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esr

class calculator explenation

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esr

Looking at the rules of the nasa proracing site, it would almost look like the calculations are backwards!

Can someone take a look?

Thanks

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Snowmants
Looking at the rules of the nasa proracing site, it would almost look like the calculations are backwards!

Can someone take a look?

Thanks

 

I saw this too. The modification factors appear to be reversed between + and -.

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esr

A director told me it can be interpreted either way but I think it is easier to think of it as backwards from what is written.

Also there is a mistake in the tire section it list the Hoosier a6, a,7 when it should say r6,r7

 

 

 

Looking at the rules of the nasa proracing site, it would almost look like the calculations are backwards!

Can someone take a look?

Thanks

 

I saw this too. The modification factors appear to be reversed between + and -.

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mweber
A director told me it can be interpreted either way but I think it is easier to think of it as backwards from what is written.

Also there is a mistake in the tire section it list the Hoosier a6, a,7 when it should say r6,r7

 

"ST4 Only: DOT-approved R-comp Autocross tires = -1.0 (examples: A6, A7, R1S, RS AC, Z214-C90/91)"

 

This looks correct to me, R6 and R7 are not autocross tires.

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geeveepee

The rules are written assuming that you:

 

First, figure your raw weight to power ratio

Second, apply any mod factors for your setup

Third, compare the result to the class w/p limit.

 

Doing it this way will make the stated +/- of the mod factors look correct.

 

 

Some people find it more intuitive to do it backwards, i.e:

 

First find your class w/p limit

Second, apply any mod factors for your setup

Third, compare the result to your raw w/p ratio

 

Doing it this way you will need to reverse the stated +/- to come out with the correct answer

 

With regard to the tire question, the mod factor for autocross tires is correct for Hoosier A6 / A7. Hoosier R6 / R7 do not need to take this penalty.

 

In running NorCal ST3 over the last two seasons in a 3200 pound 350z, it was clear that the A7's were significantly faster but significantly less durable (at least at 275). If I were running ST4 next year I would definitely be sticking with R7's. But that's just my two cents.

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