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Tom keedle 03-07-2011 06:43 AM

weight /class questions
 
still can't quite get my head wrapped around this.

1st question is if the car weighs (round numbers,ok?) 2800 lbs and the eng is factored at 200

does that put it at M/S (14.0-14.49) or with driver +170 N/S( 14.5-14.99) at 2970 lbs?

2nd is if i weigh 220, can i subtract 50 lbs weight from the car making it 2750?

X-TECH MAN 03-07-2011 07:30 AM

Re: weight /class questions
 
Quote:

Originally Posted by Tom keedle (Post 244294)
still can't quite get my head wrapped around this.

1st question is if the car weighs (round numbers,ok?) 2800 lbs and the eng is factored at 200

does that put it at M/S (14.0-14.49) or with driver +170 N/S( 14.5-14.99) at 2970 lbs?

2nd is if i weigh 220, can i subtract 50 lbs weight from the car making it 2750?

Figure your class FIRST by dividing the shipping wt. Then add or subtract for the min of the one up or on down class you might want to run other than the natural class. THEN finally add the 170 lbs for the driver wt. and round off the final figure. What ever you weight over the 170 can come out of the car. This is so all drivers wont have an advantage or disadvantage by being to heavy or skinny.

Tom keedle 03-07-2011 07:34 AM

Re: weight /class questions
 
Quote:

Originally Posted by X-TECH MAN (Post 244297)
Figure your class FIRST by dividing the shipping wt. Then add or subtract for the min of the one up or on down class you might want to run other than the natural class. THEN finally add the 170 lbs for the driver wt. and round off the final figure. What ever you weight over the 170 can come out of the car. This is so all drivers wont have an advantage or disadvantage by being to heavy or skinny.

using my 2800 lbs w/o driver put's it in M,correct?
or does car and driver put it in N?

Jim Cassels 03-07-2011 07:39 AM

Re: weight /class questions
 
I'll try to answer your questions.
1st. It would be an M stocker, min wt. 2970 lbs. with driver.
2nd You could take 50 lbs. out of the car, they don't penalize us rotund drivers.
Jim

Jim Cassels 03-07-2011 07:45 AM

Re: weight /class questions
 
Quote:

Originally Posted by X-TECH MAN (Post 244297)
Figure your class FIRST by dividing the shipping wt. Then add or subtract for the min of the one up or on down class you might want to run other than the natural class. THEN finally add the 170 lbs for the driver wt. and round off the final figure. What ever you weight over the 170 can come out of the car. This is so all drivers wont have an advantage or disadvantage by being to heavy or skinny.

Terry, you must be fast, before I could peck out answer you had posted & received a reply.

Rory McNeil 03-07-2011 12:20 PM

Re: weight /class questions
 
Tom, also keep in mind that you don`t neccasarily go by the weight listed on your cars registration papers, or owners manual, sales brochure etc, you have to use the weight per horsepower factor as listed in the NHRA "Stock car classification guide". There will be various factors based on different trim levels, body styles, and engines. For example, say that the model you are trying to determine has a factor of 14.38 lbs per HP, which would give a shipping weight of 2876 lbs. You can either "round it off" to the "top" of M/S, which is 14.00 lbs per HP, for a min weight of 2800 lbs, or round it off to the top of "N",(14.50) which would give a min. weight of 2900 lbs. After that, you add the 170 lbs for the drivers weight. So now the minimum for "M" is 2970, and for "N" it`s 3070. Those are the min. weights that you need to be at the scales after a run. Years ago, you were not permitted to round off the class factors, so my example of a 14.38 factor would have meant that the car & driver combo had to weigh 2876+170 for a min weight of 3046lbs. That is the reason that there were so many oddball combinations, as a 4 door sedan may have fit the class better than a 2 door, or a wagon fit better than a convertible.

Jim Wahl 03-07-2011 12:25 PM

Re: weight /class questions
 
Quote:

Originally Posted by Rory McNeil (Post 244347)
Tom, also keep in mind that you don`t neccasarily go by the weight listed on your cars registration papers, or owners manual, sales brochure etc, you have to use the weight per horsepower factor as listed in the NHRA "Stock car classification guide". There will be various factors based on different trim levels, body styles, and engines. For example, say that the model you are trying to determine has a factor of 14.38 lbs per HP, which would give a shipping weight of 2876 lbs. You can either "round it off" to the "top" of M/S, which is 14.00 lbs per HP, for a min weight of 2800 lbs, or round it off to the top of "N",(14.50) which would give a min. weight of 2900 lbs. After that, you add the 170 lbs for the drivers weight. So now the minimum for "M" is 2970, and for "N" it`s 3070. Those are the min. weights that you need to be at the scales after a run. Years ago, you were not permitted to round off the class factors, so my example of a 14.38 factor would have meant that the car & driver combo had to weigh 2876+170 for a min weight of 3046lbs. That is the reason that there were so many oddball combinations, as a 4 door sedan may have fit the class better than a 2 door, or a wagon fit better than a convertible.

This is a good and simple answer to the question! Very good examples and to the point. This should be posted every time someone asks this question. Nice job Rory! Jim

Jeff Lee 03-07-2011 06:24 PM

Re: weight /class questions
 
When I first started class racing I was confused when I heard "top" or "bottom" of class. Finally I realized it is alphabetical on a vertical chart instead of a horizontal chart. "A" is on the top and "Z" is on the bottom of the chart.

Although you may not even need the NHRA shipping weight, if you want it NHRA almost has it hidden from view in the class guides posted by NHRA. You have to scroll all the way to the right away from black text over white background to the area that is black text over a grey background.

Tom keedle 03-07-2011 09:14 PM

Re: weight /class questions
 
guys, i've got the weight stuff from nhra figured out as far as classification, i just wasn't sure about how the drivers weight figured into it (i ALSO thought it might help some other new guy out,too)


well, at least i don't have to quit eating;)


thanks for the help,guys!


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