Zorro and Streetrod, if this had to do with aerodynamics. Why didn't any other vehicles using chutes launch in the air and cartwheel?

I'll say aerodynamics had a little bit in this. But as you can see from the comments, brakes were a big part of the problem.

 

^^^^+1, Just about every journo that tested the car said the carbon breaks were very grabby which isn't something you want when slowing down from high speed....but on the flipside, better aero would've stablized the car during the first application of braking...

 

^^^ I also heard that he deployed the chute AFTER he hit the brakes. Some folks say you GOTTA drive through the chute release before braking. I've NEVER pulled a chute on a car, so I just don't know. Plus given the varying mounting points etc, you gotta have a chute designed for your car. Don't know if this one was or not.

John Hennessey had the following to say:

"Speedway chutes for places like Bonneville, etc. have a much longer shutdown. Goliad is somewhere in between at 3000 ft. We ran a speedway chute on our Viper Comp Coupe that was designed by Stroud. It had a tether that was probably 3 times as long as a drag setup and the chute size was probably 30% smaller. It was designed specific to our application. The smaller chute and longer tether do not hit as hard (decel g's) as a drag setup. Also, when using a chute the driver should be full on the power when pulling the chute. That way the power and force of the car control the chute and the direction. If you lift off the power then deploy the chute it could pull you where you dont want to go. I only brought this up as it seems to be happening more and more. Guys take a street car, start going fast, add some safety equipment but in reality their cars were never designed as race cars. If nothing bad ever happens or you dont crash then no big deal. However, if you race long enough then sooner or later something is going to happen. And the better your safety equipment, design and application, the better you have a chance for survival. I dont have all of the answers but I have seen a lot over the last 20 yrs. I would suggest that anyone who is serious about running big speeds at the mile then they should build their cars to SCTA-BNI (Bonneville) safety specs."

 

Ok let me clarify my comments.

First off if he had an issue with his brakes why go for a high speed run where any failings in the brake system are going to be exaggerated?

Also any car using a parachute to help it stop is going to be open to the possibility that wind will cause a possible blow over or destabilise the car during deceleration. Also as I mentioned before a chute causes an acute shift in the cars aero balance. This effect can become a lot worst if the chute was not attached to the right place on the car. A few inches in the wrong direction can have a huge effect on the way the car reacts.

As for not effecting other cars again this could be down to a number of factors ranging from the size of the chute, wind conditions, location etc etc.

What I do question is why these cars had chutes in the first place? Why don’t they have a brakes good enough to stop them if they are capable of these speeds?

One last point, two of the fastest production cars that have been built, the Veyron and Mclaren F1 both have something in common, an airbrake. This deploys when you brake from high speed to keep the centre of pressure over all four wheels so stopping the tendency for the car to pitch forward and unload the rear wheels so causing instability. This is an aero function.

The new MP4-12C also has one.

I don’t expect these guys to go out and produce an airbrake for a Gallardo, but if you expect to run a short wheelbase car at speeds it was never designed for then expect at some point something bad can and will happen. There is a reason why land speed record cars tend to be long and spinderly

 

Wow!!, its not often that I agree with anything that John Hennessey has to say but he is absolutely on the money with his comments above which also echo my previous comments.

Any car travelling in excess of 220 MPH say, just by taken your foot of the gas at that speed you will be hit by about a negative 2+G in deceleration. Add a chute to that has caused people in the past to detach a retina. Aerodynamics at these speeds are a bitch just waiting to bite your head off. Ignore them at your peril

 

Read above. At those speeds, you're so on the limit that it doesn't take much for things to go out of control.

Sure, in ideal conditions, you can go up to 250 and back down to zero safely.

Add in a bit of crosswind, grabby brakes, a chute that isn't set up or timed properly and you get carthweeling because you're on the edge so much.

A Veyron was designed for 250, and you don't need chutes or other ghetto-isms to slow down. Because hundreds of people worked for years on obtaining a safe stable deceleration.

There's a vid on the Youtubes of a Lancer Evo going 180mph (not sure of the actual number) and the back instantly steps out the second the driver lets off the gas.

A 747-400 only needs 180mph to take off and weighs 360 tons. You're in a 2 ton road car doing 250 ... and doing all you can to stay on the ground. It's a razor's edge thing.

 

Insane pic, its great that he walked away from it though.

 

As a few others have said I don't think this had anything to do with Aerodynamics in the sense you are looking at it in. I was there to see the accident with my own eyes along with two other teamspeeders at the 3/4 mile mark. The car was dead stable until the chute deployed.

The shutdown zone at the mile is relatively short. .5 mile. The very end of that .5 is not the best surface in the world and I suspect Richard may have just hit the brakes a little harder than he should have. The stock brakes are up to the job as Jonah, Kyle and Richard have proven over and over again at the mile. Its only the "exciting" runs that a majority of the people not attending get to see. These cars have made close to a 100 drama free passes in the last 18 months at the mile.

Chris,
When the heck are you gonna let Eric drag you down to Texas. Surely you've had long enough to come up with a good enough excuse so I can't wait to hear it .

With that said Richard has plenty of drag experience as well as experience using a chute. He has competed at a very high level as far as drag racing goes. Saturday's incident seems to have been a very unfortunate accident. Richard made it out unharmed and that is what counts.

I think it had to do more with the way the chute was mounted and the rear weight bias of the Gallardo more than the true aero of the car. I have no person experience with chutes but the only cars I've seen have issues with chutes at the mile are rear engined cars.

Again because the videos that get posted are the more "exciting" passes you'd think that every run was with some incident. This isn't the case. Richard is more than capable of getting the cars down the track.

It may have had something to do with some of the reasons I posted above or the fact that Richard actually WASN'T the only car with Chute problems this weekend. There are alot of variables that come into play when going into uncharted territory. IMO if there is any place to test a chute on a new platform it would be at a place like the mile where there is plenty of run off in every direction.

 

One small note: The accident itself was pretty horrific to see. After it happened I know the guys I was with didn't seem to think he stood a chance. I really can't describe what happened, it was violent. There is a video from a guy who was standing near us at the finish line that i'm sure will pop up on the net eventually. It really is a miracle Richard walked away from this and a true testament to what a terrific job Underground did in building a GREAT cage. Going these speeds is no joke. The Texas Mile slogan is "You have no friends at 200mph" it certainly seems that way after this weekend.

 

Thank you for the response.

I'm glad someone else is on the same field I am on.

To the parachute mounting spot, I really hope UGR is smart enough to know where to put those. With their drag racing experience and all. Not a poke at you StreetRod, don't get uppity!

As much as I have distaste for Hennessey, I actually agree with what he said. A lot of these guys should also switch to the CO2 deployed shoots instead the typical kind. I don't know if that's Bonneville spec or not.