Heads-Up Runs

[Mike Carr]

Originally Posted by mopar jeff

I am new to this game, so I will ask this probably stupid question anyway. Can someone please explain the adding horsepower thing. How does that hurt you? Does it change your factor number, and you have to carry more weight to slow you down? Also if someone runs far enough under to get slapped with horsepower, does it affect anyone running that combo, or just that particular car? Are you then labeled everywhere you go? Hopefully someone can better explain this to the newbie. Thanks.

Jeff, if you were to have, say, a '64 426 Max Wedge. 415 rated NHRA. If you run -1.40 under (9.900 or quicker in A/SA), a combination gets hit 3.25%, or 14 HP, so you're now at 429. You'd have to carry an extra 112 pounds. All 426/415 Max Wedge racers receive this penalty. And yes, it can change the classification of the vehicle. As an example, when the '93-97 GM F-bodies came out, they were rated at 275 and were in, I believe H/SA in 1995. They are now rated over 340 (I forget the actual number) and can run up to B and C/SA. Hope this helps.

[mopar jeff]

That does make more sense, so it's all about weight. I guess you would have to get creative in how you add that much to the car, since you can only have 100lbs. of ballast. Does 14HP really = 112lbs? That should be about 1/10th of a second too.

[Andrew Hill]

Originally Posted by mopar jeff

That does make more sense, so it's all about weight. I guess you would have to get creative in how you add that much to the car, since you can only have 100lbs. of ballast. Does 14HP really = 112lbs? That should be about 1/10th of a second too.

It depends on the class. A/SA is an 8 lbs per cubic inch class, and 14x8= 112 lbs. AA/SA is 7.5 lbs/in and it goes down in half lb increments for the most part.

[mopar jeff]

Originally Posted by Andrew Hill

It depends on the class. A/SA is an 8 lbs per cubic inch class, and 14x8= 112 lbs. AA/SA is 7.5 lbs/in and it goes down in half lb increments for the most part.

Is there someplace you can see this information broken down by class?

[Andrew Hill]

Originally Posted by mopar jeff

Is there someplace you can see this information broken down by class?

The rule book has the weight break for each class, and NHRA's website has links to excel files that show the horsepower factors for each combination.

Here is the link:
http://www.nhra.com/competition/classification.aspx

[mopar jeff]

Originally Posted by Andrew Hill

The rule book has the weight break for each class, and NHRA's website has links to excel files that show the horsepower factors for each combination.

Here is the link:
http://www.nhra.com/competition/classification.aspx

So if my combo has a factor of 15.01, then I would have to add 15.01 pounds for every horsepower they assess?

[Andrew Hill]

Originally Posted by mopar jeff

So if my combo has a factor of 15.01, then I would have to add 15.01 pounds for every horsepower they assess?

No, 15.01 is the factor that determines what class your car falls in. Say the rated horsepower was 250 and the shipping weight was 3753, this would give a factor of 15.01. O/SA is the natural class for car with factors of 15.00-15.99. This means that you could in N/SA, O/SA, or P/SA at their appropriate weight breaks. This car would have to weigh (15x250) + 170= 3920 lbs in O/SA. If the horsepower rating were changed to 255, the factor would be 3753 (shipping weight) divided by 255 (the new horsepower rating) which is 14.72. This would make it a natural N/SA car and it could run M/SA through O/SA at the appropriate weights.

[Mike Carr]

Originally Posted by mopar jeff

So if my combo has a factor of 15.01, then I would have to add 15.01 pounds for every horsepower they assess?

Any car that goes more than -1.40 under the Index, has to add 3.25% to the at-the-time HP rating. Max Wedge 426/415 = 415 x .0325 = 13.4875. All numbers are rounded up, so it's 14 HP, and your car is a now a 426/429.