Rubbing issue with 8 inch snowflakes

[78freebird]

Help, I just installed 8 inch snowflakes with 255x60R15 T/A radials and i am getting a scraping noise in the rear, any idea what my issue is?

[81Blackbird]

Hmmm!  I got 285 x17 on a 9 inch rim with 5.5 inch backspacing.  The only problem I had was the E-brake cable rubbing on one side.  4-wheel disc.  I had to do a little mod on that.
Have you taken the wheel off and looked for a rub mark on the inner fender?  A scraping noise may indicate the inside part of the rim is hitting something.  Take the wheel off and
see if you find any evidence of rubbing / scraping.

[Wallington]

x2 that isn't a massive tyre or rim by any stretch, shouldn't have issues based on that choice.

I'd be checking the basics, bounce the rear of the car, see if exhaust or similar is loose or hits. Could be worn out suspension with too much travel, up and down and sideways from long shackles and worn bushes, soft shocks, exhaust that's moved. The tyres and rims shouldn't be an issue on themselves, not like an unknown rim used and found to be wrong offset and rubbing on inner fender lip or shock mount plates. As mentioned, look for rub marks, anywhere extra close to contact that changes when car bounces around, rim off and inspect for marks or where rubbing.

Likewise, had 275/60 R15 and 285/40 R17 and nowhere near anything, with standard and then lowered suspension.

[tinpusher]

With the limited information, I would start by placing some Jack stands under the rear axle, spin the wheels and check the brakes, sometimes they will make a grinding noise if you have some rust accumulation.
If not you can idle the car in drive or reverse to try a duplicate the noise… my 2 cents.
The other members provided excellent suggestions for diagnosing the issue.

[Wallington]

I'd expect most ppl would stop and check the moment they heard or felt a rubbing or grinding noise, rather than simply continue, then post about it later on fbook or a forum, never to return. Most ppl.

[Oldsschool79]

I recently installed a Pypes x pipe system with Flowmasters, my right 5x8 rubbed the tailpipe. The 2.5 " system didn't leave much room to spare. Made some adjustments and readjusted the pipe's bend with heat and all fixed. Hope it helps.