P325/50R15 Nitto NT555RII 112V Rear Tires

[Bean]

Has anyone tried these tires and if so have they needed to make any changes to body work or off set to get clearance for stock Butler body?

[eschaider]

On balance, that is probably a good tire. It's dims say it s a 27.8 inch tall tire with a section width of 12.8 inches. The actual tread width will be a bit less maybe an inch or so.

When I do a quick search of Tire Rack they do not show the tire — doesn't mean it is not available. My guess (only a guess) is the tire is probably a 330 wear factor tire. At 70 mph with a .82 overdrive you will be running about 2200 rpm at 70 mph in fifth gear with a 3.55 R&P.

My biggest concern would be the ability to maintain traction in lower gears and the ability to negotiate turns during spirited driving without losing traction and smoking the tires or spinning out of control — both bad albeit in different ways.

I would look for minimally a much softer rubber and or a slightly larger diameter. Worthwhile remembering, the softer rubber glues the car to the ground better but wears out quicker also.

[Tom Wells]

Bean,

The RII is a track tire with a wear rating of 100. Here's the "horse's mouth": https://www.nittotire.com/competitio...g-radial-tire/

You could make a cardboard template - basically a circle with the bolt pattern holes in it, using the tire OD on the web site. Then put it on instead of a back tire and start measuring side-to-side.

For both lateral and radial (no pun intended) clearance estimates, don't forget to account for the full movement of the rear suspension from full droop to full compression.

It's a little work but might save you a bunch of work and $$ if you do this.

Hope this helps,

Tom

[Bean]

I figure if I increase the diameter of the cardboard template by the amount of suspension travel, mount it as you instructed, I can measure side to side and at the top and get a pretty good idea if these tires will fit with the stock setup. These tires are 1" wider than what I'm running now with the same diameter.

Thanks Tom. You're my new engineering Guru.

Bean

[Tom Wells]

Bean,

Please don't give credit where none is due LOL

Don't forget about the rear wheel offset too!

Here's another reference on fitting wheels: https://www.racingjunk.com/news/how-...-tire-fitment/

Take your time to understand the measurements and you'll likely be successful.

Enjoy,

Tom

[Tom Wells]

Bean,

Just reread your post; I missed the reference to the present tires. Sorry...

If you're planning to use the same wheels and the only difference is the width then a half-inch added on the inside and the same on the outside should work.

If you can find a bit of 1/2" cardboard or whatever that could be taped inside/outside to the existing tires that might give you a pretty good idea of what to expect.

Most tires have their widest measurement between the tread and the rim (usually closer to the tread.) Maybe the web site gives you enough data?

Tom

[Bean]

Great ideas/link Tom. I appreciate your help with this. Thank you very much.

Bean

[Tom Wells]

Bean,

Just one more thing that floated to the top overnight: make sure your wheels are wide enough to accommodate the wider tires. The Nitto web site should give you the minimum rim width for their tires.

Tom

[spdbrake]

It'll look great. Ahh to be 17 again...
They still sell air-shocks.

[joyridin']

I think you are going to have a rubbing issue due to the diameter. I had 295/50/15 on the rear, which is about 26.5" tall and if you hit a bump, the tire would hit on the inside of the fenderwell toward the front. You can jack the rear up to stop it, but then it looked like that Ford in the picture above. I have 315/35/17 now and the width is 12.4 with no issues at all. I probably could have gone an extra 1/2" on the outside and maybe a bit more on the inside.

[Bean]

Hi joyridin', When I got this car it had 305/50R15s on it with no problem. I think they were the original tires that Butler put on it as they were dated about the same time the car was built. Could the body of your Arntz be different than the Bulter's? Thanks for the heads up. I'll pay special attention to that inside fender well toward the front. According to the specs I get the Nittos are 0.8" wider and 0.8" taller (diameter) than those originals. Cars in storage now so not able to do any of Ted's confarbulations at present but 0.4" on each side and 0.4" on top doesn't seem like much.

Bean

[Bean]

Sorry!!! That should read Tom's confarbulations!!!

Bean

[Tom Wells]

Bean,

No problem - I've been called way worse LOL

Tom