BACKROUND
Well, I haven't posted on here in about 5 months since I have just been daily driving my vehicle. I used to drage race and bracket race, and I also firefight.

My firechief owns two rail car alcohol dragsters. One is a 355, powerglide, cammed to hell rail car that runs 5.50's in the 1/8 and one is a 454, alcohol injected blower rail that runs 4.80's-4.90's @170-180mph.

I run the 355 one and he runs the 454 one.


QUESTION
I was wondering if anyone knew a G-force calculator online that we could put in our 60 foot times and MPH and see what our approximate G-forces would be on takeoff.




(I know it's off LT1 topic, but I post on here alot and I figured you guys could point me in the right direction. We tried doing physics, and I am studying engineering, but it isn't working out right...I'll buy my own "Stupid" sign now.)

 

I'll look around. I know there is one out there somewhere as I found it a couple of years ago.....

 

Johnny,

I suspect that there will be substantial variations in G readings depending specific vehicle parameters but, the RacePak datalogger in my 2900# Firebird routinely records G forces in the 1.95-to-2.0 range on runs with 1/4 mile ETs in the 9.90s, 60' times in the high 1.2?s, and top speed in the range of low-to-mid 130s. Hopefully this data, combined with whatever else you can dig up will help you form a basis for extrapolation.

c

 

Yeah, I had tried digging it up online but haven't come up with anything. I pulled out the ol' physics book and did some "cyphering" and came up with a 3.2 instantaneous G force on immediate take off when you pop the trans brake, with average G forces coming in to the 2.7 G ballpark based on initial acceleration in the first 60'.

I figured the pull would be the greatest in that particular distance range, and helped to have an accurate time reading off the timeslip.

Seems like a lot of work for something the firemen up at the firehouse were just talking about. At least we know the general ballpark, but an online calculator, while not specifically accurate, might be fun to play with.

Anyone that finds one, lemme know. Thanks!!

 

Using a basic physics formula one can come up with a ballpark of what kind of G's you will be pulling in the first 60 feet. This formula assumes that the car will have a constant acceleration rate between the starting line and 60ft marker. In the real world most any car won't, but this formula is close enough.

The following is a basic formula from physics:
X=.5at^2

X is the final position (or 60ft marker), a is the acceleration (or G's with reduction) and t is time.

Plugging in numbers and simplifying the formula results in:

3.73/(t^2)=g

Plug your 60ft time in for t, then you will be able to solve for your G's in the 60ft (g).