"These build journal entries are part of a special series covering BMW M's most popular wing designs. Written in collaboration with Silvano at CarbonProduction GmbH, I take you into the historical development of these wings all the way to my unboxing impressions of the GTS, GT4 and M235/240i Racing wings.
In this journal entry, I take a tour down history lane and provide more insights to BMW M's aero development starting with the E92 M3 GTS. A lot has been learned over the years."
The Ancestor: the E92 M3 GT4, sort of.
The E92 M3 GT4 was initially introduced without a wing as BMW still hadn't released the M3 GTS. They had already planned on offering the E9X M3 GTS 122cm carbon wing for the GT4 customer race car.
From the street to the track: wrong way.
The stock body E92 M3 wasn't exactly an aerodynamically efficient body. The pre-2007 era of street car aero development was limited to wings and smoothened underbodies.
The GTS aero package of its lowered right height, extended lower splitter and trunk wing worked together to eliminate lift experienced with the OEM aero body.
The GTS front lip and adjustable, chassis mounted lower splitter.
The GTS rear wing carbon board was 122cm in width.
BMW M provided it in satin black finish.
It had low mounts that were adjustable for angle of attack.
It eliminated lift.
The GTS wing provided a +53 kg delta at the rear over the stock body in combination with the front GTS chassis mounted 5 piece lip.
It wasn't enough.
"A rule of thumb in aero: the front always works in tandem with the rear."
The GT4 Customer Racing cars were fitted with the Genuine BMW Motorsport GT4 lip.
It extends further outwards than the GTS lip. The GTS wing board proved too small for motorsport use. BMW M had to rapidly revised its design.
The GT4 lip was designed with additional mounting points to the bumper in order to support the aero load.
The GT4 MK1: it still wasn't enough.
BMW M attempted to solve this problem by introducing the MK1 GT4 wing.
It came with a wider carbon wing board of 130cm but retained the standard GTS mounts.
It still wasn't enough.
There were supposedly still complaints about rear end lift.
Here's Peter running the MK1 GT4 wing at full Angle of Attack.
The GT4 Mk2:
Higher and wider did the trick.
They introduced the E9X M3 GT4 MK2 carbon wing board of 140cm and extended risers.
It proved better suited for the circuit and provided superior stability compared to the GTS.
The wider board extended beyond the body.
The wing board retained the same end plate design.
The MK2 GT4 risers extended beyond the dimensions restricted by street legislations. This was purely a Motorsport product.
The differences between high and low mounts. These are the lightened versions by Silvano.
The F8x M evolutions.
The M235iR Customer Racing Car.
BMW introduced the M235iR in 2014: it was designed to fill a gap in BMW's customer racing program as an entry-level racing car after the end of production of the E92 M3 GT4 and prior to the release of the F8X M4 GT3, GT4 and M2 CS Racing car.
The M235iR was used in series and events such as the VLN Endurance Championship and the Nürburgring 24 Hours on the Nürburgring.
For reference, the M235iR started at 59,000 euros whereas the E92 M3 GT3 started at 121,000 euros.
The car was the usual BMW Motorsport recipe: stripped out interior with bucket seats, roll cage, safety gear, improved suspension, brakes, wheels & tires, racing electronics (ABS, DSC, TC) and limited-slip differential.
What was out of the norm for its modern entry level racing cars was the introduction of a revised widebody design and aerodynamics.
The EVO WING.
BMW Motorsport visibly learned from the E92 M3 GT4 Customer Racing Program and introduced the M235i Racing Car with the EVO aero package from the start.
The learnings of a wider wing board using high risers were carried over from the MK2 GT4 wing.
The board design was updated over the GT4 MK2 with a slightly recessed area in the middle of the board.
The wing was further designed with a specific trunk engineered with reinforcement plates for the Evo wing.
Here it is in prototype stage.
From the track to the street:
the M4 GTS rear wing.
BMW M's introduction of the M4 GTS touted its increased engine performance thanks to its water injection system and they deemed the carbon strut brace as the highlight of the car.
"Many arguments can be made about the timing of BMW M's slide into ///Marketing, this might be one of them."
Following on the E92 M3 GTS recipe, the M4 GTS featured an adjustable front splitter and rear wing.
This time around they adapted the BMW Motorsport track version from the M235i Racing Customer Car.
They used the same wing board yet revised the end plates to a smaller, less aggressive design and mounted the wing quite lower using the bottom section of the M235i Racing prototype risers.
The Final Evolution:
the M240i Customer Racing Car.
2018 saw the final evolution of the EVO wing as we know it today with the introduction of the M240i Customer Racing Car.
Relevant to this topic was the introduction of new end plate designs over the M235iR.
The end plates were larger and more aggressive. They retained the 3 holes for adjustable angle of attacks.
It's safe to assume BMW Motorsport optimizes for performance and performance alone.
Or do they.
In BMW's own words:
"The BMW M240i Racing Evo package contains, among other things, optimised engine software. New end plates for the rear wing contribute to the optical upgrade of the cars used in race series and Cup classes around the world."
Unfortunately that might be where it gets diluted.
Up next, I cover my unboxing impressions of the M240i Racing carbon wing made by Silvano.
I will cover the design differences with the original wing.