15" x 6"

[Beran]

Anyone know a source?
I run an MK3 golf and it seems like Hoosier has more options for me if I move to a 15" rim. But the rules require a 6" wide one. All I can find are 6.5" wide ones.

Any thoughts of 14" versus 15"?
Thanks,
Beran

[StangIT]

Try Diamond Racing Wheels

[RacerBill]

Beran: Let me know if you would like a set of stock Audi rims - 15x6, 4x100.

[shwah]

Corrado G60 wheels.

[ScotMac]

Anyone know a source?
I run an MK3 golf and it seems like Hoosier has more options for me if I move to a 15" rim. But the rules require a 6" wide one. All I can find are 6.5" wide ones.

Any thoughts of 14" versus 15"?
Thanks,
Beran
[/b]

Beran, if you are currently running 205's, and just want to switch to 15's and get the lower profile w/ the same diameter, then it is doable. For example, a hoosier 205/55/14 and a 205/50/15 are both 22.8.

However, if you are running 225 or want to switch to 225's, then 15" rims are problematic. Again using hoosier as the example, if you are currently running 205/55/14 or 225/50/14 (22.8" and 22.9" diam, respectively), and want to switch 225 15's, you have two choices 225/50/15 or 225/45/15. The 225/50/15 is 23.8" in diameter, w/ the obvious increase in ride-height, drag and weight. The 225/45/15 is 22.9" diameter (good), but is only recommended for 7-8.5" rims...which obviously doesn't work for ITB.

I have only researched hoosiers, but i would assume the other manufacturers are supplying similar sizes.

HTHs, -Scot

[Beran]

Good stuff -
I'll have to check out what the audi rims look like. Also any sources for corrado G60 rims?

Yeah - I run the 225/14 Hoosiers now. I was thinking about being able to have options for different tracks rather then changing the final drive gear. I also was looking for a shorter side wall for less deflection and rollover. I am not against trying the 205's on the 15" rims which might be faster at some of the higher speed tracks then using the 225 14" or 15". On some of the slower tracks like Lime Rock and NHIS the fatter tire might be better.
ScotMac - thanks for the diam sizes.
Maybe I can try and squeeze the 225/45/15 onto the 6" rim - Anyone done it?
Thank for all the help!
Beran

[Knestis]

It's not just a function of getting the tire ON the wheel, it's the profile that results. A 45 series tire is going to generally be less forgiving of less-than-optimal wheel width, creating a funky profile that doesn't put the tread on the track as anticipated.

Check with PhilTireService.com and see what he recommends but I'd be surprised to find out that a taller tire makes you faster, unless you are running out of revs in 5th someplace, for more than a little while...

K

[JoshS]

Maybe I can try and squeeze the 225/45/15 onto the 6" rim - Anyone done it?[/b]

Autocrossers do it all the time. Only testing will tell you whether or not it's faster.

[rabbidmk1]

Im running 15X6 SSR competition wheels. They are 8.8# each and have been great this season on my mk3... A little on the spendy side though. $299 each IIRC...

[Beran]

rabbidmk1 - do you use spacers front and rear? What size?
I just ordered a set of SSR rims - will have them Wed.

Josh - yep - and more and more testing... although with the new data acquisition it will make it easier.
I still need to get a video camera setup... too many options! Are you coming east for the holidays? If you do you should call me and we can get together.

Thanks!
Beran

[JoshS]

Josh - yep - and more and more testing... although with the new data acquisition it will make it easier.
I still need to get a video camera setup... too many options! Are you coming east for the holidays? If you do you should call me and we can get together.[/b]

Not sure yet. If I'm coming we'll definitely try to get together. Thanksgiving is more likely than Christmas.

You still need video, I still need to get data acquisition. Too many options, I'm just deadlocked. Most important thing for me is ease of analysis. I don't want to have to spend hours in front of the computer to learn something. I want the lessons to be learned from the data to be quick and obvious.

[jlinfert]

Maybe I can try and squeeze the 225/45/15 onto the 6" rim - Anyone done it?
[/b]

I squeeze 225/45R13 hoosiers on 13x6 wheels. Heck until we found the 6's they were on 5.5's!

[rabbidmk1]

rabbidmk1 - do you use spacers front and rear? What size?
I just ordered a set of SSR rims - will have them Wed.

Thanks!
Beran
[/b]

I have 10mm spacers front and rear with wheel studs and a 205/50/15 kumho tire. I have found that without the spacers, the tires hit my coilovers.


Aaron

[ScotMac]

It's not just a function of getting the tire ON the wheel, it's the profile that results. A 45 series tire is going to generally be less forgiving of less-than-optimal wheel width, creating a funky profile that doesn't put the tread on the track as anticipated.

Check with PhilTireService.com and see what he recommends but I'd be surprised to find out that a taller tire makes you faster, unless you are running out of revs in 5th someplace, for more than a little while...

K
[/b]

It is not taller. But you are right about the sidewalls. It is questionable. I am running the 225/50/14's, and even tho hoosier recommends 6-8" rims, i think the sidewall angles are pretty extreme. The lower profile of the 225/45/15 would make the sidewall angle EVEN MORE extreme. I wouldn't do it.


But, hey, if you got a lot of money, try it, and please let us know if it works!

Oh, and this is one the exact reasons that i proposed that we allow 7" rims in ITC/ITB. How do i go about submitting the rule change letter?

[ScotMac]

Oh, and this is one the exact reasons that i proposed that we allow 7" rims in ITC/ITB. How do i go about submitting the rule change letter?
[/b]

Anybody? The only email address i have found is [email protected] it would seem that is for the CRB, not the ITAC.

Does the letter need to be a particular format? Include my SCCA membership number, i assume. Anything else?

[shwah]

Just send an email to that address.

Dear CRB,

I would like to request this for these reasons.

Here is some more detail, and logic supporting my reasons.

thank you,

My name.


Nothing fancy required, just

[Beran]

I ran a set of 225/50ZR-15 this past weekend at Lime Rock. The reason I went with the taller tire was because I wanted a little more speed since I was running out of RPM in the wrong spot. The tire fit fine on my MK3 with 10mm spacers in front and smaller spacers in rear..maybe 5mm maybe a little bigger. I did not measure them.
The taller tire helped a little bit with th RPM but I think I should have gone with the 225/45ZR-15 with the shorter sidewall. The taller sidewall did not provide as quick a response for turn in and not enough of a crisp clean feedback. They felt a little muted compared to some of the other hoosier combinations I have run.
I think the best combination is going to be the 225/45 and then change the final drive to something else.
I like SSR rims. They are very light weight.
Thats my .02
Beran

[rabbidmk1]

Wow 225 on a 6" rim seems wide. I am running 205/50 15 kumhos on my 15X6 SSR's and they fit a little tight with 10mm spacers on front and 5 mm on the rear (on the mk3). Are the Hoosiers designed to run on a narrower rim then other brand tires?

[Beran]

I have no idea if the hoosiers are designed for narrower rims then the Kumos.
From the hoosier tire sheet:
The 225/50-15 have a tread width of 8.8 and a section width of 9.8 recommended rim size is 6-8"

[Gary L]

I have no idea if the hoosiers are designed for narrower rims then the Kumos.
From the hoosier tire sheet:
The 225/50-15 have a tread width of 8.8 and a section width of 9.8 recommended rim size is 6-8" [/b]

...which is not the same as it was for the Hoosier S04's and S05's. Those older Hoosier 225/50-15's had a recommended rim width of 7-9". I don't have older data for any other sizes, but at least 3 of the 15" R6's now have slightly narrower recommended rim widths than the S04's and S05's did:

205/50-15 was 6.0-8.0" now 5.5-7.5"

225/45-15 was 7.0-9.0" now 7.0-8.5"

225/50-15 was 7.0-9.0" now 6.0-8.0"

The 225/50-15 also appears to be about 2% taller than it was in the older versions.