225/50/15 on a NA6

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Magpie
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225/50/15 on a NA6

Postby Magpie » Fri Apr 08, 2016 8:50 am

Does anybody run 225/50/15 on a 6.5" rims? Considering going to this size, however not sure of clearance issues.

This is with a 205/50/15 sans bumpstop/springs and jacked all the way up, albeit the camber was at about 2.5° in this photo and it is now 4.0°.
ImageClearance by Eipeip, on Flickr

Does anybody in Brisbane have the 225/50/15 setup so I could do a test fit?

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plohl
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Re: 225/50/15 on a NA6

Postby plohl » Fri Apr 08, 2016 9:44 am

I have a set on 15x8s you can test fit

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plohl
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Re: 225/50/15 on a NA6

Postby plohl » Fri Apr 08, 2016 9:48 am

And no one runs them on such narrow rims...

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Re: 225/50/15 on a NA6

Postby Magpie » Fri Apr 08, 2016 9:51 am

Thought so, look like a rim change would be needed as most of mine are 6.5/7" ones.

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Re: 225/50/15 on a NA6

Postby zossy1 » Fri Apr 08, 2016 9:56 am

You need (as an absolute minimum) 8's to make 225s work... But even with 8's I'd be leaning towards a 205 on a race car to prevent wallowing of the sidewall. 225s shine on 9's.

Magpie
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Re: 225/50/15 on a NA6

Postby Magpie » Fri Apr 08, 2016 10:00 am

Feedback appreciated, sticking with the 205's for 2016. I suspect that guards will need to be rolled for 9" Zossy1.

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Re: 225/50/15 on a NA6

Postby manga_blue » Fri Apr 08, 2016 2:05 pm

I run 225/50r15s on ET35 7" rims on the back of mine. I run 205s on the front because 225 won't fit. That's the setup that holds the NSW club modified class lap records at Wakefield and Eastern Ck GP. So even if its not politically correct on this forum at least it's reasonably quick.

BTW I also sometimes run 205s on 6.5" rims. They're just as quick for me on 6.5 as they are on 7. Don't let the wide rim merchants snow you.
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plohl
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Re: 225/50/15 on a NA6

Postby plohl » Fri Apr 08, 2016 2:13 pm

You need more stance in your life manga :D

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Re: 225/50/15 on a NA6

Postby rascal » Fri Apr 08, 2016 3:02 pm

manga_blue wrote:I run 225/50r15s on ET35 7" rims on the back of mine. I run 205s on the front because 225 won't fit.

Recent pic of manga_blues's car.... :lol:

Image

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pepejesus
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Re: 225/50/15 on a NA6

Postby pepejesus » Fri Apr 08, 2016 7:12 pm

Is there any particular reason you're running 6.5" rims?

A 9" rim is just going to do everything better with that size tyre, why not run it? Even an 8" rim would be better in every way than a 6.5" with a 225 or even 205 tyre.
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pepejesus
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Re: 225/50/15 on a NA6

Postby pepejesus » Fri Apr 08, 2016 7:18 pm

manga_blue wrote:I run 225/50r15s on ET35 7" rims on the back of mine. I run 205s on the front because 225 won't fit. That's the setup that holds the NSW club modified class lap records at Wakefield and Eastern Ck GP. So even if its not politically correct on this forum at least it's reasonably quick.

BTW I also sometimes run 205s on 6.5" rims. They're just as quick for me on 6.5 as they are on 7. Don't let the wide rim merchants snow you.

It's not like the tyres stop working altogether on a narrower rim, it's just not optimal. You would run quicker times on 8s (or even quicker times on 9s) than 7s with a 225. Doesn't mean you can't still run quick times on the 7s.
2004 SE - stock ECU, stock engine, BEGi intake, FMIC, BC Racing 10/6, 15x8s, 225/45 NT-01s
Barbagallo long: 70.488
Barbagallo short: 58.999

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Re: 225/50/15 on a NA6

Postby manga_blue » Fri Apr 08, 2016 7:37 pm

CAMS Supersprint regs limit you to 1" increase in wheel diameter and rim width. 15x7 is the largest you may run on an NA8, 15x6.5 on an NA6.

In terms of laptimes there's really buggar all difference between 195, 205 and 225 on a modified class car. I'm dríven more by price than anything else.
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Magpie
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Re: 225/50/15 on a NA6

Postby Magpie » Fri Apr 08, 2016 8:51 pm

Emailed Yokohama and asking the question on rim/tyre size.

Manga_blue thanks I did not think of CAMS rules for that fact any other ones :(

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MattR
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Re: 225/50/15 on a NA6

Postby MattR » Fri Apr 08, 2016 9:11 pm

Mark your car doesn't run in any CAMS classes per say so would not worry about the wheel widths.

If you jump on Yokohama's motorsport website, and the same for all manufacturers, they generally have very good data sheeys for their competition spec tyres that will give you overall rolling diameter, actual width of tyre as fitted to the test rim, specified as well, nominal rim fitment and maximum and minimun rim widths.

A 225 should be fine on a 7 inch rim through to around a 9 or 10 inch rim, depending on manufacturer.

Again, stop overthinking things, KISS works really well for race cars........

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Re: 225/50/15 on a NA6

Postby The American » Sat Apr 09, 2016 8:32 am

The recommended rim size for a050 in 225/50 is 8" with a range of 6" to 8" (was expecting 9" at least)

The only 245/40 proper r compound available in Aust (for 9"s) is made by AvOn, and is painfully expensive.


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