Weight vs ET
 

If you lightened a car 150 lbs what would the ave gain in ET be???

Re: Weight vs ET
 

The approximate number has always been a tenth per hundred pounds, but there are variables of course....I always use the Wallace Calculators for quick reference and know many others do as well; here's the link

http://www.wallaceracing.com/Calculators.htm

Re: Weight vs ET
 

I used following data on wallace

ET 10.05
MPH 130.00 at 3050lbs

wallace says at 2900 lbs

ET 9.88
MPH 132 and change

Ok why then does NHRA list SS/G at 10.45 index SS/H at 10.50 SS/I at 10.55 etc
difference in weight from H to I is 150lbs yet only 5 between indexes????????????

Re: Weight vs ET
 

Because physics didn't create the index system. ;)

In my 4-cyl FWD car, 215 pounds was nearly HALF A SECOND, in the 1/8th mile! If I recall, a similar change in my Volare was about .12 in the 1/8th.

Re: Weight vs ET
 

Good answer Michael.... Index system was created by Man and then hit/altered by man and his race cars performance!

Re: Weight vs ET
 

Ok why then does NHRA list SS/G at 10.45 index SS/H at 10.50 SS/I at 10.55 etc
difference in weight from H to I is 150lbs yet only 5 between indexes????????????

Ed, the REAL reason stems from way back and the answer is two words: Danny Helmer.

Jerry

Re: Weight vs ET
 

From everything I have been told, that is correct. Before AHFS, HP and or index was adjusted heavily when one racer dominated.
I can run SS/G-H-I just like you. Kind of makes it a difficult decision which to run, huh?

Re: Weight vs ET
 

Jeff it doesn't make sense. H is at 3010. Why in the hell would you add 150 to get to I at 3160. So one guy was fast why did it effect all the indexes. Why didn't they hammer his combo? That's what they did to Robin Brown with the 283 stick in 07'

Re: Weight vs ET
 

I guess that's just the way it is. Why don't you contact NHRA and see what can be done about it? Call NHRA Tech and ask for Pat Cvengros as he's the Committee Chairman of the S/SS Rules Committee.
Seriously, nothing will come of this posting here, you have to go to the source.
While your at it, get the stick indexes in line with the automatic indexes. For example, there's a .200 spread between SS/J & SS/JA. That's ridiculous!

Re: Weight vs ET
 

Jeff I did send a letter to NHRA a couple of years ago. They basically said to pound sand. My car needs to get the 299hp reduced. IHRA is 295hp. The 327/275 combo has been beat on for over 30 years. There's not alot left to be found in the horsepower dept. Were going to try a set of the RHS aftermarket heads this winter. But guess what the hp rating goes up to 304 when you do that. So well see.