BillyShope

Yes, rear tire loading on launch can exceed the total weight of the car. Unfortunately, this lasts for only a few milliseconds and...to make matters worse...is preceded by a few milliseconds of decreased loading.

An extreme example would be a car with severe squat and very low rate springs at the front. The rear of the car goes down and the front pops up. In other words, the whole car is pitching (rotating). At the beginning of this pitch motion, the rotating inertia of the car in pitch is overcome by a moment generated through the front and rear tire patches. This moment is opposite in direction to that associated with weight transfer and is therefore "hurting" performance. As the car's pitch approaches its extreme position (maximum squat and maximum front end rise), the car's angular velocity must be brought to zero. The inertia again comes into play, but, this time, the moment is in a direction favorable to rear tire loading and it is at this time that it is possible for rear tire loading to exceed the total weight of the car. Again, we're talking milliseconds for this "extra" loading. (Typical pitch inertia for a 3000 pound car is 6.5 million pounds mass inches squared.)

And, a bit of history on that NHRA crankshaft height rule: Although I can't prove it, I don't...for a minute...swallow the "safety" excuse. As you old timers might recall, it was the Ramchargers' C/A that started the "higher is better" theme. (This was due to the poor slicks available at the time and is certainly unwarranted today.) The car became so dominant in its class that, when they showed up at a strip, the Chevy-powered cars would often not run as a way of protest, claiming that it wasn't fair that they should have to run against a "factory" car. This didn't make the strip owners very happy, as they had probably featured the presence of the Ramchargers in their ads. Anyway, I don't know if it was pressure from the strip owners or from GM, but, at the same time this "safety" rule was passed, another change was made to lower the pounds per cubic inch number for C/A which, of course, allowed the Ramchargers' records to be taken by GM-powered cars.

lively

BILLY----I WILL SECOND THAT RAMCHARGER STATEMENT---THAT IS WHY THE GASSERS MOVEMENT CAME OFF THAT SAME THEORY 8) 8) --HIGH SUSPENSION AND ALTERED WHEELBASE MADE TRACTION BUT AT TIMES SCARY RACING!!!! :? :? :lol:----I JUST LOVE IT---- LIVELY

edvancedengines

Hey Mr. Billy,
Post a pic of that thing. Post one of the ones you sent to me. It was really far out for it's time in history. Also I don't remebr exactly which years it set the C/A Records. I know it was way before the Super/Stock wars.

If you will look deepr into that last post of mine and see if in your opinion my theory about the constant rising center of gravity as the car goes higher and higher as it goes down track is making any sense to you.

Some of these Nitrous and Turbo cars continue to climb the further down track they go. I know of drivers while they are in the air tapping their foot on the brakes in attempts to bring the front down but still stay on the pedal becuase they still are trying to win a race.

This seems to happen more in the radial tire cars that have to dead hook to launch. It also does happen with a few of the Outlaw 10.5 cars too though. It gets to a point like almost the front weighs nothing until it comes down again.

Care to comment?

Ed

lively

ED--THERE IS A POINT OF BALANCE AT SPEED THAT HAPPENS ON MOTORCYCLES AS WELL AS CARS---WHEN I WAS A YOUNG BOY I USE TO PULL WHEELES ON MY STINGRAY BIKE AND COULD FIND A SPOT AT SPEED TO KEEP THE FRONT BALANCED FOR LOOOONG DISTANCES AT TIMES---SAME WITH A DRAG CAR --DON'T KNOW THE FORMULA TO PROVE THIS BUT HAVE SEEN IT MYSELF IN RACE CARS---THERE IS PURE TRACTION BUT VERY LITTLE CONTROL :shock: :shock: :shock: -LIVELY

BillyShope

Okay, Ed, here's a picture:



They were setting and resetting the speed and ET records in '60 and '61.

As for your comments, I can only say that, for a "normal" car, the acceleration is a maximum on launch and then decreases during the run. For a AA/FD, with that big wing providing more tire loading, the acceleration increases at the top end. For a full discussion of "blowovers" and the forces acting on the car during launch, I'd recommend readers take a look at "Getting Started" (Page 1) of:

BillyShope

A clone of the car pictured above was recently built by employees of Chrysler Daimler as a tribute to the Ramchargers. The original was parted out as a result of the crankshaft height rule. The clone presents the car as it first appeared...in primer...at the '59 Nationals. (Best speed in its class first time on the strip.) The picture below was taken at the 2007 Woodward Avenue Dream Cruise. If you look closely, you'll see that the exhaust cones are at a slightly smaller angle than the original. Other than that, it would be difficult to find any difference. Of course, original Ramchargers living in the Detroit area oversaw the reconstruction and kept it authentic.

The fellow in the white t-shirt MIGHT be Pete McNichol, but I'm reading an awful lot into very little information. (Pete garnered quite a few NHRA records in different classes, but with the same 170 cube slant six.) Don't recognize the old timer on the right. Probably just a spectator.

edvancedengines

Mr Billy,
A few unrelated questions. (Thread Hi-jack)
Who is still left from the Ramchargers Team?
Was Al Eckstrand a part of the team or independent with factory help?
Did the Ramchargers and the Golden Commandos share in information or share anything and were they friends?
Was the 2% cars your idea?
Was the heavy filled tires your idea?
Was the extra weight added up real high your idea?
Was the thin lightweight trunk lids your idea?
Did the High & Mighty have a 354 cu in or smaller?
Were you at Cecil County in 1965 the night the Injected Car ran into the 8's as the first 8 second doorslammer? I was there that night.
We had tons of match racers there.

Ed

BillyShope

To my knowledge, all but one of the original group are still around. Of course, at our age, a day-to-day check is probably necessary.
No, he was not a part of the Ramchargers, but he definitely received factory help. Chrysler has been "helping" since Arnie Beswick's D-501.
Any competition would have been on the friendliest of terms and, yes, they definitely shared information.
No.
No. Probably Barnes Daniels. He used a concrete-filled continental kit in his E-Gasser.
Now, this is an interesting question. I was discussing the problem with either Dick Burke or Fred Gluckson and we were talking, specifically, about the moment created by the inertial force when our eyes "lit up" at essentially the same time: Of course! We can't do anything about the overall weight, but we can certainly increase the moment by raising the CG!
No.
It was a 354 with 392 heads. Now, I know someone is going to say that the 354 heads are better. All I can say is that this was done with the knowledge and consent of Tom Hoover. The clone, incidentally, has a 392, but it will only be allowed exhibition runs, anyway.
No. By that time, I was working for the General. I had gone back to school for a couple of years and then taught at the General Motors Institute.

Bubstr

Now I have a tear in my beer over days gone by. I remember them days too. Took my first car to the strip in 58. A 49 ford business coupe, with the flat head.

I feel sorry for the youngsters. Bore job 4 dollars a hole solid lifters a buck a piece Offenhouser heads 59.99 a pair. A good seasoned block from the bone yard A few bucks and you was a racer.

Billy tell them, back then it was illegal to have a locked or welded rear, although we both know there was a few of them around. The big money and bracket racing took the fun out of it kinda.

edvancedengines

Bubstr,

(off topic post)
People now will never know the excotement of two dragsters/roadsters/coups etc pushing down to fire up and them coughing to life at the last minute. If they didn't fire that was it the ball game was done and you lost.

The 1964 1965 and up Match Race wars with wheels up burnouts through the rosin or the bleach. Dandy Dick Landy doing high wheelies during burnouts and then the front weels barely coming up in the race. Don Nickolson's Comet with long rear wheel opening so they could move the rear forward or backward to tweek it in to the tracks. That was neat. Carried several different length driveshafts with tem and the rear subframe was movable with the 2 x 3 Rectangular ATorque Bars weled to the housing.

AA/Fuel Roadsters doing 4 wheel wheelies. or blazsing the tires 3/4 of the track. Fuelies smoking 3/4 track with high gear only using an in and out box.

None of those only fun times are seen now. They were unforgettable and exciting.

Ed