Description
Professional Awesome High Downforce Splitter Diffusers
- Designed and optimized using Computational Fluid Dynamics (CFD) to ensure predictable aerodynamic efficiency.
- Once installed, these diffusers create a low-pressure transition zone that increases the downforce potential of a flat splitter.
- Engineered for installation on an otherwise flat splitter to convert it into a functional front aerodynamic element.
- Pair these units with our universal vents to maximize total downforce gains.
- Engineered and manufactured in the USA from durable, high-quality ABS plastic.
- Each purchase includes two diffusers (one left and one right).
- Physical dimensions are 2.25″ high on the short side and 4.5″ high on the tall side.
- Utilized on the record-breaking Professional Awesome Time Attack Mitsubishi Evolution.
Installation Notes
Ensure adequate clearance both in front of and behind the diffusers so airflow is not constricted, allowing for proper performance. These units can be riveted, bolted, or bonded to your splitter platform.
Chassis Mounting Warning: These diffusers generate significant front downforce. Ensure your splitter is securely attached to the vehicle chassis; inadequate mounting can result in the assembly separating from the vehicle at speed.
Manufacturing Dynamics: Due to the large draw required during the vacuum-forming process, the flange thickness varies from front to rear. When routing an inlay, builders should expect a slight step at the leading or trailing edge. This variance does not affect aerodynamic performance.
Printable Template: Professional Awesome Racing Large Diffuser Template
Technical Resources
For detailed documentation on building front splitters, diffusers, flat bottoms, or wings, view our guide: DIY Downforce – Design and Optimization.
To determine aerodynamic balance and component compatibility, read our analysis: Matching Front Diffusers with Rear Wings.
Customer Examples
Dan Foley (verified owner) –
These diffusers are HUGE! Very easy to install and since they are cfd designed I know they make a bunch of downforce. The information that Professional Awesome provides makes it very easy to balance the aero on any car
Brian Van Orsdol (verified owner) –
Extremely poor quality vacuum forming. Thickness ranges from 5/16” at the front to almost paper thin in the rear. Makes it extremely difficult to route in. Performance was acceptable, but fit and finish was terrible for a piece of HPDE/other cheap vacuum formed material at the price point.
Daniel O’Donnell –
Brian,
Thank you for taking the time to leave this detailed review and for supporting Professional Awesome. We completely understand your frustration regarding the installation process, and you bring up a very valid point about the flange thickness.
To give you and future customers some transparency into the manufacturing of these diffusers, the variance in thickness is an inherent byproduct of the vacuum forming process. Because of the sheer size and depth of the draw required to shape these large diffusers, the material naturally stretches as it is pulled down into the mold. This is exactly why you experienced the 5/16” thickness at the front tapering down toward the rear.
We absolutely recognize that this makes plunge routing an exact inlay difficult. As you discovered, it forces a compromise where either the leading edge sits slightly taller than the surrounding splitter, or the trailing edge sits slightly lower.
We heavily weighed our manufacturing options during the development of this product. Achieving a perfectly uniform flange would require switching to injection molding—which carries astronomical tooling and mold costs for a part of this footprint—or moving to large-scale, high-precision 3D printing. Both of those routes would have dramatically increased the retail price, moving it out of the accessible range for many in the grassroots and time attack communities.
Our ultimate goal with this product was to deliver the highest degree of aerodynamic performance possible at a reasonable price point. While the flange thickness isn’t completely uniform, both our CFD data and track testing show that the aerodynamic difference between a perfectly flush inlay and one with a slight step is completely imperceptible. We are thrilled to hear that the performance on track met your expectations, as functionality is always our absolute highest priority.
That being said, your feedback is incredibly valuable, and you are entirely right that this should be acknowledged. Because of your review, we are updating the product description on our website to explicitly note the variance in flange thickness due to the vacuum forming process, so future builders can plan their installations accordingly.
Thank you again for your honest feedback. It helps us improve, and we appreciate you trusting us with your aero program.