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Bonneville 2019 prep, and a request for help.

 
Old 07-15-2019, 03:57 PM
  #16  
Harvey928
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Carl,

I would have loved to be there with you and the team. I traded my 2012 tundra in on a 2019 VW Tiguan. It can only tow 1500 lbs. I wish you and the team all the best, and even more prayers and love to your wife.

Harvey
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Old 07-15-2019, 06:09 PM
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Carl Fausett
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On a flat tow, the straight pull on this car is about 400 pounds. No problem! Come on down! In 2012 Steve brought one of his kids Quads and that pulled it around in the pits. Was a little much for the little Quad, but it worked. Your SUV would have no problem.
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Old 07-15-2019, 06:31 PM
  #18  
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Today we put up the belly pans with their ballast. The driver's side weighs about 500 lbs and the passenger side weighs about 650 lbs. Definitely a two-person job! From the side, they will be adjusted so they are higher at the rear than at the front - creating a low-pressure area as the air flow gets to the back of the car to generate some ground-effect downforce. I remember describing how the car would get real squirrely up through 160 MPH, then it would suddenly settle down and squat a bit and get much more civil. He confirmed how much lift he saw in the back of the car up to 165 MPH in the wind tunnel, but that was where the ground-effects started to work and pulled the car down enough to negate the previous lift. Since then, we have made changes to greatly reduce the left we were getting.

The rear diffuser carries the air flow right afterward these belly pans, and they will be installed soon also. Tomorrow I should be hanging the side skirts and setting the ride height. Initial ride height will be 1.5" off the ground, and may be adjusted up or down depending on track conditions when I get there.


A rare pic of the belly pans with just one side in place, so you can see the difference

Here both sides, totaling 1150 pounds, are up. You can see the channel down the center they form for the exhaust and Torque Tube.

Belly pan from the side. This will be adjusted to be higher at the back than the front before the side skirts go on.
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Old 07-15-2019, 07:07 PM
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dr bob
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Carl --

Got side skirts to seal the airflow there next to the ballast pans? Aero under the car from simple stuff like the sloped plate only starts when you can keep air from coming into the side of your cavities. More active aero under the car has ducts that start in the front and exit in the diffusers under the rear bumpers. The vertical strakes in the diffuser are a requirement, and the aero ducts are sealed all the way to the ground on the sides. You would see that in the wind tunnel with traces strings or ribbons at the bottoms of the rocker sills. The wind tunnel results are distorted if the floor isn't moving.

The airflow management under the car, and especially the rear diffuser, isn't something that worth guessing at. It will cause more problems than gains if it isn't done really well. If you start depending on the under-car aero for rear downforce, you'll get a brown-patch surprise if you get at all sideways or see a stiff enough crosswind to disturb the side seal with the ground.
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Old 07-16-2019, 10:47 AM
  #20  
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Pics of the rear diffuser are posted above at post #9 above. Here are the side skirts on the car from 2011. There is even skirting behind the front tire - all that we could do to prevent the incursion of air from under the vehicle.



Here is a picture showing how the side skirts carry around and behind the front tires.


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Last edited by Carl Fausett; 07-18-2019 at 08:16 PM.
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Old 07-17-2019, 10:28 AM
  #21  
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Best of luck Carl. I hope you post some awesome numbers.
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Old 07-17-2019, 05:52 PM
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Here is Myles and I installing our lead-filled tube into place over and slightly behind the rear axle. Each one is about 150 lbs, so 600 pounds in total. The engine hoist allows us to lift two of them at a time and place them (carefully) over the fuel cell and bolt them down. Now that all the ballast is in, I will set the ride height. Coming soon: the alignment, the side skirts, and the front air dam. We leave on August 8th.





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Old 07-18-2019, 08:20 PM
  #23  
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These pictures show the final ride height as-raced. At about 100 MPH, the car will be settled down onto the suspensions stops and another 3/8" of what you see here will be gone.



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