So I bought Farbin's euroweaves.

[FunfGan]

Very true, Im out of my knowledge in this area, so I'll leave it to those who know what they're talking about.

[nando]

Going too wide on a rim that isn't wide enough for the tire can make the car slower. Even if it "looks" right, it can lead to tread crowning, meaning the larger tire might actually have less tire on the pavement. Plus the weight factor. There was an article about it in Grassroots Motorsports about 6 months ago. It's best to go with the tire width that's optimal for the rim width, even if it's narrower.
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those are nice theories, but you're not going to see that with a 225 on a 7" wheel, especially when it's what the manufacturer reccomends (and even says a 6" will work). maybe if you tried to put a 255 on a 6" rim, you'd have a problem with the tire not working well at all.

also, you really can't change the size of the contact patch. that's determined by the tire pressure and car's weight. the only thing you can really change is the shape (long and narrow, or short and wide). you might have more tire than you need (with the detriment of more weight and cost), but you'll never be able to make it have "less" contact area.

[priapism]

Going too wide on a rim that isn't wide enough for the tire can make the car slower. Even if it "looks" right, it can lead to tread crowning, meaning the larger tire might actually have less tire on the pavement. Plus the weight factor. There was an article about it in Grassroots Motorsports about 6 months ago. It's best to go with the tire width that's optimal for the rim width, even if it's narrower.

Also, I wouldn't use the RA1 for a street tire, they're only really good for 12-14 hard heat cycles. After that they get hard and lose their grip. It's really hard to beat the Direzza Star Spec for an all-around tire good for street and track both. I love that tire, and both my cars handle great on the 205/50-15s on 15" D-Forces.

[nando]

race tires have much stiffer sidewalls than street tires. yes, I've also run 235s on a 7.5 and 225s on a 6.5. neither were "slow" or "squishy".

[FunfGan]

For instance, an undersized 225/45 on a 15x8. So just imagine a tire that runs larger, on a inch thinner wheel.

[FunfGan]

You don't always want the chunkiest tire to run the best lap times/ get the best performance. Sidewall gets "squishy". I my experience, square tires are the best mix of performance.

[Brian D]

Does he want the best performance or does he want whats going to look the nicest in his wheel-well.....

For this place, I'd say about 10%/90% split on that.

http://www.corner-carvers.com/forums/showthread.php?t=46460

Nando, a lot of people would disagree with what you're saying. People with actual experience timing combinations, not just reading off a spec sheet. I know you run your car, you know better. Will it fit, yes. Is it optimal for performance, no.

[nando]

yes. 7" is highlighted, meaning it's optimal for their 225/50-15..

[Jonny Cash]

wait dont confuse me with the average person on this site.
I dont say anything unless I have direct hands on experience with it.
In this case Ive mixed and matched many different ra1's with many different sized wheels. But i understand youre damaged by the knuckleheaded content on this site so I wont take it personal. Have a nice day.

PS.
Yes you can swing it but its not optimal. The HIGHLIGHTED widths are those that are optimal. Does he want the best performance or does he want whats going to look the nicest in his wheel-well.....

[nando]

no, it's not. 7" is actually the wheel width that Toyo highlights in their reccomended fitments.

http://toyotires.com/tire/pattern/proxes-ra1

it's so annoying when people spout crap like that. everyone thinks you need a 9" wheel to run a 225 tire. Just look at what the manufacturer says.

[Jonny Cash]

225-50 is too big for 7" with an ra1. They run wider than your average street tire.

Check out the spece30 images to get an idea of 205-50 on 7" wheel. Even rt615-k (which are even better for dual use, suprisingly pretty good on the track), will run a bit wide- stick with 205 unless its 40/45 AR, then you can get away with 225.

[nando]

lighter wheels, cheaper tires.

[F34R]

you can get RA1s and R888s in 225/50-15 ;)

Came here to post this the RA-1, Nando beat me to it. But they have amazing reviews and are sticky as a mofo.
I am also going to be running a 15" for track weekends. 225/50/15 is the size you want. You can see from Fun's they look a little off. Also planning on RA-1 or the R888.

And why euroweaves? I thought your e30 looked amazing with 17s

[nando]

you can get RA1s and R888s in 225/50-15 ;)

[FredK]

I have always run "undersized" tires because you can't get "extreme" performance tires that have the correct height for an E30.

I run 225/45 R-S3s. They last around 12-15K miles or so with a mix of DD and frequent autocrossing.

Honestly one of my favorite tires were 205/50R15 Bridgestone RE-11s. The sidewall IMO is more communicative than the R-S3s which are rather squishy.