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Anyone have Aero questions?


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1 hour ago, mhr650 said:

 

The ChampCar rules say that the maximum wing height is 12 inches above the roof, but doesn’t say that includes the brackets to mount them.

 

To clarify this, I believe Ray has said that the wing and splitter location rules include the mounting provisions. Make a plane 12" behind the rearmost extent of the car and 12" above the tallest part, and you can't add anything to it that sticks out of that.

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Disclaimer: I have no formal aerodynamics training and most of this info I am going to share I have just picked up on the side for fun. Feel free to critique anything I am about to say.   I

one more before i hit the road.  not quite.  The air being directed over the top of the car does add downforce. It's not the temp to blame, it's the speed. So to make downforce, the general

Put a hole in the top of the fender above your control arm/spindle/whatever. Attach a rod to the top of your control arm that is long enough to protrude above the fender at full droop. Mark the rod at

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On 2/28/2019 at 4:05 PM, LAMR2 said:

 

To clarify this, I believe Ray has said that the wing and splitter location rules include the mounting provisions. Make a plane 12" behind the rearmost extent of the car and 12" above the tallest part, and you can't add anything to it that sticks out of that.

 

How about endplates?

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6 minutes ago, mhr650 said:

How about endplates?

 

On 2/28/2019 at 3:05 PM, LAMR2 said:

To clarify this, I believe Ray has said that the wing and splitter location rules include the mounting provisions. Make a plane 12" behind the rearmost extent of the car and 12" above the tallest part, and you can't add anything to it that sticks out of that.

Endplates fall into the category of “anything”.

 

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On 2/28/2019 at 1:50 PM, zack_280 said:

Should end plates extend beyond the chord (front or back or both)? 

Does endplate shape make a difference?

How much end plate should be above/below the wing?  

 

3 questions 3 answers

 

1. Yes they should. the endplates separate the air like a "plenum"

the common theme is fast-under Slow- over. the high pressure very badly wants to make its way to the low-pressure air to help balance the atmosphere. this is generally how the wind is generated. if your endplates are too short the high pressure on top of the wing will find a way to the bottom when this happens the wing will stall and stop making downforce. the endplates help prevent the air from mixing. so yes make them long, and have them over the entire chord and add a few extra inches for good measure.

2. yes the shape does make a difference. But there is no magic bullet. For our wings we offer CFD Built endplates, that means the computer software was used to shape the endplates. They had a small bump in downforce, But what it helped was efficiency not stalling in a crosswind. On the phone, everyone from the northeast seems to understand that concept personally.  something about the glen. So yes it does matter but you couldn't take our CFD endplate and expect the same result on a competitor's wing.  the shape of the wing plays a major role on the endplates shape. it's a frustration point to us when we hear people endlessly quoting F1's aero designs.  You have a gt car, not even a formula car. stop looking at F1 and get your nose into the current gt3 offerings. know the rules and why some pieces are the way they are. After that your free to gather inspiration.

3. When in doubt go big! you're looking for that plenum effect, a tiny endplate might allow air to bleed over when a large endplate would stop it. Having too large of an endplate almost never means a loss of downforce.   

 

 

 

 

Edited by @NineLivesJohnny
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1 hour ago, cmi11er said:

are dive planes useful in our type of racing?

Front downforce is difficult to get in large quantities.  Dive plains or canards are helpful sometimes. On the gen 4 Camaro's they helped a good bit, but on c7 corvettes, they were just about useless. it all depends on the shape of the car and how the wind flows. 

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55 minutes ago, @NineLivesJohnny said:

Front downforce is difficult to get in large quantities.  Dive plains or canards are helpful sometimes. On the gen 4 Camaro's they helped a good bit, but on c7 corvettes, they were just about useless. it all depends on the shape of the car and how the wind flows. 

Very interesting,   So for a follow up question.  What should be the objective of the canards/ dive planes?   Are you trying to move air out around the car or direct it somehow to not interfere with the air going over the top ?     

 

Thanks again for answering our questions. This is fun stuff. 

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I thought this may help some on airo this is my car Audi tt no spliter or spoiler 

at 40 mph

bebCFQR.jpg?1

the same with a spliter and stock rear spoiler at 40MPH

WbbLZsv.jpg?1

now at 70 MPH with no airo

WUO0JAz.jpg?1

70MPH with airo

xqJ7S8K.jpg?1

100MPH with airo

WKqdsGg.jpg?2

150 MPG with airo

2A12ANz.jpg?1

If you look close the splitter dos more then speed up the air under the car it builds a ball of air in front of the nose to

to push it over the nose giving you more down force on the car . I wish to thank my friend Max Clesca for the pic 

www.DRVOLKS.com 

 

Edited by DRVOLKS
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NB Miata. For various reasons we are not adding a splitter. Rough estimate gain for building up an air dam without splitter?

For an already balanced car, is a rear wing worth adding? Assume we cannot re-balance front grip.

How would you suggest re-balancing front grip in the case of adding a front wing and no front splitter?

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I'm using a performance calculator and need to plug in some values for drag and lift, but I don't know how to figure that out for a wing. I'm wondering how to simulate the 9LR wing at 0-, 5- and 10-degrees AOA. The tool I'm working with doesn't use pounds of drag, and so I'd like to convert this to Cd and Cl based on different wing angles. 

 

So let's take a very simplified Miata with Cd of .40 and Cl of zero, what would be the Cd and Cl with the following? 

9LR 64" wing 0-deg AOA

9LR 64" wing 5-deg AOA

9LR 64" wing 10-deg AOA
 

Thanks, and I appreciate you answering these questions! 

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When testing for initial / baseline setup on a car with a fixed 4-6" long splitter and an adjustable (proper airfoil) wing, which is better / more efficient?

  • Start with minimum angle of attack on wing, increase until driver preferred balance is achieved or lap times start to drop off
  • Start with MAXIMUM angle of attach on wing, decrease until car stops pushing or lap times start to drop off
  • Start in the middle, change to both directions to see which way is faster and continue changing faster direction until lap times drop off
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2 hours ago, NigelStu said:

When testing for initial / baseline setup on a car with a fixed 4-6" long splitter and an adjustable (proper airfoil) wing, which is better / more efficient?

  • Start with minimum angle of attack on wing, increase until driver preferred balance is achieved or lap times start to drop off
  • Start with MAXIMUM angle of attach on wing, decrease until car stops pushing or lap times start to drop off
  • Start in the middle, change to both directions to see which way is faster and continue changing faster direction until lap times drop off

For what its worth, when we started playing with the splitter length vs wing AoA, we started with Min splitter length and 0AoA.  We then added in wing until we added way too much then backed it down in the same steps (1.5deg increments) back to where we liked it.  Then we pulled out more splitter length and decided if the car needed more wing or not and played the back and forth AoA game from that point.

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On 4/4/2019 at 11:12 AM, NigelStu said:

When testing for initial / baseline setup on a car with a fixed 4-6" long splitter and an adjustable (proper airfoil) wing, which is better / more efficient?

  • Start with minimum angle of attack on wing, increase until driver preferred balance is achieved or lap times start to drop off
  • Start with MAXIMUM angle of attach on wing, decrease until car stops pushing or lap times start to drop off
  • Start in the middle, change to both directions to see which way is faster and continue changing faster direction until lap times drop off

in pro racing, we start with minimal aero and increase it. we do it this way because if you start with maximum aero and decrease the driver will bitch and whine. 

 

but we aren't cry-baby pro racers, we say start with max AOA on the wing and slowly take it out until the car stops pushing. 

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Hopefully a simple question, from a areo perspective, ignoring bumper differences and front treatments, what direction is better.

Looking for the lightest way that doesn't trash air.

 

Options: Rear and or side windows

 

This

_DSC3398.jpg&f=1

OR this?

151.jpg

Edited by Team Infiniti
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1 hour ago, Team Infiniti said:

Hopefully a simple question, from a areo perspective, ignoring bumper differences and front treatments, what direction is better.

Looking for the lightest way that doesn't trash air.

 

Options: Rear and or side windows

 

This

_DSC3398.jpg&f=1

OR this?

151.jpg

 

Bed cover and a spoiler definitely.  You are already bastardizing a BMW, don’t half-ass it and stop at the drivetrain

 

EB4F3CA1-5A0D-46CB-9EB3-756AE154F645.jpeg

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Not sure how many we have pts for aero, we have enough repurposed material for the bed cover but that kills the idea for weight savings unless we use the interior leather :(

 

 

Bastard Motor Werks?

Edited by Team Infiniti
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Here is a question, how are people managing spring rates with big aero?  Adding damper pots is off the table for cost reasons.  I have considered some homemade measuring devices but if anyone has a good rule of thumb for Splitter/Air Dam and Big (9libes) rear wing setups on a miata, I am all ears.

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17 hours ago, Alchemy Autosport said:

Here is a question, how are people managing spring rates with big aero?  Adding damper pots is off the table for cost reasons.  I have considered some homemade measuring devices but if anyone has a good rule of thumb for Splitter/Air Dam and Big (9libes) rear wing setups on a miata, I am all ears.

Zip ties on the shock shafts with and without aero.

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