Executioner

Found these on ebay and was wondering if they would fit on my 87? I think If I'm reading this right Ill need a 1 inch spacer on the rear hub to bring them in line with the fenders, but how about up front? Any modifications needed there? I saw a black vette 91+ on here with this set up and it looks amazing. I had wide rims on my camaro, and although they grab every damn dent in the road I loved the grip it provided! Thanks in advance!

http://www.ebay.com/itm/One-Rim-17-x...e87c49&vxp=mtr

rodj

Any late model rim with a 50/56mm offset will require a 3/4" spacer ; anywhere on a early car

zr1fred

the 11" wheels fit the early C4's almost perfectly. Most people prefer the spacers when using the 8.5" and 9.5" wheels.

GREGGPENN

That's probably true for the 38mm offset. I bet these may sit too far inboard...but, if pushed out as far as later C4 sit, they'd rub the front fenders on extreme dips.

So I'm also skeptical that a 3/4" spacer is the right amount (for an 11" wheel,,,8.5's and 9.5's yes...I agree).

OTOH, If you've installed 50mm 11's on an early C4, I'll defer to you.

Executioner

Wow, I think I'm more confused now, haha. I wish I could find someone on here with an early C4 that's maybe done it before. shakedown067 is the member on here with this set up on the later C4 in case you all wanna see his, so you know the look I'm going for.

GREGGPENN

Oh I've put (my) 38mm ZR1 rears on all four corners of my 89 as well. (Tried the rears on the fronts, is how I accomplished it). That's how I derived my answer.

BTW...38mm is the correct offset for ZR1 rears. 50mm is the GS offset though they are often made/advertised as such.

50mm-38mm is about 1/2" difference. If, when I put the 38mm on all four corners, you'd moved them inboard 1/2", they would have been PERFECT. But, the early suspension isn't the same. IIRC, it sits another 3/4" further in. So, that's why I'm afraid you'd run into suspension parts w/o the use of spacers -- just like Rodj suggested.

Make sense?

The wheels you linked would fit perfectly on late C4's, but the earlier ones would still require spacers. The only way you wouldn't need them is if you used 38mm 11" wheels on all four corners.

blakngold4life

I have the 17x11's on my early C4, the tires barely stick out past the fender and could be made even by adjusting the camber, these are with the 38mm wheels. That means the 50mm will sit 12mm further inside the wheel well.

Executioner

Okay, thanks everyone. Looks like Ill be getting spacers because I want the deep dish design and the only one available is the 50mm, as far as I can tell. If anyone knows where they sell that style in the correct spacing Ill get them. If not, does anyone know of a good website for spacers? I want the strongest, even if they cost more. Don't want to mess around with durability when it comes to the wheels.

zr1fred

Not trying to get in an arguement, but the 38mm's stick out about 3/4" to 1" on an 88-96 car in the rear (one of the reason's for the wider ZR-1's), and about the same on the front. Are you sure you weren't using the 50mm 11" wheels?

WVZR-1

If your 11" wheels are GM ZR-1 they're not 38mm but 36mm. Relevant? Maybe!! You implied GM I believe when you mentioned "the 38mm wheels". If they're 38mm and not GM, my apologies!

WVZR-1

First of all and likely "irrelevant" for you an 11" ZR-1 offset isn't 38mm it's 36mm.

Second the "generally accepted" 3/4" spacer was calculated "likely" from the more frequently desired application of the 88+ 9.5" (56mm) wheel to the early cars where a 9.5" is 38mm. The difference in the offset of 18mm is .708"+ and since "off the shelf" spacers weren't offered for "application specific" installs some accepted the .75" as "the fit" others optioned to fill the wheelhouse and a 1.0" suited them. Application specific spacers/adapters came much later!

Regarding after-market 11" wheels - the fact that they're advertised as 50mm shouldn't be assumed to be correct, it needs to be measured and confirmed!

Regarding the your desired install: A wheel/tire combination needs to be fit as a "package" with NOTHING assumed. Ideally you should maybe borrow an 11" - 50mm wheel/tire combination and test the fit. Spacers/adapters are available to "tailor" the fit of the tire/wheel package incrementally for required clearances for suspension components and wheelhouse fitments.

You never mentioned tire size so we'll assume 315's. Stand a Sumitomo next to a GY F1 GS-D3 and it appears to be "a miniature"!

You don't mention where you're located - I've got a pair of the 11" that I believe you want - these are "near new" and appear "as new"! These were purchased for a project that I'll never get to. Interested?

redvetttes

Going thru the same thing thing here,

WVZR-1

Although I've never attempted an 11" - 50mm install on an early car(never owned one) this is interesting. My only concern being the suspension interference. Is this something that you've done? With which tires? The inch + additional back-spacing seems it might be a stretch.

I agree that the spacers for the 8.5 - 9.5 was for a placement of the wheel/tire package regarding appearance!

It would seem the fit to the wheelhouse front and rear maybe appropriate. It would be interesting to see an install!

There's so many conversations regarding spacers/adapters here that are "assumed" as fact and I'm sure it discourages some wheel/tire fit combinations. Wheel/tire combination needs to be "one car at a time" with "nothing assumed"!

redvetttes

I have read that the 11 inch ZR rear rims will work without spacers,
they fit on my 86 .don't know it the tires will rub without spacers.
84-86 have a 33 mm offset, 87 and up have a 53 offset,that all I know for sure

GREGGPENN

Yes, I'm absolutely sure. I have 11" ZR1 rears in sawblades. 11" sawblades don't (and never did) come in the GS offset.

Mine do stick out about 1/2". Many people don't like that -- which is why I commented "If... you'd moved them inboard 1/2", they would have been PERFECT." For the 11" rears, clearance is simply a matter of taste. (IOW, both offsets fit). For the fronts, they'd touch unless moved inboard that far.

There has been thread after thread after thread stating how people feel that the 11" 56mm GS offset wheels are perfect for the late cars. Since the early ones sit so much further in, I don't see how anyone could assume they'd be find w/o spacers. In fact, I'm pretty sure I remember the GS offset hitting the suspension on the inside for the pre-88 cars.

Don't take my word for it. Read up.

BTW...I remembered the offsets wrong.
http://www.joby.se/corvette/div/corvette_wheels/

Looks like there's 56-36=20mm difference between ZR1 and GS offset 11" wheels.

Sounds like the advice to double-check the eBay item is a good advice.

rodj

Here lies the point most are missing in their arguments.
There are genuine ZR1 rears (38mm ) and ZR1 replicas that have the late offset

WVZR-1

Yes you did recall the offsets incorrectly and seems you might still! Or it's just a "typo" in your most recent post! Others don't seem to get it either!

The GM C4 ZR-1 11" wheel regardless of style 5-spoke, salad shooter or saw-blade is 36mm and the GM C4 GS 5-spoke 11" is a 50mm. That's only a difference of 14mm(something near 1/2" of back-spacing) and although I always thought that the 50mm would be a "no-fit" on the early car it certainly could have been possible that maybe, just maybe there's enough clearance for the fit. Fred seemed to indicate it is.

Is it? I asked and am still waiting.

If a 36mm is a fit with no interference with suspension components then a 50mm would be a fit with the addition of a 14mm spacer. That would put the wheel/tire package in the same location as your 36mm 11" package. That's fact!

Now if it didn't require the full 14mm to avoid interference with suspension components then you could move the wheel/tire inboard for a more desired fit! Tire selection would be important also, the Sumitomo is substantially smaller than most 315's which would effect interference!

I've no "first-hand" knowledge but if you haven't actually attempted it you don't either!

Now before you mention my comment of 1"+ backspacing earlier, that reference was the difference from a 9.5/38mm Z51 wheel for an early car vs that of an 11"/50mm GS.

GREGGPENN

Yep, I was closer the first time. (After having more time to look thru my link.) In my first post I said 50mm and 38mm when it was 50 and 36mm. 2mm is inconsequential to the debate, but certainly a valid correction.

Beyond that, I believe my other statements are correct.

The other thing to consider is you really don't want to try any adapter thinner than 3/4" billet. (IOW, at least 19-20mm is required). Thin spacers are sometimes used (with longer studs), but not typically recommended. For non-racing applications, you can try spacers if you keep them thin enough so the center bore remains partially on the center hub. But, I'm 99% sure that's thinner than 14mm.

Again, 50mm is what's considered best for a 4-wheel 11" application on late cars. Early hubs sit further inboard and I'm also 99% sure that Rodj's comment about needing 3/4" spacers (adapters) is correct. That's because your choice is really 3/4" or nothing!

If you don't offset that 3/4", the issue will be whether you rub on the inboard side. And, tire size/brand could make a difference. GY are a bit wider. OTOH, I wouldn't care for how far inboard a later model wheel would look on an early car -- including 11". So, even if they didn't rub, I'd think you'd want adapters. (Plus, I really thought I'd read about 50mm 11" wheels contacting the suspension on early model cars.)

FWIW, adapters have 5-studs sitting between 5 bolt holes. They bolt up to your hub and leave 5-studs on which to mount your wheels. If too thin, the studs will pull out and break the adapter. Spacers just take up the distance between the wheel and hub -- requiring longer wheel studs. If pushed out so far they don't contact the center hub, they can become non-centric (wobble up/down). I believe that's referred to as run-out.

redvetttes

That is what scares me breaking studs
I have had wagon wheels bolted up to my 1986 (36 mm) back space. They don't rub any parts. There are no tires no the rims either

GREGGPENN

36mm is the offset, NOT the backspace! There's a difference.

Offset is the distance your mounting surface is "offset" from the center of the wheel. Backspace is the distance from the mounting wheel surface to the inside edge of the rims.

In practical terms, an 11" wheel has 3/4" more backspacing than a 9.5" wheel. So, it will extend 3/4" closer to the suspension. And, that's if/when both have the same 36mm offset. (or 50mm offset, or 56mm offset). When offset -- between two different width of wheels -- is the same, the extra width will be divided equally between inside/outside.

Make sense?

BTW...ANYTIME you go to longer studs and are worried about stud breakage, use ARP studs. IIRC, they are rated at something like 120,000 PSI.