Super Stock Weight Breaks
 

Could someone possibly give me the weight breaks for GT/AA through GT/GA automatic? I would really appreciate the help. Thanks and Happy Holidays!

Re: Super Stock Weight Breaks
 

GT/AA 8.00-8.49
GT/BA 8.50-8.99
GT/CA 9.00-9.49
GT/DA 9.50-9.99
GT/EA 10.00-10.49
GT/FA 10.50-10.99
GT/GA 11.00-11.49
GT/HA 11.50-11.99
GT/IA 12.00-12.49
GT/JA12.50-12.99
GT/KA 13.00-13.49
GT/LA 13.50-13.99
GT/MA 14.00 or more


B.D.

Re: Super Stock Weight Breaks
 

Thanks for the info Buff Daddy, it is much apreciated!

Re: Super Stock Weight Breaks
 

Here is a handy excel spreadsheet I made for figuring out which GT classes a particular chassis/engine combination can run. It calculates the minimum race weight for each class and shows the ET's for the class index, 0.8 under, 1.0 under and 1.2 under. It also does an estimation of the HP needed to achieve the ETs at the min race weight. You only need to enter the body style shipping weight and the NHRA factored HP for the engine you want to use, and if it is a stick or automatic. It will do all the calculations in any easy to read and print format.

Enjoy.

http://www.employees.org/~bhracing/g...ulator_1p1.xls

Re: Super Stock Weight Breaks
 

Bill that is slick! Is there anyway to download or copy the spread sheet? thanks, Don Jackson

Re: Super Stock Weight Breaks
 

Hey Don,
You need to have Microsoft Excel in order to use the spreadsheet and put in your own data. You can download the spreadsheet from the link in my original e-mail. If you click on the link it should ask you if you want to "open" or "save" the file. Alternately, you can "right click" on the link and select "Save target as" and put it on your local drive. If you save it and have Excel you can do anything you want to it. There is no protection implemented. If you don't have Excel, but you are able to see the spreadsheet, then you probably have the free Excel reader that lets you look at a spreadsheet and print it, but you cannot change any of the data.

Bill

Re: Super Stock Weight Breaks
 

Another question guys; How do I classify my car? I have a 1971 Ford Mustang, I am claiming it as a 2dr Fastback which is a lighter weight. If I choose to run the car in a traditional SS class the shipping weight for an 71 with the 280/305 engine at 10.65. When you do the math the car and driver shipping weight comes to 3418 lbs. If I claim the car as an 72 with 275/313 engine at 10.68 lbs the driver shipping weight comes to 3512 lbs. My question is If I want to run the car in SS/IA the weight break is 10.00-11.00 lbs. To run the car in this class what must the car weigh? Do I subtract 150 lbs from the shipping weight and this is the weight of the car or can I run the car at the bottom of the SS/IA weight break because the natural weight falls between the 10.00 to 11.00 weight? If someone has an clear answer on this please speak up, I called Glendora and of course they are on Holiday break so I couldn't get an answer there today.

Thanks guys!

Re: Super Stock Weight Breaks
 

Bill,

This calculator really works great, I think it answered some of my questions. Do you know if there is one for traditional classes, I am in deseprate need of some answers.

Smitty

Re: Super Stock Weight Breaks
 

Terrance,

For SS/IA at 10.00 lbs. with the 280/305, simply multiply the NHRA factored HP x 10 = 3050 lbs. Add driver weight of 170, for a toal of 3220 lbs. minimum weight. I doubt you can get that car that light, so I'd suggest you run it in SS/JA at 11.00 lbs., or 3525 with driver.

With the 275/313 combo in SS/IA, it would weight 313 x 10 = 3130 + 170 lbs for driver ='s 3300 lbs. That might be achievable, but it'd be pretty light on the rear.

Hope this helps.

Jerry

Re: Super Stock Weight Breaks
 

Jerry,
Thanks for the tip. Beleive it or not the car weighs 3020 lbs without me in it and the only thing that is not in it right now is the second seat. The car ran as a SS/I stick car back in 80's. So I guess what you're saying is that in traditional SS there is no weight amount that you have to play with like you have the 250lbs in GT.

Terrance

Re: Super Stock Weight Breaks
 

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

Re: Super Stock Weight Breaks
 

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.

Re: Super Stock Weight Breaks
 

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

Re: Super Stock Weight Breaks
 

Jerry,

Check your private messages.

Terrance

Re: Super Stock Weight Breaks
 

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.

Re: Super Stock Weight Breaks
 

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

Re: Super Stock Weight Breaks
 

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

Re: Super Stock Weight Breaks
 

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.

Re: Super Stock Weight Breaks
 

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:

http://www.employees.org/~bhracing/coronet440sixpak.jpg

Re: Super Stock Weight Breaks
 

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

Re: Super Stock Weight Breaks
 

Great spread sheet Bill, Thanks!

Can anybody tell me why NHRA does'nt allow wagons in GT? Have they ever allowed them since the GT class inception? And, I see only a select number of Chrysler small and big blocks have a GT rating in the classification guide..does that mean they are the only Chrysler engines allowed to run GT?

Thanks, Gordie

Re: Super Stock Weight Breaks
 

Bill I got it down loaded, thanks a bunch. Don Jackson

Re: Super Stock Weight Breaks
 

Ahhhh...got it! Now can somebody explain why GT/LA has a 11.85 index and GT/L has a 11.60 index?
And looking at the chart with a 3126 shipping weight and a 1969 390/340/407 doesn't fit in in any GT class?

Thanks, that's a really useful tool!

Re: Super Stock Weight Breaks
 

Jeff and Brian, you both have a situation that wasn't handled well by the spreadsheet. In both cases the HP/Weight is less than 8.0. GT/A is from 8.0 to 8.49. When the weight break was less than 8.0 the spreadsheet didn't know what to do. I made some changes and there is a new version at:

http://www.employees.org/~bhracing/g...ulator_1p1.xls

This version will flag combinations that have breaks below 8.0 and also shows the calculated weight break.

Thanks for the feedback. You fast guys always break things..!! :)

Re: Super Stock Weight Breaks
 

Bill Harris! I just want to thank you for the effort you put into this, but according to this formula the 440-6Pak would have to make around 800 HPto be somwhat competetive! Theres as much chance of that happening as me looseing 175#! I haven't weighed that since i was born! For SS/CA my car has to weigh 3670 # with driver, that's with a Hemi , that makes about 850 HP. The poeple that i've talked to didn't know how to do the GT thing in reverse, as in late model eng in older body....Thanks a Bunch, John Lang

Re: Super Stock Weight Breaks
 

John the 440 six pack in super stock is 385 hp in stock its at 405 e body 411 b body.

Re: Super Stock Weight Breaks
 

Bill...Again, thanks a lot, great program! Using the '70 AMX @ 3223 shipping weight and the '69 390 cross-ram engine, the program illustrates how not all cars (John Lang also) are not suitable for SS/GT. A SS/B cross-ram legal '69 AMX is 610#'s lighter than the GT/AA equivalent, thus, can never be a player. However, if you drop a '69 AMC 290 into the '70 AMX with an auto transmission for GT/LA, you would have a seriously decent SS/GT car, even against the late-model sheetmetal. At least I think so...and there will always be advantages to using the late-model FWD conversions.
Since I'm a stick-only racer, GT/L is hampered by a .25 harder index over GT/LA.
Guess if I ever want to race with a pair of Holley's on my 390 I have to switch the front-end to a '69 model. Someday.....:(

Everybody needs to add this program to their favorites, especially NHRA!

Re: Super Stock Weight Breaks
 

Hey Gordie, Just because there isn't a specific HP for SS/GT in the classification guide for a particular engine doesn't mean that it can't be used in GT. Those engines that have a GT only HP rating are due to AHFS hits on combinations that use that engine in a GT car. If a GT car uses an engine and goes too fast, the NHRA will give HP to that engine when it is used in a GT car, but doesn't hit the traditional S/S cars that use the same engine. That is shown in the classification guide with a separate GT HP line. If there isn't a GT specific entry, you use the regular S/S rating for the engine.

Re: Super Stock Weight Breaks
 

Bill,

Thanks again for the spreadsheet!! It is much quicker than the way I had done it in the past!

Bryan

Re: Super Stock Weight Breaks
 

Bill,

The GT/MA index is 12.05. You have it the same as GT/LA at 11.85. But thanks, it sure works slick.

Jerry

Re: Super Stock Weight Breaks
 

Oops... fixed that little issue.... new version:

http://www.employees.org/~bhracing/g...ulator_1p1.xls

You guys are good debuggers. Sorry 'bout that!

Bill