Intercooler Ducting:
Just like the radiator, proper airflow to the charge cooler is important. Because the car is running on methanol, the charge cooler core is sized much smaller than a normal core for 1400hp. The core is also a PWR unit which was optimized for the flow path. The smaller core size allowed us to feed it with air via a shallow duct on the decklid. The decklid has almost no effect on the rest of the flow rearward. The outlet of the intercooler just dumps into the engine bay and is evacuated out the opening in the rear of the car between the bodywork and floor.
Body Work:
The bodywork was also done by us with conceptual help from Oilstain Labs. The original concept of the car was from Scarbo Performance which was a rear-engine setup that was rendered by Oilstain Labs. Oilstain was critical to working with to help keep the proper 911 look, especially on the front bumper and hood/fenders. I kept wanting to make the front end more aerodynamic and they kept bringing it back to reality looking like a 911. I think we ended up with a nice medium ground of performance and looks. The turning vane on the front bumper was a nice addition to the performance by helping flow to the winglets and promoting outwash.
The hood/fenders are pretty much a 911 but wider based on the Oilstain concept. We added gurney/wickers in front of the outlet duct to help with the evacuation. We also added gurney/wicker in front of the fender vent to help with evacuation out the wheel well. These help with making front downforce by evacuating air from the diffuser in the fender well and winglets.
The decklid has a built-in duct for the charge cooler which was already discussed. It also has a built-in ducktail to help with downforce creation and support the airflow under the wing.
We would like to thank Paul Lucas, Verus Engineering, and BBi Autosport for this exclusive in-depth look at the aero of this groundbreaking machine. As a quick update, I am going to be flying out to Colorado to help dial in the car’s suspension and if I am allowed to and have the time, I will have more details on the insides of this marvelous machine soon!
9 comments
Thank you for this one! Fantastic article.
Thanks for sharing this Mike, and thank you to Paul/Verus for detailing elements of the aero development.
I hope all involved in the project have a great time at Pikes Peak!
Unfortunately, things didn’t go very well.
This is such an awesome article, written in a way to make something very complex fairly easy to understand for someone with a limited understanding of aerodynamics such as myself.
Are there any rules against moveable aero? Seems like this would be a perfect application of sliding side skirts and possibly even fan driven suction for low speed downforce.
Stuff like that would get destroyed on the mountain.
So sad that this didn’t get to make a run due to the engine failure. Hopefully they do some real shakedowns before next year’s race.
How effective are the NACA ducts at cooling the engine/gearbox? Does it affect the pressure flow under the car thru the diffuser?
Pretty effective, but more testing is still needed. No real change to the diffuser based on before and after CFD runs.