jsutto13

I have a set of Kosei K1s that I want to put 225 R-Comps on for Track Use. Will a 7" wide wheel hold the tire geometry well enough for track duty?

WonTon

iTrader: (17)

just give them to me! then write it off on your taxes hehe.

Jfornachon

iTrader: (23)

What tire? I am shure you can put them on that rim. Have afun doing so and then trying to get them off is going to be more fun. What is recommended by the manufacturer? Do some research. I have been told that 205's are to wide for the 7" rim. Do some research.

Have a great day,
Jared

curly

iTrader: (25)

Yes it'll be fine, 7" is the minimum width tire companies suggest for 225. Or at least that's what I remember from when I researched it, it's been a while. I had 225 toyo proxxes 4's. They worked great and lasted a long time with 5-6 track days, and 20-30k street miles. The grip with them compared to my 185 stock tire/wheel combo was amazing, however there's a noticeable amount of "tossability" lost with the squishier sidewalls. 8" is definitely better but 7" will be fine.

jsutto13

curly, do you think I will be losing some max grip because of the enlarge sidewall "bulge" caused by the 7s? I'd be curious to know if 8s would help my cornering speeds with tires held constant. I would assume 8s would allow the tires to roll less...

Jfornachon

iTrader: (23)

Jsutto13 you are correct. 8's will be a much better size for that tire for all the reasons that you listed above.

Have a great day,
Jared

curly

iTrader: (25)

Maybe, you're never going to know though. Not $600 in new wheels worth at least.

miatamike

I've had 225 on 15x6.5 Never had any issues.

NA6C-Guy

iTrader: (1)

Surely you lost some turn in response or feel some loss of "tossability " like Curly said. 205's on my 6.5'' wheels look and feel too wide, I can't imagine 225's. But I guess sidewall height is the biggest issue probably.

hustler

iTrader: (6)

They will drive like **** and feel like you're driving on balloons with tons of sidewall roll...but it works. After 225's on 15x9, I'll never go back.

my97miata

So, will there be any rubbing issues if 15x9's were used with 225's in the rear of a 97 model? Or will the rear fends need bending?

hustler

iTrader: (6)

yeah, you need to roll fenders big time for the 9's...but its soooo worth it.

UI Vandal

Id say just save money and get 205 for your 7". Better width match, less rotational mass. Or you could save up, sell your wheels and step up to that 15x9 225 combo (unless you are class restricted). Mmm, meaty!

my97miata

I plan on adding a turbo in the future, looking at around 225 WHP and possibly more later on. So I'm a bit concerned that 205 width tyres may not be enough.

sbrian2

iTrader: (12)

Yes they will work fine. I have mounted 275's on a 6" wheel before for a friend with and Integra Type R.

chris101

iTrader: (7)

We've been using Hoosier 225 45 15s on 15x7 rims for 3 years now for NASA Time Trials (have 6 track records with that car too) so they work just fine!

chris101

iTrader: (7)

This is false information.

After 2 years of using 225 45 15s on 15x7s, we opted to finally buy a pair of 15x8s and mount up the 225 45 15s on them (hoosier r6 rcompound tires). The Visible and measured difference of 'contact patch' was between 1/4th and 1/2 inch (closer to 1/2 inch) BUT there was no difference in feel driving on one or the other AND in our case, we did not see better lap times with the 15x8s vs. the 15x7s using the same exact tires. NOTE, however, that in our case the 15x8s wheels were 2 pounds heavier than the 15x7s so that may have helped account for the same lap times for both. (same day, same track, same driver)

hingstonwm

iTrader: (2)

not to mention how stiff the sidewalls are on hoosier r6's

boileralum

iTrader: (8)

x2. Although not optimal, they worked well enough for me to win my class in a divisional autocross championship(Great Lakes Solo Series) on my 00 Civic Si.

chris101

iTrader: (7)

and our car currently holds 6 Time Trial records with NASA using the 225 45 15s on 15x7 wheels FWIW (and got podium every event even if not getting the record!)