[Firewood]

Thanks to Google archiving, I found this one today!
almost every week, someone has a question about running adapters on a particular wheel.

It can be mighty dammed confusing! But follow along with me and maybe we can make sense of it all.

Lets say you've got a corvette wheel, and its a 18 x 9.5 with a +55 offset. That's hypothetical, the make them in a variety of offsets, be SURE to check yours thoroughly before you begin.

If you have an SS, you consult the backspacing chart:

http://www.impalassforum.com/vBullet...d.php?t=146045

Quote:
Front:
18X8 / 4.5BS
18X8.5 / 5.0BS
18X9.0 / 5.5BS
18X9.5 / 6.0BS

Rear:
18X8 / 4.0 BS
18X8.5 / 4.5 BS
18X9 / 5.0 BS
18X9.5 / 5.5BS
18X10 / 6.0BS
18X10.5 / 6.5BS
Then consult the offset to backspacing calculator on this site:
http://www.autolounge.net/calculators/tirespacing.html
The vette wheel has approximately a 7.41 backspace.
We need to be 5.5 on an SS
So we need a 1.91 inch thick adapter! That's not hard to understand after all.
In reality, most people use a 2 inch thick adapter on vete wheels... but the offset of the wheel is the most important info to have.

Ok, lets say you're like this guy:

Originally Posted by SSick96 View Post
Looking at buying some 22 x 9.5 American racing torq thrust M wheels from someone locally. here is a link with all the info on the wheel:

http://www.americanracing.com/browse_ar.asp

The guy told me they are a 5x115 lug pattern and were on a dodge charger. On the website it says they have an offset of 18 and the backside is 5.96.

Could someone who knows more about wheels let me know if these will work on my car with adapters? If so what adapters do i need and where can i buy them? a link?

I have a 96 BBB impala ss. stock height. Please let me know if these will work with adapters and if there are any problems I may run into. Thanks in advance.

The thinnest adapter most builders will make is 1 inch thick. The studs will interfere with anything smaller. If you could consult the missing big wheel sticky,

For 22" wheels, keep the offset +18 to the +10 range. We've seen JAYO run 22x10's on all four corners with a +15 offset, and no rubbing. Again, lowering is a factor to, so keep it towards the higher numbers.

and then convert inches to MM, you'll find that even a 1 inch adapter at 25.4 mm thick, backs your offset down to -6.5. UNACCEPTABLE! They would very likely push out too far and rub the hell outa something.

Here's a great calculator for conversion:
http://mg-jewelry.com/mmtoinches.html

Remember to always get adapters that are HUB CENTRIC to the intended wheel, and to your car. It usually cost a bit more, but it's worth the effort for added strength. With non hub centric, the wheel is supported only by the studs. Hub centric shifts some of the load to the hub. DO IT.

There are hundreds of e-bay vendors selling non hub centric adapters. Resist. Get good stuff. They're only holding you rims on, right?

 

[Firewood]

Where to buy adapters

Lots of forum members have used this guy
http://www.wheeladapter.com/
If you talk to him right, he's very helpful, and has even sent a test adapter out to people before he made a set just so they could make sure everything fit. But forum member had a very bad experience with him. So YRMV!

These people actually build adapters for many other vendors. So they are very, very good. Not so cheap, though. I HAVE used them.
http://www.motorsport-tech.com/

These are the ONLY Firewood endorsed vendors. For whatever that's worth.

 

[Firewood]

Here's another example.

i have a set of camaro wheels i wanted to know if they fit on a 96 impala ss?

From a quick read the Camaro rims use a 5x120mm bolt pattern
Our cars use 5x5inch - so they will not bolt up directly

The rim sizes that go with those tires are for the SS model and are 20x8 ET 35 front and 20x9 ET 40 back.

If we covert the offset to backspacing using the above linked chart, the front wheels have 5.87 in of backspacing. Ideal desired spacing is 4.5, so you'd need 1.37 inches of adapter. 1.25 adapters are available off the shelf just about anywhere and should work just fine.
For the rear the calculator says you'd have 6.57 backspacing. You need 5.0 on the rear, so you need 1.57 inches of adapter. This again is a normal, on-the-shelf adapter size, so they should be easy to find.

As always, I recommend that you spend the extra cash for custom built, hub centric adapters made to your specific specs.

 

[Firewood]

I would get them redrilled so they can tuck. How thick of an adapter is that?

 

[Firewood]

As noted in
http://www.impalassforum.com/vBulletin/showthread.php?t=239710
Ls1caprice wants to know how thick an adapter to run to make his wheels work.
They are 20x8.5 and 20x10's with a +35 offset. a 10" wheel works perfectly with about a +15 offset, so we need an adapter 20mm thick. Plug that into the MM to inches calculator and it tells you your ideal adapter should be 0.7874 inch thick. The problem with that is no one will build one that thin.

The thinnest you can get is is 1 inch. That translates to a 25.4mm shift in offset, leaving you with about a +10. This would work just fine on the front, and probably be ok on the rear, too, but you'd want to do a bit of measuring.

Convert that to backspacing and you get 5.89 inches. that's less than 1/4 from being perfect. For an SS.

Dammit! I just realized you have a caprice. The caprice rear axle is a full inch narrower (iirc) than an Impala. So you could do a 2" thick adapter for the rear and be in business.

 

[Firewood]

Kurt,

Caprice 9C1 is narrower, but 94-96 Caprices with B4U--and there are many--have the same axle width as the Impala SS.

Wow, how bout that. Don't think I've seen that.

 

[Firewood]

Thank you, I've been waiting for someone (you) to post the exact difference in width.

A few months back, someone posted a caprice with SS wheels and 1.25 (1-1/4 for the match challenged) adapters, and it actually looked just fine. Maybe I can find it with our not so good search function.

Ok, I tried. Cant find it.

 

[Firewood]

are these perfect for a 96 Caprice?
http://cgi.ebay.com/ebaymotors/CHEV...Q5fTruckQ5fPartsQ5fAccessories#ht_1807wt_1167

yep, that's a winner.

 

[Firewood]

I think you'll be just fine with a 1.25. I just wish i could find the pic.

 

[Firewood]

Here's an adapter calculation for an unnamed forum member. He's looking at a 22x8.5 wheel front & rear. To keep the front and rear both flush, he'll need wider adapters for the rear. In this case, it will be better to work with backspacing. The wheel he wants has a +38 offset. Using the offset to backspacing calculator, you have 6.25 (6.24 TO BE EXACT) inches of backspacing. According to the chart,

Quote:
Front:
18X8 / 4.5BS
18X8.5 / 5.0BS
18X9.0 / 5.5BS
18X9.5 / 6.0BS

Rear:
18X8 / 4.0 BS
18X8.5 / 4.5 BS
18X9 / 5.0 BS
18X9.5 / 5.5BS
18X10 / 6.0BS
18X10.5 / 6.5BS

A 1.25" adapter on the front and 1.75 on the rear would set it just right. I'd bet you could even do a 2 inch on the rear.

 

[Firewood]

Here's a few examples of members using adapters to make something fit that otherwise wouldn't:

You might know this guy. He's a pretty big deal around here:

Staggered Axis wheels that were NEVER intended for a b-body. And they look like they should have been built that way.

And even though he doesn't want them anymore:

His is a little different in that He's running a thicker adapter on the rear to minimize the fender gap.

Now someone go find a pic of Black Krptonite.

 

[Firewood]

Here's a new one:

Theres a set of wheels I'm interested in but Im going to need adapters because their bolt pattern is 5x112, 20x8.5 front with a 2" lip and 25mm offset, and the rears are 20x11 with a 5" lip and 35mm offset. Do you think these will stick out past the fenders on an Impala?

Given that the thinnest adapter you can safely run is 1 inch thick, whick converts to 25.4 mm, That would bring your front offset down to -.04, which close, but acceptable.
On the rear using the same adapter puts your rear at +9 which should be ok, but when you run an 11" wide wheel, the fit very tight. You may have to play with the rear specs a bit.

Center your frame!!

But yes, you can do this.

 

[Firewood]

Does anyone have pix of 1" wheel adapters on a 9C1 running stock SS wheels? I imagine that I can roll the lip if needed.

You won't need to roll the fenders.

 

[Firewood]

I'm just wondering If it'll look stupid with the wheels being pushed too far out. But hey, I'm sure it'll look better than the pushed in look it has now

Won't look stupid. It would just look like a stock ss rear. Even the 1.25 adapters work well and look fine.

Baby-d, post a pic!!!!!

 

[Firewood]

No rub, right?

 

[Firewood]

Here's another adapter sizing I did for someone:
http://www.impalassforum.com/vBulletin/showpost.php?p=2470895&postcount=13

 

[Firewood]

I'll have to do the math on this tonight, but at a glance, I think your offset is too low for adapters. I think you're gonna have to use spacers. Don't panic!

 

[Firewood]

Since that stick was created, its been discivered that our cars have quite a bit more tolerance for backspacing and offset. The 20x10 Eagle 225's used by several members with lowered cars, have an offset of +2. Which is about 5.57 inches of backspacing. So there is some room for error in the recommended specs at the top of the page.

If your wheel has 6.8 inche BS, and the recommended is 6.5 inches (see chart at top of section) You may not need a spacer at all. a 1/4 inch spacer should give you a good fit, if you need it at all. Have the wheels redrilled and have the center bore opened to 78.1 and you should rock.
That's the great thing about BMW wheels, they usually dont need adapters.

 

[Firewood]

bump.

 

[Firewood]

Sometimes I have to use that stickies, too!

I have a set of 18x8.5 wheels with a +13 offset sitting in my basement from another project. They're 5x120, so I'll have to use adapters or redrill.

Using the above calculations +13 converts to about 5.25 backspacing...And a 1 inch thick adapter makes it 4.25...And that's not likely to work at all.

But just to be sure I'm gonna take one to work and slide it under the car and measure the space btween the mounting pad and the drum. I might get lucky... but the math says no.

We shall see.