Car classification ?

[Stewart Way]

Yes we did Will. As for the cage you only need to meet the safety requirements for the class you run. You will need a 8.50-9.99 cage in GT/A thru GT/G. 25.4 or 5 cage is only needed if you run 8.49 or quicker.

Yea, I saw the Dart at Vegas I think it was. Saw the front fenders had side lights but thought they still could have been glass. Guess not. As for it not making sense ( NHRA rules don't always "make sense") to have the glass fenders and have to add weight somewhere else, I thought thats why most people put lightweight componants on the front of a car, so the could "add the weight back in somewhere else". Thats why they are on my car, plus I was told they had to be.

[Ryck Campbell]

Gentlemen,

SS/GT is a little different than SS in that there is no "natural" class for a GT car. You take the heaviest model of your choosing (in this case the heaviest GTS is the 440 @ 3229; there was no Hemi in a 1969 Dart according to the class guide).

You divide the shipping weight of the car chosen and divide that number by the horsepower of your engine. In this case it's the 1970 383 - 330/335 rerated to 304 with OEM heads. That number is 9.80. Since GT/DA is a 9.50 weight break, you would be running at a .30 per horsepower disadvantage in GT/DA @ 3145 instead of at the top of the class at 3055. This car can also run GT/EA @ 3210, GT/FA @ 3360 or GT/GA @ 3510.

I hope this clarifies the way to calculate SS/GT weights.

[Stewart Way]

Ryck
The car in question is a 68, not a 69.
3 questions.
First, since the rulebook says you can adjust the weight a maximum of 250 lbs can't you remove 90 lbs to get to the 9.5 break? You could also run C at 9.0 or 2906 since it is less than 250 lbs from the natural 9.80 break. Not that you could get the car that light with a 383/440. Also, using your example, how can you run GT/GA at 3510 since that is 285 greater than the 3225 weight at 9.8?
Second question. Since we are talking 68, would you not use the Hemi weight of 3020 because the rule book says "by using the power to weight factor of the vehicle with the heaviest gasoline engine"? The Hemi is the heavieat gasoline engine. The rule book doesn't say use the "heaviest model", it says "vehicle with the heaviest gasoline engine".
Third. Almost hate to ask this one. If question #2 answer is use the Hemi factor for a 68, then would you not have to use the body equipment required on that car? Meaning you need the glass fenders as well as the hood. If the answer to 2 is "heaviest model', how can we add the glass hood (and fenders) since they were never on the 440?
Thanks for weighing in.

[Jeff Lee]

The Hemi is the heavieat gasoline engine. The rule book doesn't say use the "heaviest model", it says "vehicle with the heaviest gasoline engine".

Your verbiage may be off...but if not, then NHRA would have to know the weight of all engines and then you run into the issue of how to weigh them (exhaust manifolds, accessories, etc.). NHRA would need to know the weight of a slant-six and everything in between it and the Hemi.
I believe the accepted method of calculating is you use the heaviest shipping weight and if a 440 Dart is heavier than a Hemi Dart, then 440 weight is what you use.
I've communicated with NHRA on verbiage and they have changed the rule as a result. I'd suggest you do the same on this.

[Stewart Way]

Jeff
My verbiage isn't off. I don't have any verbiage. I'm just reading what NHRA has in its rulebook. But deep down inside I know your right on how they figure the weight. I messed up when I built my car. I built it to AH specs and used the 3020 weight and planned on running GT/D but with the heavier minimum looks like its a GT/F car and 305 lbs heavier.

[Jeff Lee]

So the 383 2x4 using an old Wiend tunnel ram didn't pencil out?

[SStockDart]

Hold on a second. OK, here is the senerio. You want to put a 1970 - 383 in a 1968 lightweight body. In the classification guide, the "lightweight" body is a Dart 2 door coupe. Not a 270, GT, or a GTS. Therefore, per the classification guide, the heaviest gasoline engine in the "2 door coupe" is the Race Hemi. The weight is 3,020 pounds. So, the 1970 383 is 304 HP. So, the factor is 9.93. That puts the car in GT/D. The minimum weight with the driver (to get to the bottom of the class), is then 3,058, rounded down to 3,055.

The shipping weight can be adusted up to 250 pounds to fit in a class. Using this senerio, the weight adjustment to fit in the class is 132 pounds, and perfectly legal. You could not get this combination into GT/C because that would be a 284 pound adjustment and over the 250 pound limit. This car could move down to GT/E. That is only a 20 pound adjustment.

Regarding lightweight components. The rules state: "Aluminum or other lightweight material may not be used to replace heavier items on car." No mention of replacing lightweight material with something heavier. Therefore, the literal interpretation is that is is legal to claim a 'lightweight' 1968 without having fiberglass fender, acid dipped doors and bumpers, and lightweight glass.

From a realistic perspective, if you want to run this car at the bottom of the class, you will probably need all of the lightweight "stuff". Hope this clears it up.