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RE: spoilers

To: "'dferguso@ebmail.gdeb.com'" <dferguso@ebmail.gdeb.com>,
Subject: RE: spoilers
From: "Ferguson, Darrell" <dfergus@bactc.com>
Date: Tue, 9 Nov 1999 18:01:00 -0800
Hi Dan, 
        Glad you to hear you've visited our website, in reference to your
comments regarding the legality of our car, The car is 100% legal per the
1999 SCTA rules for Altered Bodied Vehicles. If you've been a member of the
land speed forum for any time, you'll remember the many discussions
regarding the interpretation of the rules. As a result, I redesigned the
front spoiler for my car (at considerable effort and expense) to be sure
that I would, without any possible doubt, comply with the guidelines set
forth by the SCTA. The rear spoiler on our car, does in fact have one
Aerodynamic surface used to deflect the air for the purpose of spoiling
lift. In an effort to guarantee stability, we decided to make the spoiler
stronger by adding braces to prevent deflection, or failure at high speed. I
hope we have not misinterpreted the SCTA's rule. I was led to believe that
the rules' intent was for 1 surface to be used, not multiple surfaces such
as those on a Top Fuel Dragster. If you are familiar with the NHRA's rule
concerning "multistage elements" they restrict them to 3 separate surfaces,
one behind the other, all at different angles. The NHRA imposed this
restriction when someone discovered that 2 separate surfaces generated more
downforce than one. As a result, everyone started running 2 elements on the
rear of the car. Then someone said, if two work better than one, three
should work better than two, again more downforce was realized, with minimal
increases in drag. Soon the race was on with 4 and 5 element designs being
deployed. Unfortunately, the increased downforce caused strut failures that
would subsequently send the car out of control (now- no downforce with
broken struts!). Finally the NHRA stepped in to limit the # of surfaces to
3. Along those lines, the SCTA has restricted racers in the Altered Class to
only 1 surface, which my rear spoiler has and, I agree with the SCTA that
multiple surfaces would allow spoiler designs to generate downforce at
unsafe levels. My brother and I spent considerable time designing our rear
spoiler to comply with the SCTA rules, making sure the spoiler did not
exceed the measurements called for in the rulebook. I actually spent
considerable time with an SCTA inspector, and a few altered class
competitors, including Alan Fogliadini earlier this year at El Mirage
discussing the legality of my car. I showed the inspector pictures of the
car, and recited the rules regarding spoiler design and aerodynamic device
classification from memory since I had reviewed the rules so often to make
sure my car would be legal. He checked the 1999 rule book and agreed that
the spoiler was in fact legal per class rules. While I cannot remember his
name, he races the # 304 BBGALT Camaro, and in my opinion, I would expect an
SCTA inspector to be critical about a different design, albeit legal,
especially since he races in almost the exact same class as I do. When he
gave his blessings, I assumed it as law.
         In reference to the plates behind the car, we were unclear in the
rules as to how the two plates would be classified. We refer to them as
"chines" since there is no classification for any device within the
paragraph outlining Aerodynamic devices that is even remotely close to our
rear chines. We designed them with the intent of helping to keep the car
pointed straight should we begin to go sideways at high speed. Also it will
help prevent salt spray from corroding the parachute, mount, and cords.
Other than that, there is no aerodynamic benefit of the two plates. Since we
did not know how the SCTA inspectors would receive this new chine, and did
not want to make the car illegal for competition in the altered class, we
designed them so should the SCTA deem the chines, or plates illegal, then we
would simply remove the 20 bolts that hold them on, and return to legal
status. Again, this goes back to interpretation of the rules, and although
we feel this will only make the car safer, we designed the two lower plates
with that question in mind. 
        Since I started subscribing to this list, the topic of rule
interpretation has come up frequently. I have heard comments ranging across
the board. The most common have been that since my car is nowhere near as
aerodynamic as a new thunderbird, or a 1990 Firebird, I will not be judged
as harshly. I am obviously at a disadvantage to begin with using a 1968
Firebird body for competition within a class dominated by vehicles more
aerodynamic than mine. I've also been told that the faster I run, the more I
will be scrutinized. While it is tough to interpret and enforce the rules
for the wide variety of bodystyles, for me the rules should be a bit more
consistent throughout the class. I designed the two plates for high speed
stability. With my knowledge of aerodynamics and fluid flow from college,
the two plates, if anything, are a disadvantage while the car is traveling
straight, and aerodynamically buy me nothing. Should the car start to spin
however, the idea is to help the car from coming around until I can slow to
a safe speed, much like fins on a dart keep it pointed straight. If the two
plates are classified by the SCTA as diffusers, and subsequently illegal for
the Altered class, I will remove them. I am in total agreement with you Dan,
I would be disappointed to have gone to such great lengths to keep the car
within the Altered Class rules to be violated for a safety improvement. This
is why we made them removable.
        I would like to say thank you for your concern about our project.
And your foresight to address topics similar to these at the upcoming rules
meeting. I know that I, as will many others on this list, look forward to
your reply.

        Sincerely

                Darrell Ferguson
                BLACK RADON ENGINEERING
                # 939 BBFALT
                http://my.cybersoup.com/blackradon          




> -----Original Message-----
> From: Daniel Warner <dwarner@electrorent.com>
> To: Land Speed <land-speed@autox.team.net>
> Cc: Dan Warner <dwarner@electrorent.com>
> Date: Tuesday, November 02, 1999 6:18 AM
> Subject: spoilers
> 
> Darrell,
> Just visted your page to look at your project. Appears to be a fine piece
> of craftsmanship, a vehicle to be proud of.
> I am curious though as to your interpretation of the rear spoiler. As
> referenced in your text a non-stock spoiler may be fabricated to the specs
> called out in section IV-24h (misprint, should be IV-26h). The spoiler on
> your car doesn't seem to meet the single aerodynamic surface rule. I also
> reference page 53, last paragraph, 1st sentence "No streamlining allowed."
> What caught my attention was the plates under the rear of the body which
> look like diffusers(?). Please look at page 38, IV-26 Streamlining. The
> opening paragraph defines SOME types of streamlining devices.
> The intent of "No streamlining" and the section defining streamlining
> devices is to point out that if the class is not allowed streamlining
> anything under section IV-16 or appears to be non-stock for the class is
> not allowed.
> With the approaching date for the rules meetings I would like to be sure
> that we are clear with the wording. It is difficult to present rules to
> the
> competitors who are out of the So Cal area. Locally we can communicate
> with
> each other directly concerning applications of the rules. We certainly
> don't want someone building a car/bike and travelling several thousands of
> miles to be out of class. It is not our intention to stop an entry from
> running.
> Dan Warner
> 
> 
>  

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