Min weight help
 

84 Cutlass Brougham 305 150/232....using Dwights tool and my own math I'm having trouble determing min
weight in L/SA..is the factor 13.4 or 13.5 ? Min weight 3280 or 3288 or 3302...thanks?

Re: Min weight help
 

13.5 x 232 =3132 + 170 = 3302 round down to 3300.

Re: Min weight help
 

On Dwights tool,above the classes the car can run in,it says power/weight factor: 13.44 what is this used for?

Re: Min weight help
 

Shipping weight / NHRA hp = natural class

Re: Min weight help
 

That is the natural classification power to weight factor you get when you divide the shipping weight by the NHRA power factor. That's what Larry was telling you. (Shipping weight is 3117, power factor is 232.) That number fits between 13.00 and 13.49 on NHRA's classification scale so it is a "natural" K car. Rules state that you can remove weight to the lightest possible weight for that class, so the minimum racing weight for K will be 13.00 x 232 = 3016 lbs + 170 driver allowance = 3186 lbs.

Rules also state that you can move one class down or one class up, so the other calculations from the tool show the minimum racing weights for J and L, calculated be multiplying the minimum power to weight factors for each of those classes by the power factor for the engine.

The 13.44 factor determines the classification to start the calculations. It is the numbers found on the spreadsheets that NHRA uses for that car-engine combination and is the starting point their people use to do their calculations. My tools does all that for you.

Re: Min weight help
 

And just another "Thank You" for doing all of the work in getting this site up! It's much (much) easier than the NHRA site. All of the work is done.

Re: Min weight help
 

Thanks Dwight and everyone else for clarifying. We are over the min now just want to make sure I don't do something stupid

Re: Min weight help
 

and I would suggest rounding up to 3305 + 10 and not rounding down which would make you light at the scales

Re: Min weight help
 

Questions regarding running at minimum weight (13.00) with a 13.44 car and about moving a class up or down. Specifically, if a car comes in above minimum weight (ie. 13.44) for a class (K), is it allowed to run on the minimum (13.00) K weight or does it have to run at the actual weight (13.44) in K?


Similar questions if the Oldsmobile were to move to J, would it be allowed to run at 12.50 (minimum J weight) even though the car comes in at 13.44?


Rules state that you can remove weight to the lightest possible weight for that class, so the minimum racing weight for K will be 13.00 x 232 = 3016 lbs + 170 driver allowance = 3186 lbs.

Rules also state that you can move one class down or one class up, so the other calculations from the tool show the minimum racing weights for J and L, calculated be multiplying the minimum power to weight factors for each of those classes by the power factor for the engine.


Can someone provide the page in the rulebook or a copy of the actual rules being referenced?


Thank you in advance for clarification and to Dwight for creating a database.

Re: Min weight help
 

2017 NHRA Rule Book....Section 10A Page 8

WEIGHT
All cars will be permitted to run on the class minimum weight, but
may be no heavier than the minimum for the next heavier class.
Car can move up (lighter) one class or down (heavier) one class. If
weight is added, must be properly attached; see BALLAST. Class

Re: Min weight help
 

Can you guys explain How the plus or minus 250lbs works for GT classification?

Re: Min weight help
 

Basically the same logic as has been explained for moving up and down classes for Stock eliminator, except that you are allowed 250 lbs variance from the car's shipping weight regardless whether you move one or more classes. The limitation is that you may not always be able to be at minimum race weight in a class because of the 250 lb. limit. You may be able to move two classes down at minus 250 lbs, but the 250 lb is the maximum you can remove so you could be carrying extra weight.

Here is an example:
1987 Camaro Coupe with 1970 350-360 w/power factor of 325. Shipping weight is 2930 lb.

2930 / 325 = 9.02 Natural class is GT/G
The combination can fit GT/E at -250 lb, but the minimum racing weight would be 2930 - 250 = 2680 + 170 driver = 2850. The actual calculated lightest weight for a car with that engine in GT/E would be 325 X 8.00 = 2600 + 170 driver = 2770. So that combination in GT/E would have to race at 80 lb heavy for the class. This only is ever an issue in GT classes when moving to lighter classes, but the 250 lb limit prevails.

Re: Min weight help
 

Dwight, that was an excellent explanation!

Now, could you explain all of the nuances of Comp Eliminator in easy to understand language?

Thanks, Al Corda

Re: Min weight help
 

I have to say, Dwight's site is one of the best I ever visited...not only can you get the info you need real quick and easy, you can play around with other combo's in your class to see what you are racing against.

the time that was put into that to get it all together must have been amazing.

Thank You!

Re: Min weight help
 

Comp Eliminator is easy. Open life savings account, empty it, wonder what happened because you never saw it go away.

Re: Min weight help
 

And you know what they say about being a million and running Comp, start with two! Lol