psycko069

iTrader: (2)

Im looking for information on putting 275 tires on a 9 inch wide rim. The car is pretty much exclusive to Autocross and Track days. Right now I am running a 255 on 9 inch wide RPF-1's. I want to bump to a wider tire without having to come out of pocket for new rims. So the questions are, is it worth it? Any fitment issues/rubbing? Will there be too much roll in the sidewalls? Anyone doing this? I have heard its been done with success, but haven't heard or seen first hand from anyone. Pictures?? Thanks in advance....

heel2toe

iTrader: (41)

Is there a specific tire you are looking at? What are the specs of your RPF1's? 17's or 18's and whats the offset?

The simple answer is yes, it can be done. As far as what's involved to make it work as well as the optimum size, well that depends...

psycko069

iTrader: (2)

I have been running the BFG R1S since it came out. Love that tire. Better wear than the A-6, less drop off in grip due to heat and cheaper. Sorry that I did not specify in the original post. The rim is a 17 inch, and IIRC the offset is 35. My pressures range between 47 and 50 depending on the track conditions...

MinusPrevious

iTrader: (3)

If interested

17x9 +29 / 275/40 Nitto NTO5

heel2toe

iTrader: (41)

IIRC the BFG's run quite wide. I recall recently seeing a comparison between a 265 BFG and a 285 Hoosier and they were about the same. These were both mounted on 18's but assuming its consistent the 275's may be more like 295's Have you looked through this thread at all? https://www.evolutionm.net/forums/mo...test-tune.html

What sizes are available for the 275's? in 17's? I know the A6's have both a 35 and 40 sidewall. Assuming they do indeed run wide mounting a "275" on a 9" rim may be ambitious. It may fit but might be too pinched and roll over too much on you.

Neal@tirerack

iTrader: (25)

The 275 will fit fine on a 9" wheel. May need a change in camber and/or fender roll depending on the wheel you use. I've seen some people get away without both but it depends on how the car is set up.

psycko069

iTrader: (2)

Thanks for the replies. Neal, IIRC the only 275 for a 17 inch wheel is a 40 series sidewall. Correct?

heel2toe, I have not seen that write up that Jeremy did. It was a good reference as to what I have experienced as well. As far as sizing, he was on an 18 inch rim. Tire Rack published the measurements for the 275/18 as 10.9 inches wide and a diameter of 25.4 inches. For the 275/17 it looks like a width of 10.9 inches and a diameter of 25.5 inches. I may have some rub issues then? I have no fender mutilation yet, although I think its going to end up happening. I may be able to get away with it with some camber changes... I dunno, should I make the move and pick some up??

psycko069

iTrader: (2)

Oh and thank you for the picture. Happy to see that others are fitting these meats in there...

Tevenor

iTrader: (9)

I ran V710's in 275/40/17's on +35mm 9 inch rims. A bit pinched but nothing to severe. Ran about 3 years of autocrossing in AS and SM on that setup.

heel2toe

iTrader: (41)

Jeremy- A 275/40 is a tad tall which could make it tricky. Not to say its been done but its not solely about the width which you seem to be aware of. As far as fender rolling/pulling is concerned, it's the rear that you will have to worry about so I would make sure to address that.

What is your current alignment? More negative camber helps tuck tires under the fenders but being that this is purely for performance, be very careful dialing in more negative camber. I get a sour taste in my mouth when people tweak their alignment to fit wheels and tires. By that I mean the whole stanced crowd running -4 degrees camber in the rear.

If your goal is to get more rubber under there in order to improve the handling of the car dont go against that and get a crazy alignment to fit them. Judging by your signature, I'd venture a guess and say you're not one to do that.

EvocentriK

Wow surprised at the support for this idea. I didn't even want to run 265's on a 9" wheel as IMO it feels sloppy. I run one size under, so currently running a 245/40 on a 18x9" wheel. Depends if you'll be expecting good cornering feel and precise steering, if you just want as much traction as you can get in a straight line it might be fine, but if you expect to corner at speed, yeah, it's going to feel real mushy compared the right size or one under tyre.

MRLancer05

iTrader: (2)

What wheels are these?

MinusPrevious

iTrader: (3)

Advan RGII 17x9 +29

heel2toe

iTrader: (41)

As with any wider tire, turn in will become sloppier, and heavier as the sidewall will flex a little more not to mention the fact that the tire will weigh more.

Now this is solely my opinion so take it with a grain of salt, but I believe that the more rubber you can stuff on there the better off you are. I dont mean 285's on an 8" wheel but if the tire isnt too pinched then the benefits from the increased ultimate grip will outweigh the decrease in turn in response.

Our cars already have such unbelievable turn in with the quick steering rack so if that is numbed a little it is not as significant.


I believe they are Advan RgII's

EDIT: The man ^ has spoken, I'm a little too slow

MRLancer05

iTrader: (2)

Thanks Guys, I really like those.