I "think" it's about 1.0 second for the 60 foot time.

0-100 MPH happens in about one second as well according to
"The Learning Channel" (< good source of info? )

 

The 60' is indeed in the 1 sec. range, obviously it's a matter of traction not hp. I wonder how you would calculate the 60' if it were possible to "dead hook"?

Rich Krause

 

That's how I took it. Not much paranoia here.

 

A 1.0 sec 60 ft. time equates to about 3.7 average g's.

A 1 sec. 100 mph time equates to about 4.5 average g's.
That would equate to a 60 ft. time of about .82 seconds.

4.5 g using only tire traction ain't bad. Well, by 100 mph there is significant down force.

4.5 g on a 2200 lb car(?) is about 10,000 lbs of thrust. With a 16 inch loaded tire radius, I get 12500 lb-ft. at the tire. With a 3.20 screw thats about 3900 lb-ft getting thru the clutch. That's about where I figured torque at 8000 rpm. That's close to a "dead hook". These are averages for the first second or so and we're estimating hp's of course. My guess is that tire traction technology and hp production are running in step.

FWIW, With 12500 lb-ft at the tires, why no wheelstand? The front wheels are 300 inches or 25 feet away, so 500 lbs on the fronts will balance the 12500 lb-ft. If a TF car is about 23%-77% static distribution that's about 500 on the fronts.

I think I got the math right.

 

A TF dragster will 60' around .80, a Top alcohol dragster will 60' in the low .90's. High 6 second/low 7 second cars usually 60' around 1 flat. I don't know about 1/8 mile ET, but on a good pass TF dragsters run over 270 to the 1/8, a Top alcohol dragster around 220.

 

No, I was thinking about Astrolite G and A-1-5.
(Hammas is supposedly experimenting with astrolite soaked clothing instead of the traditional bomb vest, as a way of being stealthier.)


McVeigh supposedly used ammonium nitrate and nitromethane anyway.

Not that I believe the govt's story. The crater under the truck wasn't consistant with a low brisance explosion (<21,000fps), the supposed design was about as inefficient as you can get and the BDA was inconsistant with the laws of physics anyway. Under the "official" version of the story anyway.

But I think that's enough off-topic public discussion on this "touchy" subject anyway.

If you want to continue discussing this subject, which is fine with me, I suggest we take it to PMs.

 

Wicked's numbers are closer to real life. A 1.0 60' time for a fuel car would be way off the mark.

 

Does anyone know what the coeffeicient of friction between the tires and ground is? I remember in one of my physics classes they mentioned that is is one of the highest friction coeffiecients of any two surfaces in the world but they didn't have a number.

 

According to Milliken & Milliken in Race Car Vehicle Dynamics:

"The rubber is stuck to the road by a variety of mechanisms including mechanical 'gearing' to the texture of the pavement and molecular adhesion to the surface. These mechanisms are not totally understood."

If you assume ~4.5 g's at launch with negligible downforce, the effective coefficient of friction would be ~ 4.5. (edit) See brent's post below...

I like this quote, perhaps from Maurice Olley(one of my heroes, FWIW):

No living thing but a snail has as good a shoe as a motor car

 

I was going to comment earlier how interesting and significant i found that. Because the tarmac is smooth the mechanical gearing aspect can't be very large. The molecular adhesion of hot sticky rubber alone isn't coming close to bumping that up to 4.5.

-brent

 

Good thought. A couple of thou downforce would halve the apparent mu, wouldn't it? ~2.5 sounds more plausible, huh?

 

to the people comparing it to the 747, that's 240,000 pounds of thrust, not horse power you have to do a conversion that escapes me at the moment to convert it to HP

 

To answer:


I submit from Page 1





Chris

 

i want to mix some of that nitro in my gas tank

 

I would guess it would have the same effect as putting 94 or 110 in an engine made for 87, would burn too slow for the compression to do anything, but I could be wrong since it is a totally different fuel.