metal hood scoops

[Harold Bettes]

Hey Fellas,

Does anybody have a suggestion or a site for metal hood scoops like a L88 style or something similar that can be added to a steel hood? Don't want to go with a flimsy fiberglass hood.

Thanks in advance.

Regards,
HB2

[JackD]

I guess I don't understand why a glass hood has to be flimsy or why an attached part has to be the same material for starters.

[Bob Drury]

Harold, a L88 type scoop is nearly worthless unless you just need it for clearance.  The laminar flow that close to the hood is not good at the point of entry.  You need to have your intake closer to the 12" limit (top of scoop) if you want the best air.  Once again, I recomend picking up the July 2007 issue of Circle Track magaxine and reading the aero article.

[Sumner]

Harold don't know if any of this will help or not.

     

John (WZJUNK on here) made the scoop on the front of Hooley's Stude.  I sized the opening using the formulas you can find here:

http://purplesagetradingpost.com/sumner/bvillecar/bville-spreadsheet-index.html



At the same time he built the scoop he made the front all one piece.     

   

Here you can see how he at the same time reinforced it with additional ribs. 



Finished and ready for final paint.  John did a very good job on this.  He thinks it is about the ugliest thing he has ever done, by I think it is cool and it has worked very well. 

There are more pictures of him building it here:

 http://purplesagetradingpost.com/sumner/hooley/hooley-construction-2005-1.html

Bob is right about trying to get the opening up into clean air.  Bob do you know if they sell back issues of that magazine??

c ya,

Sum   

[RidgeRunner]

Sum,

     Try circletrack.com.   "This month" .   "General tech" on left of screen.   "Downforce"  explained article.  Think you might find it interesting reading.

                                                                                                                                                                                             Ed

[Sumner]

Sum,

     Try circletrack.com.   "This month" .   "General tech" on left of screen.   "Downforce"  explained article.  Think you might find it interesting reading.

                                                                                                                                                                                             Ed

Thanks. 

I read it and I'll probably regret saying this, but "I feel" one should be very careful in taking circle track aero information and applying it to land speed racing.  They are trying to ride a thin edge of good aero to make the car faster and at the same time trying to create downforce to make the the car "stick" in the turns.

Aero downforce usually comes at the expense of drag.  They are creating a low pressure area at the wheel openings to try and suck air out of the front and back of the car for increased down force.  Creating those low pressure areas probably results in turbulence there which will create aero drag.

Rightly so they want to keep the car as light as possible or the rules permit to help with acceleration off the turns.  So if they can get the downforce they need through aero and not added weight they will probably go for it at the cost of maybe a little top end speed.  We are trying to gain every last mph we can on the top end and will give up a little acceleration to gain that.  So in our case we can use weight for the downforce we need for traction.  I think at say 250 mph the hp needed to haul more weight is minor compared to the hp to get through the air so I'm looking to get the car as aero as possible even if it comes at the expense of some downforce.

Just my thoughts,

Sum

[JackD]

" Don't date out of your species."
"A Daytona car will fly on the Salt and a Salt car will fly at Daytona, and I don't mean go fast." (me)

[Bob Drury]

Sum, I am not even sure if that issue is on the newstands yet.  As far as roundyround vs lsr in the use of aero, What I was trying to promote is the general aero concept.  Obviously the air they run in is nothing like ours, but the principals remain the same.  I just like the fact that most of their articles can be understood by burnt out hippies like me.  Every time I try to read technical articles, rule books, or directions of any kind, I suddenly become dyslexic.  Jack should understand............

[Sumner]

Sum, I am not even sure if that issue is on the newstands yet.  As far as roundyround vs lsr in the use of aero, What I was trying to promote is the general aero concept.  Obviously the air they run in is nothing like ours, but the principals remain the same.  I just like the fact that most of their articles can be understood by burnt out hippies like me.  Every time I try to read technical articles, rule books, or directions of any kind, I suddenly become dyslexic.  Jack should understand............

Let me back up a little  ,  I thought it was a good article and explained how to generate downforce on the front and rear very well in a way I wasn't aware of before.  I learned something new  .  Like you I'll try to learn anything I can about aero regardless of the type of racing it is pertaining to as you never know when you might be able to use some of what you have learned.

What I was trying to caution against is that what the circle track guys are trying to do with aero is "sometimes" counter to what we are trying to do.

A "burnt out Hippie"   We will have to compare beard and hair length (not quantity  ) on the salt ,

Sum

[Dynoroom]

Hi Harold, having run 2 different cars (and set records with both) w/cowl hoods I understand what you are looking for, easy way to get started running your car as you develop your package. I remember seeing a steel cowl scoop somewhere, I'll try to source it and let you know  (Goodmark has some). But you can run a glass hood with no troubles, just lots of Dzus fastners or hood pins.

Talk to you soon.