Hooley's spin video....

[John Burk]

Sum
How about this theory . The early wandering was wheel spin . Tires got hotter and hotter till lost grip led to spin/save which further heated the tires . The diminishing pull of the chute and still hot tires lead to the later spin . The ballast reduced wheel spin , tires didn't heat and the handling improved .
John Burk

[Glen]

What tires was he running on the rear?

[Sumner]

Sum
How about this theory . The early wandering was wheel spin . Tires got hotter and hotter till lost grip led to spin/save which further heated the tires . The diminishing pull of the chute and still hot tires lead to the later spin . The ballast reduced wheel spin , tires didn't heat and the handling improved .
John Burk

I feel at 3200 lbs. the car was just too light and at 223 (speed at spin) it was getting to the point where there just wasn't enough weight on the rear for the traction needed to overcome the aero drag.  He had some wheel spin before the spin, but looking at the RPM data it didn't look like it lasted very long.  With most cars with a fairly short wheel base spin is probably going to induce the back wanting to pass the front, which to me always seems strange as you would think once the back loses traction it would fall further behind, but numerous tests on snow coverd roads in Wyoming failed to confirm that theroy .  Your theroy might also be right, but the correction regardless is more weight.

What tires was he running on the rear?

They are Goodyear Land Speed 28 inch tires.  After the spin the car did have to be re-inspected (thanks for reminding us that day) and there appeared to be no flat spotting or damage.

c ya,

Sum

[Stainless1]

I emailed Bob Stroud, he saw the video and needed a little more info.  One of the crew should contact him.  His email below:

bstroud@sbcglobal.net
Nice photos, but it looks like the chute did keep him from looping, but
there was no mention of how fast he was going. The faster he goes, the
better the chute works, as well as reverse. Let me know. Bob

Just having fun in retirement....

[WZ JUNK]

Sumner is going to try to make contact with Bob today as he passes through OKC.  He may get there to late in the day to catch Bob.  I am glad that Bob has seen the video as were are curious as to what he thinks.  I am speculating that the last part of the spin seems quicker because the parachute is not inflated as much as it was at first but I am just guessing.  

Thanks for the help.

John

[bbb]

would two chutes be beneficial for air braking? broadening the air mass vs circumfrencially increasing it? have you moved weight at all since the near miss?
great video too.

[Glen]

BBB
There are some that run two chutes but usually a high speed and a lower speed chute. Getting the chutes out before one is to far into the spin is what counts.  If the vehicle is already 90 degs' to the course one chute would get into the other and collapse both. It's not like drag racing, cars on the salt can loose traction fast and the driver has to be on top of it to save it from spinning or just go along for the ride.

The reaction time to dump the chute and till it opens and has a lot to do with how long the tow line is. I have seen many chutes come out but the car is already 180 degs to the course and usally ends up wraping the chute around the car.

[sirstude]

Sum,  I know you are on the road, but when did the chute catch the push bar?  Since you had to straighten it out, I am assuming it was hooked.  When you see the ProStock drag race guys have problems at the big end with swapping, the talk about hooking the chute into the wheely bars quite often.  Seems to make them want to swap ends.  The Stude did seem to start whipping late into the "spin".  

Just wondering
Doug

[WZ JUNK]

Sum,  I know you are on the road, but when did the chute catch the push bar?  Since you had to straighten it out, I am assuming it was hooked.  When you see the ProStock drag race guys have problems at the big end with swapping, the talk about hooking the chute into the wheely bars quite often.  Seems to make them want to swap ends.  The Stude did seem to start whipping late into the "spin".  

Just wondering
Doug

I will try to answer for Sum.

We think the car ran over the parachute cord at the very end of the spin as it was moving backwards over the boundry line of the course.  We have studied the videos from outside the car and the car seems to bounce at about this point and it may be when it goes over the cord that it causes the car to jump or bounce.  I think that it was either at that point or at the end of the left turn at the end of the spin when the car was nearly backwards going down the course.  I am hoping that the offical photographer for the event caught the spin and he has included it in the as yet unreleased 2006 Bonneville video.  I would like to study that video.

John

[Sumner]

Just an update:

I talked to Bob Stroud on the phone last week just before I started home.  He had just seen the video of the spin (probably after Stainless sent it to him, I'm guessing).

He doesn't recommend us doing anything different with the chute.  He feels a bigger one would hit too hard on normal runs.  He did mention the possibility of a second bigger one, but then you run into the problems that Glen mentioned above.  So I think Hooley is going to stay with what he has.

   

As mentioned above the bar (roll bar tubing) that the chute attaches to was bent to the right at about the point of the arrow in the picture or a little closer to the receiver it goes into.  It was bent about 45 degrees.  Up to this point we have assumed that the car spinning ran over the chute lines and bent the bar.  I no longer believe that is what happened.  When the car started to spin the back went to the left (west) and Hooley got the chute out in less than 2 sec. from the start of the spin.  So about the time the chute hit the ends of the lines the car was about 45 degrees to the track.  I think it was the initial opening of the chute and that impact that bent the chute attach bar 45 degrees to the right.  Remember that the car was going 223 mph when the chute blossomed, so that would be quite a pull on that bar.

For next year the bar will be modified and will be triangulated.  If you have a car or you are building one you might want to look at your chute attach point and visualize the forces on it if the chute deploys and the car is not going straight.

I have looked at this video (  http://www.youtube.com/watch?v=eixUJA-scBU&mode=related&search=   ) a number of times as at the 3 min 10 sec. mark it has the end of Hooley's spin.  Looking at the chute lines next to the car where they are wrapped in white material to me it looks like they never go under the wheels, but my monitor is not great, so if someone sees something else please let me know.

The car does appear to start to lift at the end of the last spin in the video to me, but watching the video from the back of the car the horizon never seems to tilt.  Also just after that the chute starts to collapse and drop towards the ground.  This is when I first though the car ran over the chute, but now I think the car was going so slow at this point that as the car swung back towards the chute the line just started to go slack.

I got the rest of the video from the other cameras from John when I was in Missouri and there is some neat stuff there.  We have the view out the front of the car during the spin and also a view of Hooley getting the chute out and sawing on the steering wheel during the spin and the rescue crew arriving.  It is nice having those guys out there and knowing how quick they are, thanks guys.

c ya,

Sum