nasaforums.com

Official Forums of the National Auto Sport Association
It is currently Tue Sep 18, 2018 9:03 pm

All times are UTC - 8 hours




Post new topic Reply to topic  [ 5 posts ] 
Author Message
PostPosted: Fri Dec 09, 2016 3:38 pm 
Offline
Forum Time Trialer
Forum Time Trialer

Joined: Sat Feb 11, 2012 10:22 pm
Posts: 227
Location: redwood city, california
Looking at the rules of the nasa proracing site, it would almost look like the calculations are backwards!
Can someone take a look?
Thanks


Top
 Profile  
 
PostPosted: Mon Dec 12, 2016 8:23 pm 
Offline
Forum Hot Lapper
Forum Hot Lapper
User avatar

Joined: Sun Apr 05, 2009 6:42 pm
Posts: 85
Location: Charlottesville, VA
esr wrote:
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 -.

_________________
2006 Honda S2000 TTC #555
2007 Porsche GT3


Top
 Profile  
 
PostPosted: Mon Dec 12, 2016 8:55 pm 
Offline
Forum Time Trialer
Forum Time Trialer

Joined: Sat Feb 11, 2012 10:22 pm
Posts: 227
Location: redwood city, california
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



Snowmants wrote:
esr wrote:
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 -.


Top
 Profile  
 
PostPosted: Tue Dec 13, 2016 4:49 am 
Offline
Forum Hot Lapper
Forum Hot Lapper

Joined: Wed Aug 01, 2007 7:40 am
Posts: 89
Location: Mount Prospect, IL
esr wrote:
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.

_________________
Mike Weber
NASA Great Lakes TT Series Leader


Top
 Profile  
 
PostPosted: Tue Dec 13, 2016 12:34 pm 
Offline
Forum Spectator
Forum Spectator

Joined: Fri Jun 29, 2012 10:02 am
Posts: 17
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.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC - 8 hours


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group