My wheels are 17x9 and have a +24 offset and 6" backspacing and I'm using 1" adapters all around. Since I have 275 rubber all around the front tires rub the plastic fender lining and at full right lock make a lovely grinding sound against the a-arm. I'm not worried about them rubbing the plastic, but I don't like the tire hitting the a-arm. The two people I talked to before I bought these wheels both used spacers and they said the tire didn't rub. Now that I put on the C5 brakes the front wheels are moved out another .3". So, if it is safe I want to replace the 1" adapter with a smaller spacer to try and eliminate the rubbing. I'm talking about a good spacer designed for one bolt pattern, not universal cheap crap. What would be the maximum size spacer that is safe to use?

 

Technically no spacer is "safe". Spacers are a bandaid fix for improper rim spacing.

 

you need to buy skulte adapters not spacers

 

Billet spacers like the ones Skulte sells are safe enough. You'll overcome traction long before you'll break two 3" diameter chunks of billet aluminum on a street car.

Right now, your running ALL your power through a single thin walled 3" driveshaft and you haven't broken that.

You might break them on a monster truck though.

I think 1.25" is the narrowest Skulte sells, unless your wheels are machined for stud clearance.

 

The smallest adapter I've seen is 1" and that's what I'm running now.

 

I think that the important thing is how many threads do you grab with the lug nut.. I would not go long term with less the five full turns. And I would not go more than 1/2" spacer. Its best to use adapters if you can. I am using 1.75" adapters on the front and 2.0" adapters on the back..... These adapters have there own studs. The adapters bolt to the rotors, then you bolt your wheel to the adapter.

 

As mentioned above, adapters are acceptable. Spacers are not for the above reason.

By the NHRA/IHRA rules for wheel studs which can be considered a safe rule to follow on the street. The stud must protrude into the hex portion of the nut no less than the thickness of the stud.

Simpler terms, if you have 12mm wheel studs (about 7/16"), there should be a minimum of 12mm extending past the surface of the rim or wheel nut washer if that style on nut is used. If you use wheel spacers and the wheel studs are not extending past the surface of the rim, then it's considered unsafe even if you use a rim/wheel nut style with a shank which extends into the rim such as Weld Draglite or Prostar rims.

 

which is why i run the 3" studs with my welds and dont use the stupid ss/t lugnuts

 

Then I guess there's nothing I can do about this problem. If I take off the adapter and just use the .3" gained from the C5 rotor the wheel will probably hit the strut and tie rod, a small spacer is unsafe, and the 1" adapter I already have lets the tire rub.