pls help with classification math
 

in another thread
http://classracer.com/classforum/showthread.php?t=8643

I made an offhand coment about weight of the 72 G/SA Buick shown for sale on the ebay listing. the car has semingly substantial weight addition capabilities, noted by another poster, and having owned several of these cars (no stock/superstockers, just street and bracket raced vehicles) I am pretty familiar with what they weigh, so I got to wondering and then researching where this car actually falls in NHRA rules. According to NHRA Classification guide, if I am reading it right for 72 GS 455, (and I readily admit to knowing ittle about how it actually works,except apparently If someone could get a letter from carrol shelby they could do whatever they want) this engine carries a hp factor of 330 and the weight classification of 10.97, making it an E/SA at best, with a 3620 required weight, and if I understand it, you could add a little weight and drop to F/SA, how would it get into G????

Re: pls help with classification math
 

10.00 is a natural E Car, the break is 10.97 which makes it a natural F car. So it can run E,F,or G/SA by rule

Re: pls help with classification math
 

thank you tony, apparently I did not understand the breaks, and thought it was a natural E car. Then you can remove weight and go up to E, or add to go down to G-think I get it now!! Thanks again!

Re: pls help with classification math
 

Stage1scott to further clarify the classification, to run the Buick in g/sa the min. weight with driver would be 3800lbs. Multiply 11 (G factor) by 330 (rated HP) and add 170 for driver. I have a 71 GS that I ran in G/SA and I had to add weight to achieve 3800. When I ran it in F/SA a few years back I could just barely get it to mimimun weight and that was when the HP rating was at 335(I think it came down in 2002). This past year I ran SS/LA with the stocker motor and my min weight was 3875 and I had about 240 lbs of extra weight added to make the min weight. Hope this helps some.

Re: pls help with classification math
 

hey Johnny, thanks that helps even further. and makes me see the reason for a weight box. My low 13 second street car (72, a/c,cruise, drag radials) weighed 4138 with me in it (190 lbs) and a half tank at fontana in november, so I could see 3400 lbs in an "empty" race car, although it would take some weight loss concentration to get to D wieght in a 70, I guess. what rear ratio does it take to move these things competitively? at these weights? and also, since my interest is now all over the place, what cyl heads are you allowed in SS? still the cast iron heads, with small valves for the non-stage 1 engine?? but any camshaft/rockers?? thanks for the info in advance, I am always stunned at how fast legal NHRA stock and super stockers are these days, and a being a Buick owner/enthusiast, am interested in how these cars are running in the curent rules structure. Someone over on V8 Buick.com told me Jason line's old car is in the pacific northwest, D/SA, has run some 10.40s!!! that is just amazing to me!

Re: pls help with classification math
 

I use a 4.30 gear in my stocker/ss car. Also a 2.75 low gear in the trans helps immensely to get the car off the line but with the 4.30 rear it keeps the trap rpm around 6000 to 6200 rpm. I believe that Jasons old car is now owned by Alf Wiebe and I heard that that thing has been in the low 10.30s if im not mistaken. In SS you have to use the cast iron heads for the year that you claim, small valve if you use the 330 hp motor or you can use the stage one size valves but the HP rating is higher and it will put you up 2 classes at approx. the same weight. Talk to you later.