Modification to rear spoiler for Altered & competion Coupes classes

[bvillercr]

JL222 Hi, as I mentioned in earlier post, in 2009 when I was one of the course timers (for Frank Scott) for the three race courses at Speed Week we had a near crash with a late model Corvette on the long course, at the 4 1/2 mile point at over 200mph he went into a spin, the video of this spin showed that when we went backwards the rear spoiler lifted the rear wheels off the ground about 2 ft, the front wheels were still on the salt, but then with the force of lifting the rear of the car off the ground broke the rear spoiler off the car, which let the rear wheels of the Corvette come back down on the salt, thus not causing the car to crash. Then the car with no spoiler continued the flat spin with no damage to car except, broken rear spoiler.  This is only one example, I'm sure not all spins or crashes are caused by rear spoilers, just want to see if we can eliminate some crashes with a new rule change. I do like the ideas others have mentioned on this web site,  Thanks Dave

  The spoiler falling off makes my point about amateur builders.

             JL222

He was incorrect when he spoke about a spoiler, it didn't have one.  The deck lid blew off.

[Avanti Kid]

Bvillercr, I stand corrected, I thought it was a spoiler that came off the Corvette in 2009, but it probably was the rear deck that come off, then the car dropped back down on the salt to continue the spin, but did not crash.  Maybe I had a Senior moment (71 yrs old) 
  Thanks for the update, Dave

[jl222]

I've been Land Speed racing for 17 years and have raced my 1963 Avanti at El Mirage, Muroc and Bonneville.  I've been on the SCTA rules committee for Coupe & Sedans for 10 years. I came up with a suggestion concerning safety for race cars that have rear spoilers (ALt & CC classes) that have over the years caused crashes on cars that spin out at above 200 mph.  I'm in the process of requesting a rules change for the SCTA board to look at in late 2011. I entered this suggestion this year but was 3 days late on the dead line for submitals to the rules changes for 2011.  My suggestion is for non- production rear spoilers to be designed such that when the race car is going forward the spoiler provides the down force required for traction for the car, but incase of a spin and going backwards at over 200 mph, the spoiler would have a folcum that would allow it to lift up and release any lifting pressure on the car, this would stablize the car by not allowing it to be lifted up in the air and flip.  Last year (2009) I was doing the timing on the Short course and Special courses for Speed Week and from a video we saw, it showed a Corvette spining and going backwards, the rear spoiler lifted the two rear tires off the salt, the front tires were still on the ground, the rear of the car was up about 2 ft when the rear spoiler came off the car, which caused the rear wheels to make contact with the salt again, thus avoiding a crash!  Its a simple engineering fact that a spoiler gives you down force when going forward and lift when going backwards. So I'm requesting that when racers make their own rear spoilers they include a piviot point (folcum) to allow the air to spill out when going backwards,  I hope this idea get approved for 2012. I would appreciate comments from other racers, especially those in the Altered Coupes and Competion Coupe classe to look at this concept and indicate if they think its a good idea or not.  I interested in Pros & Cons on this concept so please give me your honest opinion, let me know if you have any questions on this subject.
  Thanks, Dave Bloomberg (Avanti Kid Racing)

  Dave its still not a bad idea, even if the above didn't happen as you thought you saw, but more research is needed on the forces and loads and if it would make a difference before making a rule. I hope everyone can see my point now about having a video to watch.


                        JL222

 

[Avanti Kid]

JL222 I agree with you 100% we don't need another rule in the thick SCTA Rule book that does not benefit the racer, yes, we need some analysis engineering to see if this is practical!  I certainly don't want to push thru the SCTA rules process a concept that hurts racers or makes no sense. Especially because my car (Gas Coupe) is not allowed a rear spoiler, but you and others do use rear spoilers, so I think the best ideas for better safety should come from you folks in those racing classes that can use rear spoilers. Question? has anyone ever tried to make a rear spoiler with a pivot point or with flaps??? Could someone try this  concept with strain gauges to read the loads on the spoiler at high speeds??  That would give us some engineering data, didn't someone earlier on this thread say they did testing in a wind tunnel with a car model going forward and then backward??  Thanks Dave

[Hooley]

I talked with Sum early this week. He was headed north from Fla to his sisters.  He sain it was cold in Fla. too.    Hooley

[DSR88]

http://s1027.photobucket.com/albums/y335/DSR-88/ Here are a few pics. The spoiler was originally flat. Something to look at.
- Donnie

[DSR88]

Be sure zoom in on each Picture.

[jl222]

Be sure zoom in on each Picture.

  Donnie... I can enlarge the foto a little but can't zoom in so i'm not sure,but did the spoiler fold downward?
  Also it looks like there were no endplates above our below the spoiler.
  Can you give us more details on what caused the crash and afterwards
  Sorry that happened to you guys, is the car a total.
  Your dad and the Banks firebird were the inspiration for us to build the 222 car.


                 JL222

[DSR88]

for those interested in the causes of 2010 crash of Stringfellow & Kirk Comp-Coupe & our planed changes to the NEW car here it is.
In 2009  we had runs over 250 with front & rear load cells recording downforce increasing with speed.  2010 recordings showed
what changed & led to crash. 
At 2 3/4 mile lost freeze plug, block pressure went to -0-.  47 gallons of water from rear & passenger side tanks emptied into bellypan
& drained under car @ bell housing area.  As speed went up ,front down force went up & rear never  came up?
( water spray under car + rear weight & down force going away + 270MPH = )
  At 4 1/4 mile car turned right in a blink.
  We have crash sequence pics. 1 set of 13 & 1 set of 30, showing car turned about 60 degrees with rear already flying ( flat spoiler bowed up trying to rip trunk off car).
The new car will have spoiler  hinged & current rules legal. 
 

[DSR88]

Look at the pick of the whole car and zoom on that one. You can see the air bowing the spoiler up lifting the car. Your right we did not take full advantage of the rules on the spill plates. Yes we are rebuilding the car go to kirksautomotiveinc.com take a look.

[jl222]

  Donnie... not sure you read my post as you replied within a min of mine

                 JL222

[DSR88]

Yea yours came up as I posted what led up to the crash.

[Peter Jack]

What a great example of a well designed and built car. The main damage is to both ends where the energy was absorbed and the center area where the driver is is intact  That's exactly what should happen in the event of an "incident". Congratulations on a really good build.

Pete

[DSR88]

Thanks , now we just have to finsh rebuilding it and make sure that don't happen again .

[Avanti Kid]

Donnie, thanks for your honest assessment of what happened to your car!!  Losing the engine's water really caused the crash as the rear tires lost traction (going over water) and your weight balance traction changed on car to cause the event.  But as you show in the photos the rear wing did lift the rear of the car off the ground for a crash, so from your experience and your new build for your car, and you building hinged rear spoiler sounds like a good idea, In the SCTA rule book it calls out a rear spoiler design #1 and a spoiler design #2, Question would it be a good idea to make my rule request ask for a spoiler design #3 which would have the feature of a hinged rear spoiler??  This way we would not force some of the racers to fab a rear spoiler that's not to their liking, but others could have permission to build the #3 spoiler if they wished to and it would be legal for inspection purposes. Let me know if this is the direction we should go for a rule change.  Again, please give me your opinions Pros and Cons are welcome,  thanks Dave