on J-body cars?
-------------------------------------------------
Isuzu
---------------------------------------------------------------------
2.9.2) Is there synthetic oil that's compatible with my transmission?
---------------------------------------------------------------------
Yes. Redline MTL Fluid is a great choice. Visit http://www.redlineoil.com/
for more information.
-----------------------------------------
2.9.3) Stock gear ratios - 5-spd and Auto
-----------------------------------------
*****> Help! Does anyone have any shop manuals with this info in them?
----------
a) 1st Gen
----------
----------
b) 2nd Gen
----------
----------
c) 3rd Gen
----------
--------------------------
2.9.4) The 5-speed Shifter
--------------------------
-------------------------------
a) How do I shorten my shifter?
-------------------------------
Take off the knob, then use a dremel cutting wheel to trim it down. See
http://www.z24.com for step-by-step instructions on how to do this
properly.
---------------------------------------
b) Can I change the knob on my shifter?
---------------------------------------
Yes. Just pop out the U-shaped clip from the front of the knob. The old
knob should slide right off the shaft.
--------------------------------------------------------
2.9.5) How much torque can the stock transmissions take?
--------------------------------------------------------
Extreme 3rd gen modifications have placed the max stress point at around
190hp and 200ft-lbs of torque. Much more than that and you'll definitely
twist the transmission shaft. A "strengthened" version of this transmission
is in development by a list member. Further details forthcoming.
================
2.10) The Clutch
================
---------------------------------------------------
2.10.1) Who makes upgraded clutches for the J-body?
---------------------------------------------------
Carbon-Kevlar clutches are available from Mantapart.
Centerforce makes both OEM replacement clutches and a dual-friction clutch
for the J-body. Their current catalog only lists up to the 2.3L engine
available back in 1995, so check with them before ordering.
============
2.11) Brakes
============
-----------------------------------------------------
2.11.1) Are upgraded brakes available for the J-body?
-----------------------------------------------------
Yes. You should be able to find upgraded brakes for the J-body from most
major aftermarket brands like Raybestos, Performance Friction, etc.
----------------------------------------------------------------
2.11.2) Is there any way to convert my rear drums to rear discs?
----------------------------------------------------------------
Yes. A conversion kit is available from several sources, including
RK Sport. It's not a cheap conversion, but the braking power might be
well worth the cost. RK Sport's kit is $800.00.
---------------------------------------------------
2.11.3) What about cross-drilled or slotted rotors?
---------------------------------------------------
Cross-drilled and slotted rotors are both available for the J-body.
However, due to the nature of cross-drilled rotors liking to crack,
we recommend using slotted rotors.
PowerSlot slotted rotors are available from:
Landspeed Performance
888-69-SPEED, part no: 8234
Ask for Matt -- they don't have our cars in their catalog.
----------------------------------------------------------------------
2.11.4) How many times can I "turn" the rotors before I should replace
them?
----------------------------------------------------------------------
The J-body rotors, when stock, are very thin. They do not contain enough
metal to be "turned" more than once, but it is best to just replace them
instead of "turning" them. It may cost more, but new rotors will last
longer and be less susceptible to warping again.
------------------------------------------------------------------
2.11.5) What is the average number of miles a set of brakes on the
3rd Gen J-body last?
------------------------------------------------------------------
Anywhere from 20,000 to 30,000 miles. My first set, however, only lasted
12,000 miles. My second set have lasted at least 25,000. I should
probably get them replaced soon. =)
--------------------------------------------------------------
2.11.6) When I upgrade my pads, should I use carbon-metallics?
--------------------------------------------------------------
Carbon metallic pads have both their ups and downs. They do not perform
well while cold, but once they've warmed up, they perform much better than
stock. Members on the list have had good luck with Performance Friction
Carbon-Metallic pads, part number 5064 for the 3rd Gen J-body.
---------------------------------------------------------------------
2.11.7) What is that high-pitched "squealing" noise my brakes make...
---------------------------------------------------------------------
----------------
a) When braking?
----------------
This is probably due to accumulated brake dust. It means you need to
wash your car more often. =) But seriously, once the brakes have cooled,
either hose them out or get a professional brake cleaner and spray them
down. This happens more frequently on the front discs than the rear
drums.
-----------------------------------------------------------------
b) Only when I turn the wheel one way or the other while driving?
-----------------------------------------------------------------
It's time to see the mechanic. The side the brake is squealing on
could need replacement or there may be a more serious problem at hand.
Have your local dealer check it out, to make sure that braking force is
being evenly distributed between the brakes, and that there isn't
anything else inbetween the pad or rotor.
----------------------------
c) Until I apply the brakes?
----------------------------
The sensors on your brakes are notifying you that it's time to have the
pads replaced. The noise does not mean your brakes are going to fail,
just that the pads are getting thin (only 1/8" of material left) and
need replacement soon.
=======================================================================
3) Decoding your J-body's VIN Number
=======================================================================
I'll bet you didn't know that your VIN number actually has meaning! It's
actually very easy to decode. Here is a key for decoding your VIN number.
First digit is the place of origin. 1 is US and 2 is Canada and J is
Japan, etc.
Second is the company that made it. G is GM, but other companies like
Chrysler, for example have several that they use. Isuzu is 8.
Third (in GM) is the Division. 1 is Chevy, 2 is Pontiac, 3 is
Oldsmobile, 4 is Buick, 6 is Cadillac, and 8 is Saturn.
Fourth is currently the platform letter. J-bodies are (obviously) J.
In the '80s, however, it denoted the type of restraint system the car had.
Now, with just the first four digits and a little knowledge of GM
platforms, you can instantly narrow a car's identification down to within
a couple of possibilities.
Try a few (answers at bottom):
a. 1G1J b. 2G2W c. 1G1Y d. 1G4B e. 1G3A f. 1G6V g. 1G8Z h. 1G1G
i. 4G2J j. J81R
Fifth is the model name and sometimes trim line. All of the following 5th
digit codes go thru 1987, and I'm working on finding the ones for
Sunbird/fire and Cavalier up to today. I believe Cavalier just all
became "C" and I'm not sure about Sunbird.
Buick S SkyHawk
T SkyHawk Limited
E SkyHawk T-Type
Cadillac G Cimarron
Chevrolet
1982-83 D Cavalier
E Cavalier Hatchback
1984- C Cavalier
D Cavalier CS
E Cavalier Type-10, Cavalier RS
F Cavalier Z24
Olds C Firenza
D Firenza SX/LX
Pontiac B J2000, 2000, 2000 Sunbird, Sunbird
E J2000 S ('82 only)
C J2000 LE, 2000 LE, 2000 Sunbird LE, Sunbird LE
D J2000 SE, 2000 SE, 2000 Sunbird SE, Sunbird SE
Sixth and Seventh were the body style in the '80s. In the '90s, Sixth
has been body style and Seventh the restraint system. 1 is 2-dr. Coupe,
5 is 4-dr. Sedan, 8 is 5-dr. Wagon, 9 is an incomplete 5-dr. Wagon. A
seventh digit of 1 stood for manual belts and 4 for automatic belts. 0
meant incomplete vehicle (meaning the car was delivered from the factory
unfinished -- these vehicles are frequently converted for racing, agriculture, towing, etc.).
Eighth is engine. 1 was the 2.0 4-cyl. 4 is the 2.2 4-cyl. D was the
2.3 Quad 4. T is the current 2.4 Twin Cam Quad 4, which I have heard
referred to as "Iron Duke II". There have been countless others in this
place over the years.
Ninth is just a check digit.
Tenth is the year code. A=1980, B=1981, C=1982, D=1983, E=1984, F=1985,
G=1986, H=1987, J=1988, K=1989, L=1990, M=1991, N=1992, P=1993, R=1994,
S=1995, T=1996, V=1997, W=1998, X=1999, and Z=2000.
Eleventh is the plant code. J is Janesville, 7 is Lordstown, and either
B or M is Lansing, but I forget which applies to the J-body.
The last six digits are the unique serial number of the car.
It's interesting to note that the letters I, O, and Q will never appear
in a VIN. If they are, it's really a T, an I, or a zero and there's
either something on the plate or it has been damaged.
Examples*:
1G2JB1417L7304855 would be a 1991 Pontiac Sunbird Coupe made in
Lordstown with the 2.0 4-cyl and automatic seatbelts.
1G1JC5442P7258311 would be a 1993 Chevrolet Cavalier Sedan made in
Lordstown with the 2.2 4-cyl and automatic seatbelts.
A new system will be adopted for 2001. I think it will be a 20-digit
VIN, but I haven't heard yet from a definite source.
Answers to first-four-digit questions:
a. Chevrolet Cavalier (If you got this one wrong, you
don't pay enough attention to your own car!)
b. Pontiac Grand Prix (1988-Current)
c. Chevrolet Corvette (If you said Malibu, drop and do
twenty!)
d. Buick Roadmaster (Any 1980-87 Buick with air-bags
would also be acceptible.)
e. Cutlass Ciera would be my first guess, but almost
any 1980-87 Oldsmobile would also have this number.
f. Cadillac Catera (or Allanté)
g. Any Saturn (so far)
h. Chevrolet Monte Carlo (1988) (If you said 2001 Bel
Air, you should be working for GM, seriously.)
i. Pontiac Sunfire (Did the 4 throw you?)
j. Chevrolet/Geo Spectrum or Storm (They were made in
Japan by Isuzu, but 1R is still a Chevrolet R-body.)
==========================================================================
LEGAL NOTICE: The author and contributors to this FAQ do not endorse
speeding, unlawful modifications, or skirting the law. We are not liable
for any information divulged in this FAQ, accurate or inaccurate. It is
here solely for INFORMATIONAL PURPOSES, and does not make any claims to
a specific purpose other than disseminating information.
==========================================================================
Source: The J-Body Organization