Super Stock Weight Breaks

[JRyan]

Wow,

I knew we should have bought that car when you had it for sale. That's a lightweight piece for one of those cars. Our BOSS 351 (D/S) weighs 3550 with 1/2 tank of gas (stock tank) and 75 lbs. of ballast with a 200 lb. driver. It was 2005 lbs. on the front, and 1545 lbs. on the rear. Of course it still has the heater in it and hasn't been stripped at all (even though it's been a Stocker since 1977), but that's still 200 lbs. lighter than ours empty. We don't want to mess with ours, as we plan to restore it at some point.

As far as the weight goes, you can either add enough to go a class lower than the natural class (SS/IA in your case), or remove enough to make it one class higher than the natural class. How you attach the ballast is what NHRA is looking at if you go down a class. It looks as though you could easily run SS/IA with the 280/305 combo in your car.

Jerry

[Bill Harris]

You don't have a choice on shipping weight in the regular S/S classes. The NHRA classification guides tell you what the shipping weight is for a particular body style/engine combination, and that's that. You can run the "natural" class, or move up one class, or down one class, by juggling weight. That's it. If the car's natural class is, for example, SS/E, then you can run it in SS/D, SS/E or SS/F. Even if you could take out enough weight to get it into the SS/C territory, it wouldn't be legal.

So, on a '71 Mustang Fastback with a 351/280/305 shipping weight is 3249 lbs directly from the classification guide. That's a HP/weight of 10.65 (3249/305 = 10.65). That puts it in SS/I which is 10.00 to 10.99 lbs/hp. If the car was a Mach I the shipping weight for the 351/280/305 engine is 3296 straight from the classification guide. That is HP/weight of 10.84 (3296/305 = 10.84) which puts it in..... you guessed it.... SS/I. So it doesn't matter if you claim the car as a fastback or a Mach I, you'r still a natural SS/I.

So now you can run SS/I, or go up one class and run SS/J, or down one class and run SS/H. That's it.

At this point, the shipping weight of the car is totally irrelevant. All you need to know is that the shipping weight ALLOWS you to run SS/H, SS/I or SS/J. Now you can calculate the minimum weight for the car in each class. The shipping weight doesn't come into play anymore. The only thing that is important now is the factored HP and the class. For SS/H, the minimum HP/weight is 9.50. So at an NHRA factored HP of 305, the car has to weigh 9.50 x 305 = 2897.5 lbs..... but that's not all.... You ALWAYS have to add 170 lbs for the driver, so the race weight for SS/H will be 2897.5 + 170 = 3067.5 lbs. Using the same procedure, the minimum race weights (with you in the car) are:

SS/H: (9.50 x 305) + 170 = 3067.5 lbs
SS/I : (10.00 x 305) + 170 = 3220 lbs
SS/J: (11.00 x 305) + 170 = 3525 lbs

Those are the minimum weights that you have to weigh when you cross the scales after a run with you in the car. You can be heavier of course. However, you may get an argument from tech if you are claiming SS/H and you go across the scales at 3300 lbs (which is SS/I territory). They might not say anything.. and they might give you ****... hard to tell.

Now, just because a car is ALLOWED to run a particular class doesn't mean that it CAN. If you want to run at the bottom (lightest) of SS/H with the '71 you have to get the car down to 3068 lbs with you in it in a manner that is legal for S/S. Good luck with that.

Stock classes and weights are calculated exactly the same way but using the stock HP factors.

My '71 Mach I with a 429/375/360 runs D/SA at a minimum race weight of 3590 lbs.... (9.50 x 360) +170 = 3590. I could run C/SA at (9.0 x 360) + 170 = 3410 lbs, but it would be really hard to get 180 lbs out of my car legally. Anyway, it wouldn't hook if I could.

Hope that helps.

Bill and Jerry thanks for your assitance in this matter. Reading that rule can get confusing when it's something you are not used to. When I look at I read and interpit one thing and someone else see's it another way, that why I was calling California for clarification . I knew however that someone on here could explain it.
Bill, is your car a Ram Air car? I see they just took HP off a the 70 and 71 370hp 429. If I had and abundance of big block parts I might would try to run that combo but that would be a beast of a car. Thanks again guys for all your help, hopefully I will see you guys down here in Florida at one of these Divisionals, if it's anything I can do for you just let me know.

Terrance

Originally Posted by JRyan

Wow,

I knew we should have bought that car when you had it for sale. That's a lightweight piece for one of those cars. Our BOSS 351 (D/S) weighs 3550 with 1/2 tank of gas (stock tank) and 75 lbs. of ballast with a 200 lb. driver. It was 2005 lbs. on the front, and 1545 lbs. on the rear. Of course it still has the heater in it and hasn't been stripped at all (even though it's been a Stocker since 1977), but that's still 200 lbs. lighter than ours empty. We don't want to mess with ours, as we plan to restore it at some point.

As far as the weight goes, you can either add enough to go a class lower than the natural class (SS/IA in your case), or remove enough to make it one class higher than the natural class. How you attach the ballast is what NHRA is looking at if you go down a class. It looks as though you could easily run SS/IA with the 280/305 combo in your car.

Jerry

Jerry,

Check your private messages.

Terrance

[Bill Harris]

Terrance,

My car is a SCJ which is the 375 HP with ram air combination. It uses the Holley 780 and solid lifter cam. The 370 HP combo is the Q-Jet with a hydraulic cam. NHRA took HP off the SCJ combo a few years ago and it is now factored at 360 for stock and 371 for S/S. This latest NHRA adjustment for S/S only applied to the CJ which was still at 380 for S/S. Now the SCJ and CJ are both at 360 for Stock and 371 for S/S. In S/S the difference between the two engines boils down to the carburator. I don't know why anyone would run a Q-jet when a 780 Holley could be used without any penality.

The HP penality for having ram-air was taken off a while ago so now ram-air and non-ram-air all have the same factored HP.

I have given serious consideration to doing a '71 429SCJ Mustang in S/S, but have pretty much given up the idea. I couldn't use my car since it is an original J code SCJ/4-speed/Drag-Pack car and I would be crazy to tub it. The NHRA isn't going to take any more HP off the S/S factor until someone runs the combination, and at 371 I think it is too high to be compe***ive in class. Since no one has been running the engine in S/S there is a ton of development work that needs to be done on the heads and I don't want to be the guinea pig. I know there is one person working on the engine for use in SS/GT. It will be interesting to see how it comes out when he gets it on the track. If there was an aluminum head approved for it, like the Edelbrock or the original A-429 Ford Motorsport head, it would be a LOT more attractive.

I'll be in Bradenton and Gainesville in February. Stop by if you are at the track.

Originally Posted by Bill Harris

Terrance,

My car is a SCJ which is the 375 HP with ram air combination. It uses the Holley 780 and solid lifter cam. The 370 HP combo is the Q-Jet with a hydraulic cam. NHRA took HP off the SCJ combo a few years ago and it is now factored at 360 for stock and 371 for S/S. This latest NHRA adjustment for S/S only applied to the CJ which was still at 380 for S/S. Now the SCJ and CJ are both at 360 for Stock and 371 for S/S. In S/S the difference between the two engines boils down to the carburator. I don't know why anyone would run a Q-jet when a 780 Holley could be used without any penality.

The HP penality for having ram-air was taken off a while ago so now ram-air and non-ram-air all have the same factored HP.

I have given serious consideration to doing a '71 429SCJ Mustang in S/S, but have pretty much given up the idea. I couldn't use my car since it is an original J code SCJ/4-speed/Drag-Pack car and I would be crazy to tub it. The NHRA isn't going to take any more HP off the S/S factor until someone runs the combination, and at 371 I think it is too high to be compe***ive in class. Since no one has been running the engine in S/S there is a ton of development work that needs to be done on the heads and I don't want to be the guinea pig. I know there is one person working on the engine for use in SS/GT. It will be interesting to see how it comes out when he gets it on the track. If there was an aluminum head approved for it, like the Edelbrock or the original A-429 Ford Motorsport head, it would be a LOT more attractive.

I'll be in Bradenton and Gainesville in February. Stop by if you are at the track.

I will be sure to do that, I would really like to have my engine ready by Bradenton but I don't think I will have it. My car is an original 4 speed Mach 1 car, it came off the assembly line in New Jersey in late 1970. Some where along the way it was converted to a ram air car which I am told those parts are very hard to come buy. I can definently agree w***h you not wanting to tub it especially being a 429 drag pack car. Looking forward to seeing you down this way in a few months.

Terrance

[John Lang]

You gentelmen have helped a bunch of people with there S/S cars, Maybe you can help me ? I've got a SS/CA 65 Dodge Coronet which is a 7.00 # X 500hp= 3500# + 170 = 3670 for SS/CA. Well my question that i've asked other racers, is to go to SS/GT, using a 70 Cuda 440-6Pak in my 65 Coronet. The 440 is rated at 390 factory, and 405 NHRA in SS. I just can't afford the Hemi.The 440 would cost about 1/3 the price of the Hemi! What G/T class would my tank fit in ? Thanks in advance John Lang # 365 SS/CA

[Jeff Lee]

Originally Posted by John Lang

You gentelmen have helped a bunch of people with there S/S cars, Maybe you can help me ? I've got a SS/CA 65 Dodge Coronet which is a 7.00 # X 500hp= 3500# + 170 = 3670 for SS/CA. Well my question that i've asked other racers, is to go to SS/GT, using a 70 Cuda 440-6Pak in my 65 Coronet. The 440 is rated at 390 factory, and 405 NHRA in SS. I just can't afford the Hemi.The 440 would cost about 1/3 the price of the Hemi! What G/T class would my tank fit in ? Thanks in advance John Lang # 365 SS/CA

To further the question, do you calculate the shipping weight of the car at the original HP or the updated/refined HP to calculate for a GT class? My 1970 AMX with a 390/325/315 falls at 9.92 or 11.15 with a 360/290/280 (only two engines available in 1970). NHRA doesn't list car's by shipping weight. Do you take 9.92 x 325 or 315 and no allowance for driver weight? Or do you use 11.15?
I'm assuming John Lang will need the formula for his 1965 Coonet also.

[Bill Harris]

Ahhh... but NHRA does indeed list shipping weights in the classification guides. When you open the guide the page you are looking at has a white background and gives FACTORED HP to shipping weight calculations. If you pan to the right, the table is repeated for each engine/body style but this time listing the shipping weights and the background is grey. So for the '70 AMX the shipping weight is 3123 for the 360/290/280 and 3126 for the 390/325/315. You can calculate backwards from there and get the weight break listed in the left side table. The numbers in the HP/weight table are always done using the factored HP.

The rules for the GT classes is that for a body style that has multiple engines, you are supposed to use the shipping weight for the car "with the heaviest gasoline engine and appropriate transmission". So for John's Coronet, assuming it is a 2 door sedan, the heaviest engine, and therefore the heaviest shipping weight, is 3550 lbs. If you plug that shipping weight and the 405 HP for the 440 SixPak into my spreadsheet it looks like this:

[Bryan Broaddus]

Bill,

Your spread sheet is a great tool. It can't seem to get it to work above 420 HP though. I was just playing around with it for our GT/AA combination with a 425 HP 454 rated at 430/435. I am not being critical just thought I would let you know, although you probably know this since you wrote it!

Thanks for posting it for us to use!

Bryan