How can I put this?

G

gsbaker

New member
I hesitate to post this because it smacks of blatant commercialism, but there is a method to my madness. If Bill (the moderator) chooses to send me into the electronic darkness, I probably deserve it--and apologize in advance.

We received an e-mail recently from a customer regarding a crash he had while using our product. Customers who post to the IT board have crashed, but I would like to know if their experiences were similar, i.e. how the system "feels" during an impact. We are simply attempting to confirm a theory. We could do this via phone/e-mail, but I felt some public cross-pollination might be valuable.

Crash dummies can't talk about how the system feels. Our best guess it that it should be relatively transparent--the force of the impact pulls the head one way, while the damper reaction pulls the head the other way. The force holding the head should be felt within the helmet, but the net force on the upper neck should be very low.

It would be best to get feedback from a very experienced professional driver, equipped with a data recording system, who had a slight impact that allowed him to notice how the ISAAC system functioned. We got that this week.

Ironically, the driver was my school instructor, Mick Robinson. There is a link to his Web site on our Racers' Comments page if you want the details. After my school Mick had two comments: 1) "I would like to try that shock restraint," and 2) "You are a really bad driver" (I'm paraphrasing--he was very diplomatic).

His e-mail is below, less a section dealing with sending the system back for evaluation, etc. My question for you headbangers is, Does this sound familiar?

Hello Gregg:
I have had some time to go over the data from my Sebring accident.

I was hit on the left front by the other car with a force of 1.56 G's from the side.

My car immediately headed right. The carousel at Sebring has the outside [tire] wall following the curve of the track. When I got hit, the car darted right so that I hit the wall at about a 60 degree angle. The speed on impact was 62 mph. The data shows 3.2 G's on the wall impact.

I immediately felt the ISAAC work on the frontal impact, but I did not notice anything on the left front hit.

The comfort of the impact still baffles me. I have hit several walls with an almost straight on impact and have had sore muscles immediately after and the days that followed. I have on one occasion felt an electrical shock go down the spinal cord on a similar accident at Daytona when I hit a car at a 90 degree angle at 98 mph. I have had the internal part of my throat swell for 2 days after one impact also.

After this incident, there was no muscle soreness at all. I did not have any soreness the following days either.

I feel so confident in the system, that I recommend that you sit in a sled and go through a 3.2 impact to see how well the device works. Seriously, there was nothing too it.

I don't think the shocks traveled to their maximum distance as the deceleration was gradual and very comfortable. My forehead did not feel as though it supported all of the force from the slowing down of my head. It was strange, but the whole force of the impact was absorbed by my whole head. I felt as though the cheeks, forehead, temples and lower rear of my skull equally felt the force of the deceleration. I'm not a test dummy with probes all over me, but that is the way it felt. Kinda like my head was wrapped in bubble paper. When the fluid traveled in the shocks, it felt like my head was in a cushion of air. I just didn't feel any violent movement from the wreck....

Thanks for working on a restraint device for racers. You have saved me a lot of pain from the wreck that I went through at Sebring.
Click to expand...

This was a mild hit--nothing but a big tap really--but enough to invoke a damper reaction. A rough estimate suggests that he experienced a head load of nearly 100# if he were unprotected. That won't kill you of course, but it's still a nasty little yank.

Given that there is not a snowball's chance on a Florida beach that I will ever strap myself into a crash sled, I would like to know if any of this is familiar to those of you who have had a crunch.

Thanks.

[Edit: Proper formatting is appreciated by all]

------------------
Gregg Baker, P.E.
Isaac, LLC
http://www.isaacdirect.com

[This message has been edited by gsbaker (edited January 21, 2004).]
 
No, this is not a "shameless" plug....No not at all.........It's the kind of reminder we need to make ourselves, as racers, safer and able to continue to enjoy the hobby that we love so much.......thank you for sharing.

------------------
Phil Phillips
94 Acura Integra GSR #4
ITS/H3/ST1
www.philstireservice.com
Amsoil Dealer
distributor for FireCharger AFFF fire systems
Hoosier Tire Dealer
Toyo Tire Dealer
 
Why don't you offer (maybe only for their first crash) a free checkup of their ISAAC system? It gives drivers a strong incentive to ship you their system (safety bonus), and it means you get their stories...

Along the same lines, I was wondering (I'm obviously not familiar with the precise characteristics): If the construction of the system permits it, couldn't you put some sort of rubber O-ring on the piston shaft (preferably inside the casing) which acts as a marker, telling you the deflection the system underwent during the crash? From there on, a simple calculation will tell you the G's that the driver hit.

I hope I'm being clear; it's somewhat difficult to phrase, but what I'm envisioning would be a good (cheap) way to incorporate a measurement of deflection into the system, with a simple sliding rubber oring... Obviously, it assumes that either the system undergoes a deflection unatainable in normal conditions, and/or that the system is not tinkered with after the crash.

What do you think?

Alex
[email protected]

[This message has been edited by Alex (edited January 25, 2004).]
 
2.5G's is nothing...I'll volunteer for the sled for a free ISAAC
wink.gif
 
after watching some WRC yesterday, I wondered what those teams use? It would be incredible publicity if you could get your product into one of those cars
 
Hey Gregg,

Congratulations. I just saw Andy Wallace wearing an Isaac restraint in the Rolex 24 Hours of Daytona!


------------------
George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com
 
Originally posted by Geo:
Hey Gregg,

Congratulations. I just saw Andy Wallace wearing an Isaac restraint in the Rolex 24 Hours of Daytona!
Click to expand...

Looks like the whole team is wearing them (makes sense). They just showed Tony Stewart with his QR straps on.




------------------
George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com
 
Alex,

What you are proposing would work if the cylinders contained a spring, so you could tell how much load they were exposed to. But you can easily extend a shock all the way, if you do it slowly.


Geo,

The team may have been using Isaac systems, but my best guess is that you saw a Hutchens device. We don't use a QR buckle with a strap, we use a QR pin with a small cable tether. Also, we do not have Wallace and Stewart listed as customers, but lately we have noticed some prep shops ordering multiple Isaac systems on behalf of customers.

Last summer Stewart switched from the Hutchens to the HANS, but the word is that he did not like it at all, so he has probably dumped the HANS and gone back to the Hutchens.

------------------
Gregg Baker, P.E.
Isaac, LLC
http://www.isaacdirect.com
 
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