69 Chevelle AA/SA 10.04 at 125mphat Spring Nats

Dwight Southerland · 04-23-2017, 03:28 PM

This is interesting. I have a copy of the Class Guide sheet for 1969 Chevrolet that I downloaded on 1/25/17 after the end of the year factors were added. It shows the factor to be 8.50, which is consistent with the math (3611 ship wt / 425 factor = 8.49647, rounds to 8.50). However, if you look at the same sheet on NHRA's website now, that factor is 8.49 with no indication that any change was made on the sheet. (Dates are included at the bottom of each sheet that documents changes.)

For anyone who is Excel knowledgeable, the formula for that cell was changed from (8.3*435/Q272) to (8.29*435/Q272), so a change was made.

Here is the sheet from 1/25/17. Note the document date at the bottom is 1/1/17, the same as the current sheet on the NHRA website. Sounds like politics to me.

Larry Hill · 04-23-2017, 06:54 PM

If NHRA starts rounding the numbers, then NHRA will be changing the shipping weight. If the number is 8.4999999 it should be 8.49, just use the first two places to the right of the decimal point. Its so easy even a hillbilly can do it.

Dwight Southerland · 04-23-2017, 07:17 PM

Larry -
Except that the factors on the Class Guide sheets are rounded now. It's just that the odd cases where the number is on the break is it a concern. Also, I have class guide sheets for 1969 Chevrolet back to 2002 and they are all 8.50 for that combination.

Chipper Chapman · 04-23-2017, 07:32 PM

I'm building the 396/375 to run B with mine, the way I see the sheets the 427/425 is natural A. 427 would be one heavy old ride in B

Casey Plaizier · 04-23-2017, 08:05 PM

I'd really like your phone number.

04-23-2017, 03:28 PM	#1
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 2,001 Likes: 64 Liked 780 Times in 194 Posts	Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats This is interesting. I have a copy of the Class Guide sheet for 1969 Chevrolet that I downloaded on 1/25/17 after the end of the year factors were added. It shows the factor to be 8.50, which is consistent with the math (3611 ship wt / 425 factor = 8.49647, rounds to 8.50). However, if you look at the same sheet on NHRA's website now, that factor is 8.49 with no indication that any change was made on the sheet. (Dates are included at the bottom of each sheet that documents changes.) For anyone who is Excel knowledgeable, the formula for that cell was changed from (8.3435/Q272) to (8.29435/Q272), so a change was made. Here is the sheet from 1/25/17. Note the document date at the bottom is 1/1/17, the same as the current sheet on the NHRA website. Sounds like politics to me. __________________ Last edited by Dwight Southerland; 09-01-2019 at 07:56 PM.

04-23-2017, 06:54 PM	#2
Larry Hill Live Reporter Join Date: Oct 2004 Location: Hickory, Ky Posts: 10,648 Likes: 1,941 Liked 10,756 Times in 2,236 Posts	Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats If NHRA starts rounding the numbers, then NHRA will be changing the shipping weight. If the number is 8.4999999 it should be 8.49, just use the first two places to the right of the decimal point. Its so easy even a hillbilly can do it. __________________ IHM Used Parts https://ihmusedparts.com 888-821-1817

04-23-2017, 07:17 PM	#3
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 2,001 Likes: 64 Liked 780 Times in 194 Posts	Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats Larry - Except that the factors on the Class Guide sheets are rounded now. It's just that the odd cases where the number is on the break is it a concern. Also, I have class guide sheets for 1969 Chevrolet back to 2002 and they are all 8.50 for that combination. __________________

04-23-2017, 07:32 PM	#4
Chipper Chapman Member Join Date: Jan 2004 Location: Belmont N.S. Canada Posts: 473 Likes: 246 Liked 166 Times in 71 Posts	Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats I'm building the 396/375 to run B with mine, the way I see the sheets the 427/425 is natural A. 427 would be one heavy old ride in B __________________ Chris Chapman 1969 Chevelle NHRA F-G/SA 1090

04-23-2017, 08:05 PM	#5
Casey Plaizier Junior Member Join Date: Feb 2009 Posts: 6 Likes: 0 Liked 0 Times in 0 Posts	Re: 69 Chevelle AA/SA 10.04 at 125mphat Spring Nats I'd really like your phone number.