Modern OEM Wheels to fit a C3?

[melssen]

Are there any modern OEM lightweight wheels that would fit a C3? I am looking for a 16" or 17" wheel with similar to OEM back spacing and offset. I am having trouble finding anything other than the bolt pattern. Thanks for the help.

 

[BBShark]

Lots of guys use C4 wheels on C3's. You have to use spacers, you will find that most modern OEM wheels will need spacers.

 

[melssen]

Maybe I am thinking about it wrong, but it seems to me using spacers may be hard on your bearings. Kind of like holding a weight close to you compared to your arm out strait.
Am I off base? If so, any idea on the spaces I need? An adapter as well? I thought there was a slight difference in bolt pattern between the C3 and the C4 (and most modern cars for that matter).

By the way BB Shark, I am going to be trying out that Jeep Steering box you put in the downloads. Got one for $30 and am having a machinist friend at work make me the adapter plates. I am pretty excited not to be weaving down the road anymore.

 

[mrvette]

Jeep box fixes lotsa problems for sure....

15 years ago, I put a set of cheep '92 vette wheels on my '72, my '72 has mild later shark size flares , so in the back the 275/50/17 Nitto 450? and in front 255/50/17 is the tire size....now I use VBP 2.5 inch thick ADAPTERS....that puts the wheel centerline at just about where it was stock, so to move the ebrake cable from behind the tire to behind the rotor like I did, OR to the top of the arm the way most guys seem to like it....

it's one of the first updates I did to this shark, back when....

:bounce:

 

[BBShark]

Maybe I am thinking about it wrong, but it seems to me using spacers may be hard on your bearings. Kind of like holding a weight close to you compared to your arm out strait.
Am I off base? If so, any idea on the spaces I need? An adapter as well? I thought there was a slight difference in bolt pattern between the C3 and the C4 (and most modern cars for that matter).

By the way BB Shark, I am going to be trying out that Jeep Steering box you put in the downloads. Got one for $30 and am having a machinist friend at work make me the adapter plates. I am pretty excited not to be weaving down the road anymore.

As long as the tire is basically in the same position as stock. there will be no more load on the bearings. People used to eat up bearings with "deep dish" wheels that moved the tire away from the bearing but you don't see that look much these days.

Post some pix of the Jeep conversion and if you have any questions, you know where to find me.

 

[melssen]

That makes a lot of sense.
Forgive my ignorance, I am relatively new and have not done nearly enough research. I will look around for some used lightweight wheels (light on budget) that fit the C4. I will probably post the wheel specs and hope some people can help out with if they are a good fit and what kind of spacing I need.

 

[mrvette]

LATER C4 wheels are the more preferable because they are 17" and can vary between front/rear as to width....from 8.5? to 9.5 and even 11 in the rear, IF they are ZR1 size rims...gotta be some exception to that very general statement....but I like 17" rims with 50 series tires of appropriate size because they are more popular and cheeper than the early C4 sizes in 16" rims...

so for the 9.5 rim, that seems to be the widest you can go in the rear without altering the geometry of the t-arms, and when doing that any stock-ish sway bar will be too long and rub the tire my car for instance is roughly 1/4 inch between the t-arm (having move the ebrake cable mount, remember) and the sway bar....next point is the front up kick to the frame....

to keep same/damn close centerline offset and therefore bearing/suspension loading to the stock specs is the goal,

unless you go ape **** like some guys here and then the lid's off and the cats are running....

:bump::devil:

 

[DC3]

OEM wheels might be kinda tough to get a good fit in the sizes you want. I'm running aftermarket 17x8 TT IIs (4" backspacing, -12mm offset) and really like them. They weigh quite a bit less than the rally wheels I took off.

Have you looked at the ZR1 style wheels that Eckler's and others sell for C3s? They are 17 x 8 and supposed to be the correct backspacing. OEM look with the right fit. Don't know about the weight. Here's a link:

http://www.ecklers.com/wheels-and-tires/custom-wheels.html

DC

 

[groovyjay]

How-bout BMW wheels? Or wheels with BMW bolt pattern and correct offset?

 

[melssen]

"How-bout BMW wheels? Or wheels with BMW bolt pattern and correct offset?"

-- I will have to check those out. I live in Miami area and there are always BMW wheels being sold for aftermarket wheels. I am sure modern stock BMW wheels are far lighter than the old steels. thanks.

 

[melssen]

Does anyone know if a 40mm offset to much on a 7.5"wide rim?

 

[DC3]

Don't know but here's a good wheel/tire size calculator. You can compare your proposal to the factory setup to see how they differ.

http://www.rimsntires.com/rt_specs.jsp


DC

 

[melssen]

Thanks for that. The website has the following data for a '75 vette:

OEM tires: 225/70-15 (695x225mm).
Bolt pattern: 5x120.65 (5x4.75).
Offset: -15 to 0 mm.
Tires up to 715x245mm (front). Rims up to 22x8.5" (front).

So it looks like a +40mm is far to much offset. Now I have some more good data to help with me cheap wheels hunt.
thanks

 

[melssen]

I found some Aluminum Wheels from a c3 (a option some years) are these wheels much better than the steels? I assume lighter, but enough to add to anything but looks to the car?

 

[mrvette]

I found some Aluminum Wheels from a c3 (a option some years) are these wheels much better than the steels? I assume lighter, but enough to add to anything but looks to the car?

AFAIK the most a C3 ever came with from GM was a 15" wheel, and 8" wide at the widest...

to put anything wider, you need modify the rear ebrake mount at a minimum...

:beer:

 

[MYBAD79]

you're talking about the stock 15x8 aluminum wheels off a 78-82 model ? these are not really all that light but they look pretty good IMO....

performance will be a lot better with 16 or 17" wheels and modern tires.

best compromise between performance and fitting the budget is probably some 17x8 American racing TT2s (or knockoffs, Ebay) with 4" BS (0 offset) and 255-45-17 tires....

 

[DC3]

best compromise between performance and fitting the budget is probably some 17x8 American racing TT2s (or knockoffs, Ebay) with 4" BS (0 offset) and 255-45-17 tires....

I agree although I went with 235/55-17's. They are slightly narrower than the 255/45's but over 1" taller. They were the correct height for my speedometer to be accurate and I like the way they fill out my wheel well better.

DC

 

[mrvette]

best compromise between performance and fitting the budget is probably some 17x8 American racing TT2s (or knockoffs, Ebay) with 4" BS (0 offset) and 255-45-17 tires....

I agree although I went with 235/55-17's. They are slightly narrower than the 255/45's but over 1" taller. They were the correct height for my speedometer to be accurate and I like the way they fill out my wheel well better.

DC

For speedo calibrations, you have to use GPS/Garmin ....all else is ********....

and I never did figger out why..just IS....I choose my Garmin over all else...


for one thing, NOW my speedo is good to 80 mph indicated and doing 78, at 100 it's only really 94....

all slower speeds are right on....so go figger...

:hissyfit:

 

[greg75vette]

That could be error introduced by tire slip.

 

[mrvette]

That could be error introduced by tire slip.

That's what I would think also...and did, but someone who's knowledge I respect, shot that down....so I dunno....

:bonkers::flash:

 

[gdh]

How-bout BMW wheels? Or wheels with BMW bolt pattern and correct offset?

What yr. and model BMW are those rims from. They look like a combo of BBS & CCW rims.

 

[gdh]

Found some locally.