As the FAQ grows, its getting sort of difficult to use. This post will list the topics, by thread, in the order they appear in the thread:

PAGE 1:

Wheel stripping, polishing & painting

Wheel & Tire Basics

Wheel & Tire Weights (4th Gen)

Acceptable Wheel & Tire Combinations (4th Gen)

What size tires fit what size wheels?

17x9.5 & 17x11's (4th Gen)

Why won't my new wheels fit over the rear hubs? (early 4th Gen)

Weld Pro-Stars & Draglites (LT1 4th Gen) - MOVED TO DRAG WHEEL FAQ

Bogart Drag Wheels (4th Gen) - MOVED TO DRAG WHEEL FAQ

Finding more info about tire choices

C6 OEM wheels on a 4th Gen - Moved to its own thread

Can I widen my wheels?

What offset do I need (4th Gen)

PAGE 2:

18x10.5 wheel/tire fitment w/ photos (4th Gen)

Weld Aluma-Star 2.0 (4th Gen) - MOVED TO DRAG WHEEL FAQ

 

Hopefully this will give you all the information you ever wanted to know about polishing and painting your wheels. If we can keep this thread going – then maybe this section won’t become 10 questions a day about wheel polishing and painting – like the appearance section became 10 questions a day about headlights (for a while).

Stripping
I don’t know if there are any guides out there on this – but I am sure there are. Either way – it isn’t rocket science – so anyone can do it. I will go ahead and write a “guide” here as to how me and a buddy stripped his ’02 WS6 wheels. But – use it at your own risk – I am not responsible for anything that goes wrong with your project. I also do not know how this applies to powdercoated wheels. If you are trying to strip them though – I don’t see how this could hurt.

Materials needed for stripping:
•Klean-Strip Aircraft Remover. This is available at Wal-Mart in the automotive section. You can always play it safe and just get 1 can for each wheel – although you will probably only use 2-3 cans, which is what I would recommend. Whatever you don’t use, you can take back.
•Soft plastic scraper. (Bondo Spreaders, etc.)
•Latex Gloves (you don’t have to use them, but I would like to watch you use this stuff without them – it WILL burn you – even if you are used to paint chemicals, etc.)
•Masking Tape (Optional – if you have any areas you do not wish to be stripped or possibly bubble up).
•Rags, towels, waterhose…(Terry cloth towels recommended).
(And please – do all of this outside – this stuff is harmful to your health if ingested).

1. Wash the wheels off first. Don’t have to go to town – just get all the top junk off that you can. This will allow the stripper to get directly to the clear coat or paint that you are trying to remove.
2. Tape off wheel if necessary. Tape off any painted or clear coated areas you do not want to be stripped. I would at least double up on the tape – as the stripper is powerful enough to eat through it. The stripper will not damage tires to my knowledge, so there is no need to tape them up.
3. With gloves on, start spraying the stripper. Follow the directions on the can as always. We used several heavy coats of stripper – probably wasteful, but it worked.
4. Let the coated wheel sit outside, out of direct sunlight for 15-20 minutes/
5. Take scraper and scrape gunk off of wheel as much as possible.
6. Then re-wash the wheel with a waterhose and towel (I recommend terry cloth towels because they do not scratch easily) removing all the stripper and loose clear coat.
7. Repeat process until desired results are achieved.

Now you are ready to polish the wheels.
Most wheels that have had clear coat on them are not too bad underneath. In the case of my buddy’s wheels, they were highly polished underneath the clear coat, the clear coat was all that was dull.

If they are not as you want them – start off with the non-abrasive polishes first (again, read up on all the different materials used for polishing). You can probably get by with some Mother’s, applicator pads, and terry towels.

Polishing
There are a few very nice guides out there – read them, study them, use them!

First One: Mag and Aluminum Wheel Polishing at EastwoodCo.com

Second One: Getting Ready to Buff – Surface Conditioning and Smoothing at EastwoodCo.com

Third One: Polishing “How To” at Todd2001SS’s website

Everything you need to do this can be had from www.eastwoodco.com.
Below are some direct links to sections you may want to check out.

Main Metal Buffing and Finishing Page
Buffing Category
Compounds Category
Buffing Kits Category

Familiarize yourself with all the polishing products available and their uses.

Other notes:
•Not all polishing jobs require such hard work and so many tools. If you are just trying to get your already polished aluminum wheels just to shine back up – you may want to try Mother’s Billet Polish, it is a very high quality polish that works well. This is different than Mother’s Aluminum Polish.
•Depending on the severity of the wheels’ dullness, you may need some buffing wheels or various bob’s (available at Eastwood) to get the shine you desire.
•High speed with a wheel or bob is not necessarily the best way. You can probably achieve the results you desire with a cordless drill.
•If your wheels are scratched – you are going to have to do more than just use some Mother’s polish and a rag – read the guides above for more info.
•In order to get a highly polished look out of a previously unpolished or not very highly polished wheel will take a lot of time. The Polishing “How To” at Todd2001SS’s website is very descriptive on the sanding process. This is how you will achieve the maximum shine. Sand with several grits working your way down.

Painting
This is how I painted my wheels. I can't guarantee you anything on this - or if it is the best solution, if it is easier/cheaper/better than powdercoating, etc.

Materials I used for painting:
•Dupli-Color High Performance Wheel Coating (Paint Color, and Clear)
•Mineral Spirits, Acetone, or your cleaner of choice.
•Anything to scuff the surface.

1. First thing you need to do (after stripping of course) is prep your wheels to accept the paint. The paint needs something to stick to. It isn't going to bond well with smooth metal. I found on my wheels (Polished Aluminum Eagle 077's) that a Scoth-Brite pad is too little of a scuff. You need something a little bit more than that. You do not want to cut any "grooves" into the wheel, but you want it to be very scuffed. Until someone tells me they have found the miracle product that perfectly scuffs all wheels (steel, aluminum, etc.) then I am just going to leave it at this: EXPERIMENT. Use some common sense, and when you find the "ideal scuff", then go with it. Some wheels are going to be softer metal than others, etc. So I can't tell you what will work with yours.

2. Clean the wheel, good! You don't want any oily surfaces anywhere that you are painting. Mineral Spirits or Acetone should be good.

3. Start your painting. First off, read these two pages:
Wheel Projects Page (from Dupli-Color).
Wheel Tips (from Dupli-Color).

My tips - Use several (and I mean several) thin coats. This stuff is thick, so "thin" coats is kind of a loose term. What that means is don't cake it on.

Definitely use the clear coat!!! I don't know why I even get questions like this: "Should I use the clear coat stuff too?" WHY WOULDN'T YOU?

Just use common sense. Even if you have no extensive knowledge of painting, etc., you can do this. I am not a paint & body man by NO means whatsoever. It's pretty strait forward - but I see lots of questions.

"Does this Dupli-Color stuff hold up?"
It seems to be holding up just fine for me. You will have to use a tire shop that knows what they are doing though in order to keep the rim from being eat all to heck. One of my tires has been put on 2 times, and it is still looking good. This has a lot to do with the hardness factor of the paint and the experience/equipment of the tire shop.

So the quality and longevity of this process is sort of up to you. Make sure you give the paint a good mating surface, and follow the directions on the can. It gives you specified times and everything else to follow. FOLLOW THEM! I waited too long to clear coat one of my wheels and it dry cracked the paint surface horribly. After you get finished painting, let the wheel fully cure.

And don't do this in cold weather - it will not go well. You need the right temperature and low humidity to get it perfect. If it is raining - don't try. If it is -20°, don't try. Use some sense.

_________________________________________________
That’s all folks. If anyone has anything to add, please post up.

 

Of my wheels?
http://blackbowtie.web1000.com/images/077Tease/
http://blackbowtie.web1000.com/images/94BlackBowtie/
A) I definitely wouldn't sand the clear coat.
B) I probably wouldn't paint over the clear coat.

The clear coat on the salad shooters isn't great. It was wearing off on my set long ago, and I know it has done it too others as well.

Sanding the clear coat you are just going to thin it down, and possibly just get to the bare metal. Then you are going to have a slick, metal surface with no prep basically to stick to, which will also be on a different level than the clear coat (maybe not visually right off, but physically it will be).

I have heard of painters painting over clear coat before, so that isn't a long shot, but you definitely wouldn't want to do it without sanding first though.

You're best bet is going to be go ahead and strip the wheels, then sand them. I would suggest working from a very fine grit sandpaper toward the heavier grits until you reach the right spot. You don't want grooves in your wheel, just a nice mating surface for the paint.



I did use the stripper on one of the center caps, and it messed it up somewhat - so I just sanded them down really good until the label was smoothed off, and then painted over them.

I haven't stripped any chrome off - and I'm not really sure how too - but I am guessing it takes some acid and a professional.

 

Hey Guys!

At the request of some members (and the admin! ) we'll try a simple FAQ.

We'll add to this thread answers to the more common questions we have seen relating to wheels and tires.

If any member has additional information they feel would be of value to this thread, please email one of the below members and we will look at adding this information to the thread.

JasonD jason@camaroz28.com
Injuneer injuneerzz@aol.com
Brent94Z bfranker@tampabay.rr.com

If you prefer to post rather than email it to one of us, please post the info in this thread and we will update the FAQ.

Thanks for you input!

(Note: this will be lacking for the first few days as we gather some info )

Also, while this may appear to be primarily a 4th gen FAQ, that is only because the information we have is primarily related to 4th gens. This FAQ is intended to be for all generations so if you have information for any generation, please let us know!

 

Wheel and Tire basics…

Q. What is the bolt pattern for my car?

A. 3rd and 4th Gen F-Bodies are 5 x 4.75" (120.65mm)

Q. Can I use 5 X 120mm bolt pattern wheels on my 3rd or 4th Gen?

A. Depends.

The 5 x 120mm bolt pattern is commonly used on BMW's. The wheels will bolt on your car, but they will not bolt on correctly. There has been significant debate here as to whether they increase the risk of broken studs or a wheel coming off. Some people have posted they run that bolt pattern "with no problems", others have cited instances of broken studs and loosened lugs. I (Injuneer) personally do not recommend it. Some disagree with me. In the event of a serious accident, the fact you were using the incorrect wheels on the car might expose you to increased liability, whether the wheels caused the accident or not. I recognize this is a very conservative viewpoint - I just want you to be aware of the fact it is not a simple "yes" or "no" issue. CamaroZ28.com can not recommend or assume liablilty for use of the incorrect bolt pattern.


Q. What do the numbers 245/50-16 mean on the side of my tire?

A. The first number (245) is the width of the tire in millimeters. The second number (50) is the aspect ratio of the sidewall as compared to the width of the tire. What this is saying is the sidewall is 50% of the width of the tire. In this case, 122.5 mm is the height of the sidewall (distance from the wheel to the top or bottom of the tire). The third number (16) is the wheel diameter in inches. This tire is made to fit on a wheel with a 16 inch diameter. It is one of the great wonders of the world as to why they mix Metric (millimeter) and British (inches) units but they do

The above information is useful when trying to calculate the overall diameter of your tire… how tall it is. You will often need this to determine if you can change sizes without affecting your speedometer or what you need to put in your Hypertech Power Programmer for tire height. On 4th gens, the base cars came with 245/50/16 sized tires. Cars like the SS or WS6 came with 275/40/17 sized tires. These two tires have the same basic overall diameter which makes it convenient for GM because no speedo recalibration or gear changes were needed. We can put what was learned above and prove this too! However, you need to know that there are 25.4 mm per inch. With that info you can figure the overall diameter of your tires.

245/50/16. The wheel diameter is 16 in x 25.4 mm/in = 406.4mm. The sidewall is 245mm x 50% = 122.5 mm x 2 (because there are two sidewalls!) = 245mm. This gives you a total tire diameter of 651.4mm or 25.65" (651.4 / 25.4).

275/40/17. The wheel diameter is 17 in x 25.4 mm/in = 431.8mm. The sidewall is 275mm x 40% = 110mm x 2 (because there are two sidewalls!) = 220mm. This gives you a total tire diameter of 651.8mm or 25.66" (651.8 / 25.4).

And, you'll notice that the most popular size for the guys who run 11" wide rear wheels is 315/35/17 and this is because, again, this tire maintains the same basic overall diameter which keeps the look of the stance "correct" and makes it so speedometer changes will not be needed.

315/35/17. The wheel diameter is 17 in x 25.4 mm/in = 431.8mm. The sidewall is 315mm x 35% = 110.25mm x 2 (because there are two sidewalls!) = 220.5mm. This gives you a total tire diameter of 652.3mm or 25.68" (652.3 / 25.4).

Common Wheel Terminology

I found a page with a Google search, Yokohama - Understanding Your Tires, which has a lot of good information and have copied and pasted some of it below...

Wheel Backspace
This is the distance from the back edge of the wheel to the hub mounting surface. To determine the wheel backspace:

1. Position the wheel face down.
2. Lay a straight-edge across the back of the wheel. Measure the distance from the straight-edge to the wheel's hub mounting surface.

Wheel Offset
Diagram courtesy of Tire Rack:



The wheel's offset is the distance from its hub mounting surface to the centerline of the wheel. The offset of a wheel can be one of three settings:

• Zero offset: The hub mounting surface is even with the centerline of the wheel.
• Positive offset: The hub mounting surface is toward the front or wheel side of the wheel. Positive offset wheels are generally found on front-wheel drive cars.
• Negative offset: The hub mounting surface is toward the back or brake side of the wheel's centerline. "Deep dish" wheels are typically negative offset. Offset can be calculated by positioning the wheel on a flat surface and measuring its overall width and backspace as shown below. Divide the overall width by two, then subtract this result from the backspace value.

For a good pictorial of offset and backspace as well as calculating your lug pattern, the Yokohama - Understanding Your Tires page has a good write-up.

[CAUTION] As informative as the Yokohama page is, it is a bit misleading. In the diagrams that deal with backspace and offset, they use the term "rim width" and showing that dimension extending across the full width of the rim, including the bead retention flanges, or "lips". This is NOT the basis of the dimension that will be quoted in the wheel's "size". The true rated width of a wheel is measured INSIDE the bead retention flanges, and represents the width of the tire bead when the tire is mounted on the wheel.

For example, the stock 4th Gen V8 wheel is 16" x 8". If you were to physically measure the total diameter and width of the wheel, including the bead retention flanges, it would measure closer to 17" x 9". That is because the bead retention flanges (or "lip" to most of us) adds about 1/2" to the overall width of the wheel, on each side, or 1" total. Similarly, the outside diameter of the "lip" will typically be 1" larger that the diameter at the bead seat. [note added by Injuneer]

Other pages with good tire information and diagrams...

Wheel Basics from the Edmunds site.
Wheel Technical Information

And, of course, our very own Supporting Vendor, Discount Tire Direct has an EXCELLENT page with tire information.

From the Discount Tire Direct - Info Center web page.

Tire Safety, Selecting the Right Tire, Tire Construction, Reading the Sidewall of a Tire, Tire Dimensions, Tire Dimensions Made Simple, Treadwear, Traction, and Temperature, Speed Rating, Load Index, Tire Terminology, Wheel Offsets, Wheel FAQ, Wheel Torque Chart, Improving Wear - Air Pressure, Improving Wear - Alignment, Improving Wear - Balancing, Improving Wear - Tire Repair, Improving Wear - Tire Rotation

Please try to support our camaroz28.com Wheel and Tire guy, Chris at Discount Tire Direct! Chris@tires.com

 

4th Generation Wheel and Tire Weights

Note: Many of these were taken with a bathroom type scale and may not be 100% accurate. If you have additional weights or weights you believe are better, please email to one of us listed in the first post and we'll update the thread.

• 58 lbs - AFS chrome 17x11 GS offset wheel with new Dunlop SP8000 315/35/17 tire
• 56 lbs - AFS chrome 17x11 GS offset wheel with BALD Dunlop SP8000 315/35/17 tire :-)
• 56 lbs - 18x9 chrome Cobra R replica wheels with 285/35/18 tires
• 55 lbs - AFS silver 17x11 GS offset ZR1 wheel with new tire
• 55 lbs - 17" Prime chrome 5 Stars with 275/40 tire
• 55 lbs - 17" chrome Firewhawk wheel with new tire
• 54.5 lbs - Replica SS wheel with Khumo 712 275/40 tire
• 52 lbs - AFS chrome 17x9.5 ZR1 wheel with new Dunlop SP8000 275/40/17 tire
• 50 lbs - OZ Monte Carlo 17x9.5 with 1/3 tread 275 GSC
• 50 lbs - AFS polished 17x11 GS offset ZR1 wheel with new 315 BFG Comp TA drag radial
• 48 lbs - 16x8 stock chrome 5 star with Kuhma Estca Supra 712 tires (V rated)
• 47.36 lbs - 17" 10-spoke Camaro SS wheel (chrome) with BFG G-Force T/A KD tire/air
• 45 lbs - 99 TA stock 16" chrome wheels and tire (SZ 50)
• 44 lbs - 93-96 Camaro wheel with Nitto drag
• 41.5 lbs - 93-96 Camaro wheel with bald 255 BFG drag radial
• 40 lbs - Weld Pro Star (15x10) with new Hoosier QTP 28x11.5-15 (no tube)
• 40 lbs - Centerline Telstars 15x10, 26/11.5/15 MT ET streets with tubes
• 35.3 lbs - New Dunlop SP8000 315/35/17 tire
• 31 lbs - New Dunlop SP8000 315/35/17 tire - hmm?
• 31 lbs - Kumho Victoracers 275/40/17 tire
• 30 lbs - New Dunlop SP8000 275/40/17 tire
• 29 lbs - 97 to 99 Vette standard rear wheel
• 28 lbs - Kumho Victoracers 315/35/17 tire
• 27 lbs - Weld Pro Stars (15x3.5) with Cooper 165R tire
• 27 lbs - 18x9 chrome Cobra R replica wheel
• 26 lbs - Centerline Telstars 15x4, 26/7.5/15 (4.8 tread width) M/T sportsman
• 25.5 lbs - Hoosier A3S03 Autocross tire 315/35-17
• 25 lbs - Firestone SZ50EP stock size tire
• 25 lbs - New Futura 275/40/17 tire
• 24.5 lbs - Goodyear GSC 245/50/16 tire
• 24 lbs - 97 to 99 Vette magnesium rear wheel
• 22.5 lbs - Hoosier A3S03 Autocross tire 275/40-17
• 22 lbs - 90 Vette stock wheel 17x9.5
• 22 lbs - Hoosier R3S03 275/45/16 tire
• 22 lbs - 01 Camaro SS 17x9 wheel
• 22 lbs - 2 piece Centerline Sabre type 17x9.5 wheel
• 21.64 lbs - 17" 10-spoke Camaro SS wheel (chrome)
• 21.5 lbs - 97 to 99 Vette 18x9.5 wheel
• 20.06 lbs - 00 Vette standard rear wheel
• 20.06 lbs - 17" 5-spoke (ZR1 style) Camaro SS wheel (painted)
• 20.5 lbs - OE ZR1 17x9.5 wheel
• 20.5 lbs - AFS replica 16" SS wheel
• 20.1lbs - 97 to 99 Vette magnesium front wheel
• 20 lbs - CCW 17x10 wheel
• 20 lbs - CCW 17x11 wheel
• 20 lbs - 3 piece Centerline Sabre 17x9.5 wheel
• 19.5 lbs - 1996 stock Camaro wheel
• 19.5 lbs - Stock 5 star 16" Z28 wheel
• 19.44 lbs - 16" Camaro Split 5-spoke ("Snowflake" style) wheel (chrome)
• 19 lbs - 2000 stock Camaro wheel
• 19 lbs - 97 to 99 Vette 17x8.5 wheel
• 18-19 lbs - Centerline 17x9.5 wheel
• 18.08 lbs - 00 Vette standard front wheel
• 18 lbs - Fiske FM5 17x9.5 wheel
• 17 lbs - 2000+ stock Camaro wheel (different than above?)
• 13 lbs - Weld Pro Star (15x8)
• 10 lbs - Weld Pro Star (15x3.5)
• 10 lbs - Bogart DragStar 15x10 racing wheel
  

3rd Generation Wheel and Tire Weights

2nd Generation Wheel and Tire Weights

1st Generation Wheel and Tire Weights

 

Acceptable 4th Gen Wheel and Tire Combinations

Questions often get asked if a certain sized wheel and tire will fit on a 4th Gen Camaro or Firebird/Trans Am. This especially comes up with 18, 19, and 20 inch wheels as they are not as common and tire widths and aspect ratios seem to vary more.

I have created a page which shows pictures of several different combinations so you can see what it might look like. We will also try to update this reply with all known variations. If you have a 4th Gen which has a wheel/tire combo not listed here, please email one of the above people mentioned in the first post. If you have a picture of your car and would like it placed on the below page, then you can email me at bfranker@tampabay.rr.com and I'll see about sticking it up!

Tire Sizes For 4th Generation F-Body Wheels - Pictures included

15"


16"


17"


18"
275/35/18 on 18x? wheels
275/35/18 on 18x9.5 wheels
265/35/18 on 18x8 wheels
285/35/18 on 18x9.5 wheels
275/40/18 on 18x9.5 wheels
265/35/18 on 18x9.5 wheels

19"
275/30/19 on 19x9.5 wheels

20"
285/30/20 on 20x10 wheels

Acceptable 3rd Gen Wheel and Tire Combinations

Acceptable 2nd Gen Wheel and Tire Combinations

Acceptable 1st Gen Wheel and Tire Combinations

 

NOTE: We might need to combine this one with the post above

What size tires fit on what size wheels?

The following table is based on manufacturers’ recommended wheel width data. They are “guidelines”, since each manufacturer sets his own limits of what size wheel the tire requires. When you have selected a specific brand of tire, and a size, check that manufacturer’s recommendation for wheel width. This data is available on tire shop websites, or on the manufacturer’s website (e.g. – Nitto, BFG, etc.)

TIRE SIZE: TIRE DIAMETER; WHEEL WIDTH

245/50-16: 25.7” diameter; 7.0” – 8.5” wide wheel
255/50-16: 26.0” diameter; 7.0” - 9.0” wide wheel

245/45-17: 25.7” diameter; 7.5” – 9.0” wide wheel
275/40-17: 25.7” diameter; 9.0” – 11.0” wide wheel
285/40-17: 26.1” diameter; 9.5” – 11.0” wide wheel
315/35-17: 25.7” diameter; 10.5” – 13.0” wide wheel (max wheel width on a 4th Gen without mini-tubs is 11.0")

245/40-18: 25.7” diameter; 8.0” – 9.5” wide wheel
255/40-18: 26.0” diameter; 8.5” – 10.0” wide wheel
265/35-18: 25.3” diameter; 9.0” – 10.5” wide wheel
275/35-18: 25.5” diameter; 9.0” – 11.0” wide wheel
285/35-18: 25.9” diameter; 9.5” – 11.0” wide wheel
295/35-18: 26.2” diameter; 10.0” – 10.5” wide wheel
315/30-18: 25.5” diameter; 10.5” – 11.5” wide wheel
335/30-18: 26.1” diameter; 12.0” – 13.0” wide wheel

245/35-19: 25.8” diameter; 8.0” – 9.5” wide wheel
255/35-19: 26.0” diameter; 8.5” – 10.0” wide wheel
275/30-19: 25.5” diameter; 9.0” – 10.0” wide wheel.

The data is copied from various manufacturers’ tables. These are the recommended wheel widths. Many people will note, for example, that they have put a 315/35-17 on a 9.5” wide wheel, and it “works fine”. Just keep in mind:

-scrunching the tire on too narrow a wheel will alter the contact patch.

-scrunching the tire on too narrow a wheel will increase tread flex, increasing carcass temperatures and shortening tire life.

-if you have a serious accident, with the wrong match on tires and wheels, a good forensic engineer will be able to put the suspicion of blame on you in court, whether the accident was your fault or not.

 

17x9.5" and 17x11" Wheels on a 4th Gen

A popular setup seems to be:

- Front: 17x9.5" wheels with 275/40-17 tires
- Rear: 17x11" wheels with 315/35-17 tire

To make this work, you need wheels with the correct offset. Offset is a measure of how far the centerline of the wheel is pushed in over the mounting hub. For example, a 50mm offset pushes the centerline of the wheel about 2" deeper in to the wheel well, than if it had "0" offset.

For the 4th Gens, recommended offsets are:

Front: 17x9.5" use an offset in the range of 45mm - 56mm. Here are some examples of front wheels:

= = = = = = = = = = = = = = = = = = =

56mm offset in front:



(17x9.5 56mm front only - rears are 17x11 50mm w/ 315/35)

= = = = = = = = = = = = = = = = = = =

49mm offset


(17x9.5 front and rear)

= = = = = = = = = = = = = = = = = = =

45mm offset:

http://www.kellydrown.com/Personal-F...ites/i-bZdLcSx

(17x9.5 front only - rears are 17x11 45mm w/ 315/35)

= = = = = = = = = = = = = = = = = = =

38mm offset:
[link no longer works]

= = = = = = = = = = = = = = = = = = =

If you run greater than 56mm offset, you run the risk of the inner edge of the wheel contacting the steering knuckle. If you use anything smaller than 45mm offset, the tire is going to stick out from under the front fender.

17x11" use an offset of 50mm. (50mm offset yields a backspace of 7.93 to 7.97” depending on manufacturer). If you go any larger on the offset, the inner edge of the tire will be hard into the inner fender liner. Any less offset, and the tires will start to stick outside the fender line, when you look straight down from above. 45mm is about as low as you can go and keep them under the fenders.

At least one popular wheel retailer, AFS, indicates that a 38.5mm offset is better for Trans Ams, while all other 4th Gens need the 50mm offset. I have never found any evidence to support the use of 38.5mm offset wheels on the back of a 4th Gen, and all the pictures I have ever seen show the tires outside the fenders.

AFS also indicates the 17" wheels can not be used on 4th Gen convertibles. This is not correct. While GM never put the 17" WS6 or SS wheels on the early convertibles, many people have put them on, with no problems at all. I was personally involved with putting the 17" ZR1/Grand Sport offset wheels on a 97 30th SS convertible, and it had the exact same wheel wells as my 94 Formula coupe.

50mm offset: (see also 56mm, above):


= = = = = = = = = = = = = = = = = = =

For the 17x11 wheels, you MAY need to do one or more of the following:

1. Cut the outer, projecting edge off the jounce bumper bracket. With the car at normal ride height, the edge of the bracket will be slightly inside the opening in the rear of the wheel. When you try and jack the car by the body, as the wheel drops relative to the chassis, the bracket will catch on the inside edge of the rim and gouge it.



Some people do not cut the brackets - that seems risky to me. Others completely remove the jounce bumpers. That is risky as well. The jounce bumpers keep the chassis from slamming down on the rear axle assembly. They also protect the shock absorbers from excessive compression, which can damage them.

2. Hammer the inner fender liners. The tire may hit at the front of the wheel well. You take a 3# hammer and bash in the area where it rubs. Make sure your back seat is in the upright and locked position. If not, hammering on the wheel well could move the pin for the seat back and make it diffcult to latch the seat.



3. Recenter the body over the rear axle with an adjustable panhard rod. If the clearance between the tire and the inside edges of the tire and the inner fender liner are not equal on both sides of the car, you may need to adjust the side-to-side centering.

4. Roll the fender lip. At the edge of the wheel opening, there is a 3/4" wide horizontal "lip" that sticks straight out toward the edge of the tire. If you use an offset less than 45mm, if your body is not correctly centered over the axle, or maybe if you have soft panhard rod bushings, its possible for the lip to hit the sidewall of the tire on hard cornering, or even on a really heavy shift. To prevent this, the lip may need to be "rolled" up so it doesn't point at the tire.

Several ways to do this, including rolling a baseball bat between the tire and the fender, lightly hammering the lip, using a tool like "The Jimmy" that grabs the lip and bends it upward at a 45-degree angle, or using a fender lip rolling tool like the one that The Eastwood Company sells (about $300). It is likely that the paint on the lip will chip as the lip bends. To prevent the chips from extending to the outer surface of the fender, you take a razor blade, and cut into the paint on the flat part of the lip, so when the paint cracks, it cracks in a straight line. Its best to use a little touch-up paint to seal the cracks when you are done. It will not be visible. I've also heard that if you use a heat gun on the paint as you are trying to bend the lip upwards, it will reduce/eliminate cracking of the paint.

NOT ALL 4th GENS ARE THE SAME, and not all tires are the same. Several people have managed to put the 17x11's on the back with no problems at all. Others have had to do everything that I mentioned above. There is no "correct" answer - each car is different.

(In process...... more to be added, including photo links)

 

WHY WON'T MY NEW WHEELS FIT OVER THE REAR HUBS ON MY 4TH GEN?

The 1993 to "late" 1996 4th Gen F-Bodies have a larger hub on the rear axle than on the front spindles. The rear axle hubs are about 0.03" larger in diameter than the front hubs. This problem was corrected in late 1996 model year or possibly in early 1997.

As a result, if you buy C4 or C5 wheels, or if you buy 1997 or newer F-Body wheels, they may not fit on the rear hubs of your 1993-1996 F-Body.

The solution is very simple. First, DO NOT FORCE THEM ON WITH THE LUGS! Very dangerous, and you may not be able to get them off. You need to lightly sand or grind (e.g. - Dremel) the inside diameter of the hub hole in the back of the wheel. Don't go nuts.... just remove enough metal so the wheel cleanly fits over the rear hubs, with no interference.

Think about doing this to all 4 wheels, so you can "rotate" the tires in the future.

This will not harm the wheels.... you are taking off the thickness of a sheet of paper. Just be sure you do a neat, smooth job. This will also NOT affect the centering of the wheels on the hubs. The 4th Gen wheels are "lug-centric" - they are centered by the conical lugs, not by the hubs.

 

Got a good writeup for us?

Send it via PM to Injuneer or Brent94Z. You will be given full credit for whatever you contribute.

 

HOW CAN I FIND MORE INFORMATION ABOUT TIRE CHOICES FOR MY CAR?

Go to Tire Rack.

http://www.tirerack.com/

Click on "tires by size" (lower left corner)

Enter the size tire you need.

You will get a list of many different tires that Tire Rack carries in that size. Tire Rack does not have Nitto, which is a popular brand. The price of each tire is indicated. They will range from "all season" to "ultra high performance summer".

For a tire that interests you, click on "survey results". That will give you a numerical rating, based on user feedback, for things like dry traction, wet traction, treadwear, noise, comfort, etc. While you are in this screen, you can click on "Compare this tire to other......" and you will get a list of all the tires in that category, rated from top to bottom overall.

Not an "absolute" evaluation of the tires, but they also include test results and reviews for many tires.

NOTE: This is not an endorsement of Tire Rack or their products. Tire Rack is not a supporting advertiser on this forum. Feel free to use their database, then start shopping around. Some local dealers will "match" the Tire Rack price if you show them the numbers.

 

C6 OEM WHEELS ON A 4th GEN

Moved to its own thread. See "stickies" at top of forum listing.

 

CAN I WIDEN MY WHEELS?

The best source for info on widening wheels..... the limits, related problems, and a source for the work..... is the writeup by Keith at ws6.com. He had a shop in Monrovia, CA widen his stock 17x9 WS6 wheels to 17x11". I've seen work from the shop in Monrovia, actually a 17x9" SS wheel that was narrowed to 6" wide, and the quality of work is exceptional.

http://www.ws6.com/wheels.htm

 

WHAT OFFSET DO I NEED FOR MY 4TH GEN:

(NOTE - THIS IS A "DRAFT", AND INCOMPLETE. I WILL ADD MORE INFO LATER)

The stock wheels are:

V6:

V8: 16x8.0", 55mm offset, ~6.65" (~6-5/8") backspace

SS/WS6: 17x9.0", 50mm offset, ~6.95" backspace

The offset determines how deep in the wheel well the wheel/tire will sit.

Make the offset too large, and you may have the following problems:
-tire rubs on inner fender liner
-front tires hit fender liners when steering is at full lock
-rear wheel catches on jounce bumper bracket when car is jacked
-wheels "look" too deep in the wheel well, and less aggressive

Make the offset too small, and you may have the following problems:
-outside edge of tire is outside the fender (illegal in some States)
-front tires will rub on plastic fender liners, and inner lip of fender
-rear tires will rub on metal fender lip
-wheels will "look" like they stick out, increase stone damage to paint on side of car, and with narrow tires, will look like "outriggers"

The "look" issue is purely personal. Some people like the wheels as close to the edge of the fenders as possible. Others like them a bit under the top edge of the fender. The numbers below will provide guidelines on when problems MAY start to show up. You have to decide for yourself what you want them to look like.

Wheel diameter will not have much effect on selection of offset. A 9.5" wide wheel will sit in the exact same plane whether its a 16" wheel or a 20" wheel. If you select the tire size correctly, the outside diameter of the tire should be in exactly the same place, whether its a 16" tire or a 20" tire. The one exception is the front steering knuckle. As the wheel diameter increases, you can go to a larger backspace without hitting the steering knuckle. The knuckle slopes "back" from the spindle as you move upward on the knuckle. While a 17" wheel may be limited to a 7.45" backspace, you can use a slightly larger backspace on an 18" wheel.

WHEEL WIDTH:
8.0":

Tire edge outside fender = +13mm
Tire edge slightly inside fender = +29mm
Tire edge matches stock SS/WS6 wheel = +38mm
Tire edge matches stock wheel = +55mm

8.5":

Tire edge outside fender = +19mm
Tire edge slightly inside fender = +35mm
Tire edge matches stock SS/WS6 wheel = +44mm
Tire edge matches stock wheel = +60mm (may have backspace problem with front steering knuckle.

9.0":

Tire edge outside fender = +25mm
Tire edge slightly inside fender = +42mm
Tire edge matches stock SS/WS6 wheel = +50mm

The 25mm offset 9" wide wheels puts the outside edge of the tire slightly outside the front fender. The plastic fender liners will have to be modified to eliminate rubbing. Many are willing to have the tire outside the fender, to get a wider "lip" on the wheel. Here's a link to a thread showing an example of these wheels:

http://camaross.com/forums/showthread.php?t=466696

9.5":

Tire edge outside fender = +32mm
Tire edge slightly inside fender = +49mm
Tire edge matches stock SS/WS6 wheel = +57mm

The most trouble free setup is an offset in the range of 45-56mm. The tires will not rub on anything, except possibly a car that has been lowered 2", when the steering is near "full lock" or if you hit a bump and compress the suspension further.

An offset of 35mm will put the outer edge of the tire barely under the outer edge of the fender.

10.0":

Tire edge outside fender = +38mm
Limited by backspace on front = +50mm
Tire edge slightly inside fender = +55mm
Limited by backspace on rear = +62mm

10.5":
(REAR ONLY)
Tire edge slightly outside rear fender = +44mm
Limited by backspace to rear fender liner (edge of tire shown in next post below) = +56mm

11.0""

-A 50mm offset works best. You may have to hammer the inner fenders, cut the edges off the jounce bumpers, recenter the body over the axle assembly, or roll the fender lips. The outer edge of a 315 tire will just be under the edge of the fender, when you look straight down from above.

-people have used the AFS 36.5mm offset wheels. The outside edge of the tire will be about 1/2" outside the fender, when you look straight down from above.