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Discussion Starter · #1 ·
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?
 

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Discussion Starter · #2 ·
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.
 

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Discussion Starter · #3 ·
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.
 

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they do tuck but barely. this is the skinnest adapter i found find because the smallest bolt i could find to sit flush inside these adapter dam near poke out. i went to get my rims installed in the front and they mention how my front rotor have very long center thingy. that it would push my center cap off the rims. i could get spacer but an adapter would do it perfectly. and for the back he suggest i try the adapter first to see how i feel about it if i dont like it i can return it and get my refund and he'll go and drill the rims.
 

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Discussion Starter · #7 · (Edited)
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.
 

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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.
Kurt,

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

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Discussion Starter · #9 ·
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.
 

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If you KNOW that you have the narrow rear axle in your vehicle, the difference PER SIDE between it and an Impala SS is 16mm = 5/8".

To achieve the Impala SS "look" would only require a 5/8" spacer/adapter, but, as already discussed, the absolute minimum for an adapter is 1" (ONE inch), which is 3/8" more than is needed to make the car look like an SS as far as rear wheel position to the body opening.

A 5/8" spacer (as opposed to an adapter) is not a recommended approach.

A 1.25" adapter is another 1/4" thicker than the preferred 1" adapter, and twice the amount needed--and would push the wheel out quite far--too far, IMO.
 

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Discussion Starter · #13 ·
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.
 

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If you KNOW that you have the narrow rear axle in your vehicle, the difference PER SIDE between it and an Impala SS is 32mm = 5/8".

To achieve the Impala SS "look" would only require a 5/8" spacer/adapter, but, as already discussed, the absolute minimum for an adapter is 1" (ONE inch), which is 3/8" more than is needed to make the car look like an SS as far as rear wheel position to the body opening.

A 5/8" spacer (as opposed to an adapter) is not a recommended approach.

A 1.25" adapter is another 1/4" thicker than the preferred 1" adapter, and twice the amount needed--and would push the wheel out quite far--too far, IMO.
Thanks for the info Navy Lifer.I guess i'll look at some 1'' adapters.

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.
I want to see how it looks if I ever see any one with a 1''-1.25'' adapter.
 

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i read the info and it said you have to shave your studs if they dont fit right??

the Only problem would be is when i put my 24'' wheels on i'll have to put new wheel studs back on since i dont plan on using a adapter on my 4's cwm6 not to mention the 4's barley reach my my wheel studs all the way lol.

I guess 1.25 is the way to go.
 

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Discussion Starter · #19 ·
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.
 

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I think you'll be just fine with a 1.25. I just wish i could find the pic.
well its looks great but the rear right rubs and sticks out more then the left rear tire :confused: i think i need a 1'' for the right so that they are same width and no more rubbing in the rear right tire.are Impala and Caprice rear axles off like that? or is just mine?
 
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