In trying to visualize and figure out what offest wheels to buy, I decided to draw a diagram to help me. (new)This does take into account the actual lip thickness or the face of the wheel. The white "wings" are approxamately the thickness of most aluminum wheel flanges.(Note they probably vary from wheel to wheel so go by the inner lip)
I think I read some of the stock wheels are 7"/30mm.
I hope it helps
If you'd like a width/offset added here, let me know.
Here are what tire sizes may look like on wheels: Sidewall height is next to the series...multiply by 2 and add the wheel diameter for overall height.
[This message has been edited by Joe Torma (edited 01-31-2015).]
How about a 7/40 (very common with Konig wheels) and a 7/48 and a 7/50 (common Subaru offsets, which also happens to fit our bolt circle. )
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Originally posted by Joe Torma:
Ask and you shall receive
Thank you sir!
I edited this post to say thanks instead of adding another post. I have asked Cliff to make this a "sticky". It's one of the most useful topics I've seen in a while.
[This message has been edited by Raydar (edited 03-22-2006).]
Added! Blue lines represent faces of stock wheels.
What I'd like to do is make printable profiles for wheels & tires combos that you could put right up to the hub...but not too many people have 50" printers like I do.
I need a little clarification here. How come a 35mm offset on a 8" wheel is different than a 35mm offset on a 8.5" wheel. I would think they would be the same and the half inch would be to the outside.
Offset is center of tire to face of hub nounting surface. When the width increases, it adds 1/2 to each side.
I had 14x6 aluminum with 47mm offset on my 87 coupe that came off an '84 that I had. They probably were not Fiero wheels since they rubbed the struts. The handling was also horrible. After replacing the struts, I replaced the wheels since it could not be aligned with the aluminum 14x6-47mm wheels. I am runninf 17x7-40mm offset with 215/45-17 tires. The handling is great and the 17 diameter is clearing the struts and not hitting the control arms at full turn. Ther 17 diameter gets above the strut mounting that you would hit by just widening the wheels.
One of these days I'm going to throw together a 3D model of the suspension system and brake system so I can check exact wheel clearances in a really cool way
So if i am reading that right i would want a 7" with a 47/48 or 50 mm off set wheel for the front of a 88 ? also what would that off set look like on the back of the 88 ?
Wouldn't that stick out? The stock GT wheels are 7" wide with a 30mm offset. They're about even with the body. Your wheels add at least 1.5" outboard, compared to stock.
Thats why I run a 12MM offset on my 9" rims. That gives me 12.5mm clearence from the tire to the spring. I to would be curious to see a extra line added for the Strut/spring where it would hit the tire. On my 87 GT with 11.25" brakes I have 137 MM from the hub to spring on the strut assy. BTW, Thanks Joe, great idea.
My pleasure. You really have 12mm offsets?
Keep in mind there is maybe 1/2" beyond the width for the lip. This probably varies by wheel manufacturer. The "strut line" may be difficult to place since it may really depend on the tire.
They stick out maybe 1/2 - 3/4" past the edge of the fender. They've never hit the fender yet.
On my wheels the face where the wheels hit the hub is 1/2" off center or 0 offset.
My 9" wheels are approximately 230 MM wide including lip. The tire is even with the outer edge of the wheel, if the tire sticks out pass the wheel it's less than a 1/8" and not a factor because of the design of the spring, smaller top bottom larger on top. Take overall width 230 / 2 = 115 Add back in the offset of 12MM and I have 127mm from the hub to the spring. My spring is 137 from the hub face which gives me 10 mm clearance. This is the widest wheel I felt I could run and not stick out to far because of the fender and still have clearance on my springs and strut package.
The lip on both sides adds maybe 6 MM in overall width, 3 MM on each side.
Offset is measured from the center of the wheel. If the hub is closer to the outside of the wheel from center that is positive offset. If the hub is closer to the inner flange from center that is negative offset (typically Deep Dish Wheels)
That is why there is a difference between the 8" and 8.5" wheels with the same offset. The 8" wheels will stick out further than a the 8.5" wheel with the same offset. I was looking at the 8.5" wheel with a 48MM offset, that wheel should be hitting the stock spring. You would need coilovers to keep that from happening using that wheel.
[This message has been edited by Earl-R (edited 04-03-2006).]
Hmmm....would this be a help? I suppose it makes some assumptions, and the wall would be pulled in for those tires wider than the wheel, but does give an idea on the look.
[edit] moved to 1st post
[This message has been edited by Joe Torma (edited 09-20-2006).]
I knew that my wheel inside the lip was 225MM so I went with a 225 50R16 rear tire. So the tread is the same width as the wheel and does not exceed the width of the wheel.
If a tire sticks out that far beyon the rim (like the 235) wouldn't that effect performance negatively? It may not but it looks like it should. The sidewall isn't well supported anymore and might cause more deflection?
Mind you I have no idea on this topic, it just looks like that to me.
Wow this is a really cool write up. Nice work. So it looks like 235's would be the widest that one could go on the stock 7" inch rims right, or can i go wider. How about the 6" rims off the front of an 88, what would be the widest that i could go on those without effecting the handling??
If a tire sticks out that far beyon the rim (like the 235) wouldn't that effect performance negatively? It may not but it looks like it should. The sidewall isn't well supported anymore and might cause more deflection?
Mind you I have no idea on this topic, it just looks like that to me.
I think you are correct. I think it's easy to see what's too wide for a particular width, and agree it probably will affect handling...at what point that happens I don't know. Tire manufacturers do list a range usually.
Originally posted by hnthomps: Why not add 265 x 50 x 15 to the list. That is what I am running on my stock Chromadora wheels (88 Mera) and they look pretty good.
I really have no idea how wide the Chromadoras are. They just came with the car and have only been off a few times for new shoes. I have a set of mesh rims for an 88 Mera (without tires) and will measure them later when I am home.
Dude this is the best thread I've ever seen on here. Now people can finally see what will and will not fit as opposed to spending hours searching old threads or starting a bunch of new threads. This should be a sticky
I checked the mesh wheels last night and did a rough measurement (OD not ID). The smaller rims were about 7" and the larger ones 8". However, I still do not know what the measurements on the Chromadora rims are.
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Originally posted by hnthomps:
Joe,
I really have no idea how wide the Chromadoras are. They just came with the car and have only been off a few times for new shoes. I have a set of mesh rims for an 88 Mera (without tires) and will measure them later when I am home.
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