Created & Maintained by J. Casalino ([email protected]). Converted to HTML by "[email protected]. Special thanks to the following contributors: Herman Sun, Dustin Simmons, Matt, Ray Johnson, Rogue Leader (Tom Lomino), Tom (FireStryker), Chris McGrady, Oscar Gonzalez, Karl Kopp Modification History: v0.0 05/28/98 Created FAQ & posted to the list. v0.1 06/02/98 Updates and corrections. Merged sections 1 and 2. Added sections 3 and 4. Added several questions to the existing sections. v0.2 06/20/98 Re-numbered a couple of sections. Added a lot more questions to the existing sections. Expanded the history section. v0.3 07/xx/98 Filling in answers to more questions. ALMOST DONE! New sections finished: 2.6. Minor wordsmithing to existing sections. Looking for answers to several questions below. Look for the arrow *****>. If you have info, please e-mail me. See an inaccuracy? Want to add a question to the list? Have the answer to an unanswered question? E-mail me with your suggestions and comments! ========================================================================== About the Author ~~~~~~~~~~~~~~~~ I currently own a 1995 Pontiac Sunfire SE Coupe, with the 2.2L OHV engine, and the 5-speed transmission. Previous to the Sunfire, I owned a 1987 Chevrolet Cavalier Z24, with the 2.8L V-6 MPFI engine. I have been a contributing member to the J-body list for over a year now. Purpose ~~~~~~~ This FAQ was created to help alleviate some of the common questions that have plagued the J-body mailing list in the past. I am not a mechanic, but several people on the mailing list are, so the information you find here has been verified for accuracy by the subscribers to the mailing list. Common terms used ~~~~~~~~~~~~~~~~~ You will notice many abbreviations and perhaps some unfamiliar technical terms used in this FAQ. You will find definitions for almost all of these terms here. If you can't find what you're looking for here, you might consider reading up a bit more on the basic components used in a car. As always, don't be afraid to ask. Even your local shadetree mechanic may be able to explain the term to you. OHV Overhead valve (engine) SOHC Single overhead cam (engine) DOHC Dual overhead cam (engine) Dyno Short for "dynamometer" -- the machine that most accurately tests horsepower and torque at the wheels. TSB Technical Service Bulletin - issued by GM to address a certain problem or symptom and how to fix it. Usually fixes are done under warranty. TSB's are not as bad as recalls. Mailing list info ~~~~~~~~~~~~~~~~~ Two mailing lists currently exist. There is the more heavily moderated list ([email protected]) and the less-heavily moderated list ([email protected]). In the interest of information, I subscribe to both, because the members are not all the same. For subscription information to the less-heavily moderated list, visit http://www.z24.com. ========================================================================== ========================================================================== 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? 1.10) 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? 2.3) *reserved for future use* 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 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? 2.7) 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 4) Homepages 4.1) Mailing list members' homepages 4.2) J-body related homepages ========================================================================== ========================================================================== ========================================================================== 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. --------------------------------------- 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.org or http://www.alldata.com. ========================================================================== 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 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 # [email protected] RKSport Website: http://www.rksport.com E-Mail: [email protected] [email protected] 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 ------------------------------------ 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 |xxx @ 5250 |xxx @ xxxx | Torque @ rpm |xxx @ xxxx |xxx @ xxxx |xxx @ 4000 |xxx @ xxxx | 0-60 mph | | | | | 1/4 mile | | | | | --------------------+-----------+-----------+-----------+-----------+ |2.8 V6 |3.1 V6 | --------------------+-----------+-----------| HP @ rpm |120 @ xxxx |130 @ xxxx | Torque @ rpm |185 @ 4000 |195 @ xxxx | 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 causing 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? ----------------------------- Two words: BAD IDEA. The J-body does not take well to a NOS system. The extra strain that the NOS can put on the engine will certainly cause parts to "expire" prematurely. One particular member of the mailing list tried NOS on his 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. ======================= 2.5) 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. 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 ----------------- *****> Anyone have any good info to put here? =================== 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 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. The part number for a '98 J-body is 22604347. It is listed in the computer simply as "Brace". For the '96-97, try 22642387. Aftermarket bars also exist. One is made by Freedom Design. It is polished forged aluminum, and it costs about $100. Part #63102. Mantaparts 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. -------------------------------------------------------------- 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. ===================== 2.7) 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) *****> What about first and 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, 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. --------------------------------------------------------------- 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. ======================================================================= 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. *****> What is an "incomplete" vehicle? 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 Allanti) 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.) ========================================================================== 4. Homepages & Links ========================================================================== American 4/6 Cyl Performance http://www.geocities.com/motorcity/4601 Backyard Motorsports http://www.pressenter.com/~blrauchw Quad4 Performance Trends http://home.earthlink.net/~quadpower ========================================================================== 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. ==========================================================================