We have developed a front splitter for the E90/E92 M3 chassis. This splitter has been tested at Road America and develops a significant amount of downforce-so much so that we would not recommend this splitter without balancing out the rear end with a wing. Anything over 100mph and the car became rather unstable in the rear under brakes. Our test E90 M3 had a full interior and no weight savings whatsoever, so we would assume that a lightened car would have even greater issues without a wing.
We were also surprised to see similar cornering speeds through the long right-hand sweeper (carousel) at Road America on 340 treadwear continental street tires with the splitter as compared to our Pirelli DH slicks we ran without the splitter.
Our design and install procedure creates a slight downward rake (towards the front of the car). The leading edge of the splitter mimics that of an inverted airplane wing, transitioning the airflow smoothly under the car.
*This splitter also includes the undertray and makes the underside of the car completely smooth all the way back to the aluminum belly pan reinforcement plate-this is the large pan that has cutouts for your oil drain plugs.
We eliminated the rectangular cutout for the center primary oil cooler. Instead of exhausting the air downward into the smooth flow coming from the front of the splitter, we allow the air to travel over the top of the splitter underneath the engine and exhaust the air on either side of the undertray near where it mounts to the reinforcement plate. We believe that doing it this way increases the effectiveness of the splitter while reducing drag and still providing full cooling efficiency of the primary oil cooler. When track testing this setup we only saw oil temps rise to 235F. On a warmer day with the stock setup, track oil temps were around 250F. Thus, we believe this setup does not adversely affect engine cooling.
To further back these claims, our top speeds were basically identical with and without the splitter.
How it's made:
We make all of our parts out of carbon fiber, we do not use fiberglass. Splitters can be specified in either 3K plain weaves or 6k 2x2 twill weaves. There is also an option to add Kevlar on the bottom side of the splitter to aid durability during ground/curb contact.
We use a vacuum resin infusion process along with a wet layup vacuum process to make various splitters/undertrays, etc.
Splitters can be made to any thickness, generally ranging from about 0.25" to 1". Thicker splitters are required in racing applications if high downforce is present. In order to increase the strength of the splitter where necessary, we will add a structural foam core to the composite sandwich structure. The core will not be seen but added for strength. Structural foam is very lightweight, very strong, and highly resistant to compression.
For reference, our E9X M3 splitter/undertray combo can support 200+lbs at its center while weighing in at roughly 6 lbs.
A thicker, stronger splitter can also be used in street applications for appearance and also reduces the number of mounting locations required to install the splitter. In most street applications, a splitter in the 0.25" thickness region will suffice.
We do not currently offer clear coating but are working through solutions to offer this service. You can apply any automotive clear coat of your choice.
Pricing starts at $400
Call us for recommendations: 414-212-5679