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 Post subject: ST4 Tire tutorial
PostPosted: Fri Dec 09, 2016 10:22 pm 
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Can someone give a general classification of the most common tires for ST4

Thanks


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 Post subject: Re: ST4 Tire tutorial
PostPosted: Mon Dec 12, 2016 8:51 pm 
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I am told that te Hoosier r6 or r7 can't remember which one is the way to go(written down at work)
A BFg r1 would be a bit slower but last longer.


uote="esr"]Can someone give a general classification of the most common tires for ST4

Thanks[/quote]


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 Post subject: Re: ST4 Tire tutorial
PostPosted: Tue Dec 13, 2016 12:47 pm 
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Most common tire is going to be a Hoosier R7, possibly an A7 although this will depended heavily on the cars ability to get close to the weight/power ratio.


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 Post subject: Re: ST4 Tire tutorial
PostPosted: Tue Dec 13, 2016 1:45 pm 
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esr wrote:
Can someone give a general classification of the most common tires for ST4

Thanks

I would think that we will see R7, RR, R1, RS, Z214 (C71), RC-1, and TD as the most common, with the Autocross tires for those that are under powered (A7, R1S, RS AC, Z214 (C91).

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 Post subject: Re: ST4 Tire tutorial
PostPosted: Thu Dec 15, 2016 10:38 am 
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Greg, could you confirm something for us all. Under 7.3.1 - 4)Maximum tire size in ST4 is 275mm. Under ST 7.4.2 Modification Factors - Size 275 to 250 (DOT-approved) = +0.3 . So does this mean ALL ST4 cars get that +0.3?

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 Post subject: Re: ST4 Tire tutorial
PostPosted: Thu Dec 15, 2016 1:51 pm 
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flier129 wrote:
Greg, could you confirm something for us all. Under 7.3.1 - 4)Maximum tire size in ST4 is 275mm. Under ST 7.4.2 Modification Factors - Size 275 to 250 (DOT-approved) = +0.3 . So does this mean ALL ST4 cars get that +0.3?

No, it means that all ST4 cars get the +0.3 or the +0.7 for 245mm or smaller tires.

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 Post subject: Re: ST4 Tire tutorial
PostPosted: Fri Dec 16, 2016 3:56 am 
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Greg G. wrote:
flier129 wrote:
Greg, could you confirm something for us all. Under 7.3.1 - 4)Maximum tire size in ST4 is 275mm. Under ST 7.4.2 Modification Factors - Size 275 to 250 (DOT-approved) = +0.3 . So does this mean ALL ST4 cars get that +0.3?

No, it means that all ST4 cars get the +0.3 or the +0.7 for 245mm or smaller tires.


If that's the case, why is the base ratio not 12.3:1? These two tire rules functionally make the ST4 base ration 11.7:1 and pushes us closer to ST3.


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 Post subject: Re: ST4 Tire tutorial
PostPosted: Fri Dec 16, 2016 11:17 am 
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JHo wrote:
Greg G. wrote:
flier129 wrote:
Greg, could you confirm something for us all. Under 7.3.1 - 4)Maximum tire size in ST4 is 275mm. Under ST 7.4.2 Modification Factors - Size 275 to 250 (DOT-approved) = +0.3 . So does this mean ALL ST4 cars get that +0.3?

No, it means that all ST4 cars get the +0.3 or the +0.7 for 245mm or smaller tires.


If that's the case, why is the base ratio not 12.3:1? These two tire rules functionally make the ST4 base ration 11.7:1 and pushes us closer to ST3.

Really? And by your logic then, since many (if not most) ST3 cars are on 275's, then ST3 is functionally 9.7:1. :roll:
It makes it easier to move from one class to the other if the tire size Mod Factors are the same.

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 Post subject: Re: ST4 Tire tutorial
PostPosted: Sat Dec 17, 2016 8:38 am 
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Greg G. wrote:
Really? And by your logic then, since many (if not most) ST3 cars are on 275's, then ST3 is functionally 9.7:1. :roll:
It makes it easier to move from one class to the other if the tire size Mod Factors are the same.


There is a difference between people choosing to run a 275 to get a break on the power to weight and people being forced to run a 275 by rule. I know it's in the minority but there are several people in my region who have expressed an interest in running wider than 275 in ST4 but can't.


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 Post subject: Re: ST4 Tire tutorial
PostPosted: Sat Dec 17, 2016 10:21 am 
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In my opinion the Toyo proxes rr 275 or an even harder tire should put you at 12:1.
Any one wanting to go much faster than this should and can probably afford st3.
It seems to me that at this rate you guys will kill st3.
St4 needs to be a good bit slower than st4
Looks like we have a bunch of st3 rejects wanting to go to st4 and not wanting to start fresh. This is a bad way to create something that will grow.



JHo wrote:
Greg G. wrote:
Really? And by your logic then, since many (if not most) ST3 cars are on 275's, then ST3 is functionally 9.7:1. :roll:
It makes it easier to move from one class to the other if the tire size Mod Factors are the same.


There is a difference between people choosing to run a 275 to get a break on the power to weight and people being forced to run a 275 by rule. I know it's in the minority but there are several people in my region who have expressed an interest in running wider than 275 in ST4 but can't.


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