Ol' Fart's Firebird Fantasy

[oldskool]

OK, the Catalina was the same size as the Bonnie, but had a different grill. They also had the same fastback roof line in the 2-door models. So, one of these will do just as good.

The '78's had a different grill than the '77's. I found a '78 on the track.

What do ya'll think would be the chances of finding one of these old cars in usable condition ?

[oldskool]

Then, of course to make N/SA @ 14.5 lbs/hp, would require a wagon or a GP SJ. But because of the lack of side vision, I've decided not to use a GP.

http://www.classracerinfo.com/Engine...spx?ENGINE=764

http://www.classracerinfo.com/NHRA_Classes.aspx

Either a Cat or a Grand Safari wagon would do nicely, and have PLENTY of side vision. Besides having more weight over the rear tires, the extra side vision is another advantage of using a wagon.

[Dave Gantz]

I have nothing to offer, I just wanted to say that if enthusiasm were equal to wins, you'd be number 1 in points every year!
Good luck with your project.

[oldskool]

Thanks !

Now I need to ask a rear end question. Does anybody know if these '77 Cats and Bonnies had the 8.5" rear ?

I know the '71-'81 Birds and I think the '71-'74 Ventura had the 8.5. I have one in my '74 Vent bracket car, and it seems plenty strong for a low 12 or high 11 sec car. But I've read that some of the lower powered Vents from the later '70's had the smaller 7.5 rear. Just don't know about the Cats and Bonnies.

I've read that these big tens are almost as strong as a 12 bolt and will do just fine at this level of racing. I've never broken a stock axle. But I reckin NHRA requires aftermarket axles and / or C-clip eliminators. Is this correct ?

[Mark Yacavone]

Originally Posted by oldskool

Then, of course to make N/SA @ 14.5 lbs/hp, would require a wagon or a GP SJ. But because of the lack of side vision, I've decided not to use a GP.

http://www.classracerinfo.com/Engine...spx?ENGINE=764

http://www.classracerinfo.com/NHRA_Classes.aspx

Either a Cat or a Grand Safari wagon would do nicely, and have PLENTY of side vision. Besides having more weight over the rear tires, the extra side vision is another advantage of using a wagon.

You just need a Bonneville 2 dr. to make N/SA.

Had one for sale here a couple of years ago..Cheap roller.
No calls..No notes...Scrapped it!


Yes 2 dr. should be 8.5 ..Watch the wagons..They had a weird one..2 inches wider too.

[oldskool]

Originally Posted by Mark Yacavone

>>>>>You just need a Bonneville 2 dr. to make N/SA.<<<<<<


Yes 2 dr. should be 8.5 ..Watch the wagons..They had a weird one..2 inches wider too.

I must be missing something here. If I'm reading this info correctly, it says that the weight break for N/SA is 14.5 lbs/hp, with an index of 13 flat.

http://www.classracerinfo.com/NHRA_Classes.aspx

This page says a wagon hits 14.50 right on the head, @ 4103 lbs. But I got out the calculator and it says that in order to get those figures, they'd have to be using the 283hp factor for this engine in a Bird.

http://www.classracerinfo.com/Engine...spx?ENGINE=764

But the info on this page clearly says that the 180hp 400 engine was only factored at 283 in the Birds. It is factored at only 260 in everything else. So if this ain't so, now I'm really confused.

http://www.classracerinfo.com/Engine...spx?ENGINE=764

So am I just reading the info sheet wrong ? Or, are their calculations wrong ? Shouldn't they be using the 260hp factor for this engine in the Cats, Bonnies and wagons ??? If this info is incorrect, where exactly can I find the correct Stocker info ???

OK, assuming that the hp factor of 260 is correct, Then a 2-door Bonnie Brougham with this engine would have a weight factor of :

3689 lbs / 260hp = 14.19 instead of the 13.04 listed on the Class Racer Info page. So if this is correct, then you could just add weight to make the 14.50 lbs/hp break, which will be an N/SA.

14.50 x 260hp = 3770lbs - 3689 = 81lbs difference

So, you'd need to add 81 lbs to the shipping weight of the car to make the 14.50 weight break.

So. exactly how would I go about finding out if the hp factor is listed wrong on the sheet, or the calculations are done wrong, by using the 283 Bird hp factor for the engine ?

It would be a shame to build a car, going by incorrect info, only to find out at your 1st event tech, that you will be in a completely different class than you planned and built for.

[oldskool]

OK, unless and until I hear different, I'll assume that the 260hp factor is the figure to use when doing class calculations for everything except a Bird in '77. And, as of now, I'll have to use the shipping weights listed on these Class Racer info sheets. But I'll ignore their weight break calculations and do my own with a calculator.

So, by using this method, it appears that the highest class that could be run with this engine in a non-Bird is with a Cat 2-door.

3601 lbs / 260hp = 13.85

So, if I understand the rules correctly you can take out weight to meet the minimum for the class your car naturally falls into. Or you can take out more weight to meet the minimum for the next higher class. Or you can add weight to make the next lower class. So, that means that most cars can run any one of 3 classes just by adding or removing weight. Is this correct ?

If so, then the 2-door Cat I mentioned will naturally fall into the 13.50 weight break class, which is L/SA. Or, I can remove weight to meet the minimum for the next higher class which has a 13.00 weight break. This will be a K/SA with an index of 12.65.

13.00 x 260hp = 3380 lbs

3601 - 3380 = 221 lbs

If my calculations are correct, you'd have to remove 221 lbs from the 3601 lb shipping weight, to fit the 13.00 lb/hp weight break perfectly. Is it legal to run that far below the shipping weight ?

Just out of curiosity, what year did NHRA start allowing you to add and take out weight to make different classes. Before they did this, did they 1st just allow you to remove weight to meet the minimum for your natural class ? Or did they make the changes all at the same time ?

When we ran Stock, the car ran at no less than its shipping weight--period. What ever class it naturally fell into, that's the class you ran with that car. That gave some cars a weight advantage. We ran a 330hp '68 Bird with a 3300 lb shipping weight. So it was a perfect fit for the 10 lb/hp weight break--E/SA.

[Mark Yacavone]

http://www.classracerinfo.com/CGPage...7&MAKE=Pontiac

Dwight's site is not incorrect.
It's the operator that's incorrect. LOL

Just look up the body style, one at a time..You are confusing yourself the way you are doing it.

[Danny Ashley]

That chart is wrong concerning the 77 Cat wagon. A 2 seater falls at 15.72 and a 3 seater 15.78 .Both natural O cars. Minimum O weight with driver is 4070. The 2 door Cat falls at 13.85 natural L car. 13.5 X 260=3510 + 170=3680. K would be 13 x 260=3380+170=3550. a difference of 130 lbs. M would be 14 x 260=3640 + 170=3810. which is 130 lbs above your natural L weight. Use the NHRA classification guide instead of those charts and you won't go wrong.

[oldskool]

Originally Posted by Mark Yacavone

http://www.classracerinfo.com/CGPage...7&MAKE=Pontiac

Dwight's site is not incorrect.
It's the operator that's incorrect. LOL

Just look up the body style, one at a time..You are confusing yourself the way you are doing it.

OK, thanks for the info. I've never seen that page. Don't know yet how to call it up. But I don't understand why the non-birds are shown with calculations using the 260hp factor on this page that you linked, and the 283 factor on the page I was looking at ? It just appears to me that it is not possible for both pages to be correct. Seems it has to be one way or the other ? But then, what do I know ?