Overview
Launching on June 15, 2022, the v0.25 update to BeamNG.drive brought with it the single biggest addition to the playable vehicle roster thus far: the Civetta Scintilla, an early-2020s Italian supercar with svelte bodywork, butterfly doors, a meaty V10 engine, and the most advanced electronic driving aids of any vanilla BeamNG car yet.
It's brutally fast as expected, but it isn't the most agile at higher speeds, even if it can still drive circles around the Bruckell Bastion muscle car. And though the game's massive hillclimb splitter and wing do their part to make cars like the hillclimb-spec Hirochi SBR4 handle as if on rails, they're noticeably less effective on the Scintilla. It was because of this downforce-related inadequacy in spite of the Scintilla's straight-line prowess and potential as a platform that I finally tried my hand at a proper BeamNG mod, with scratch-made aero to put the twin-turbo engine's enormous power to work around Spa-Francorchamps.
The result was the Scintilla "Acquarossa", the name being an Italian calque of Eau Rouge, the famous left-hand corner at Spa that segues into the high-speed uphill right-hand bend known as Raidillon.
BeamNG mod repository link
The regular hillclimb aero works on the Scintilla, just not to my liking (BeamNG.drive)
Initial concept sketches
Concept
Given how much effort seemed to have been put into the Scintilla's design (as per this February 22, 2022 teaser), I decided to follow suit, producing a few concept sketches for the diffuser and wing.
Ideas ranged from splitter-mounted canards roughly mimicking the curved front splitter of the Aston Martin Valkyrie AMR Pro and a rear vertical fin to large Bugatti Vision GT-style endplates and a Group C-style double-decker wing. The overall concept, however, was an aero package that would rival the most extreme time attack setups while also (somehow) complementing the Scintilla's sculpted bodywork, largely (but not entirely) forgoing restraint in favour of reckless abandon in the process.
Rear Diffuser
I wanted to incorporate the existing vertical carbon fibre strakes on the sides of the performance bumper into my design, but at the same time also have the wing endplates span nearly the bumper's entire height. Therefore, said strakes instead formed the ends of the rear diffuser, helping secure it to the rear bumper in the process. A pair of struts and bulkheads were added to the diffuser to connect it directly to the Scintilla's rear subframe. The extent to which the diffuser protrudes from the rear of the car was influenced by Super GT cars, in particular the Lotus Evora GT300.
Rear Wing
Comprised of a curved dual-element design, the rear wing and endplate assembly is secured to the diffuser and body at six points in total. Two of those points are the swan-neck wing stays, to which the two linear actuators that control the active upper wing element are also attached.
Front Splitter
The Acquarossa's front splitter is of a single-piece design with integrated canards, inspired by those on the Bentley Continental GT3 Pikes Peak as well as aircraft box wings. Although the initial sketch shows the canards connecting to the sides of the bumper, this would have resulted in next to no canard surface area, so they instead connect to the carbon fibre trim on the performance front bumper immediately below the front fender air tunnels.
Rear Undertray
After Automation-BeamNG content creator fillman86 pointed out the gap in the underfloor ahead of the diffuser present in the initial release, I realized I could add a separate undertray part to the Scintilla's skidplate slot. In addition to compounding the effectiveness of the diffuser, this undertray also serves double duty as a skidplate, with two bare metal ridges along its bottom surface to step in when the immense downforce gets the better of the racing shocks.
Physics and Parts
In spite of BeamNG's world-class softbody physics, its aerodynamic model is a bit basic where motorsports-level aero is concerned, though it remains perfectly adequate for most other scenarios. To elaborate, as of v0.33, BeamNG does not yet natively support ground effects (or slipstreaming, but that's not relevant here). The approach I thus ended up taking—using the regular aero model for the diffuser in addition to the other aero parts—does make the diffuser and undertray too effective in certain scenarios, but the only alternative was writing custom Lua code based on what Camshaft Software has done for Automation exports, which I lacked the know-how to make from scratch.
The rest of the aero parts perform as they would on any other car (the sheer amount of downforce they produce notwithstanding), though I did add downforce-producing variants of the racing hood and performance front lip to augment the splitter and canards.
Other parts added as quality-of-life measures include a stronger rear tailgate that doesn't warp at speed, tweaked exhausts that are angled slightly upwards to account for the diffuser, blanking plates for the front bumper reflectors, and a custom accessory mode screen for the digital racing dashboard that features the Acquarossa logo. The "Stradale" ("Street") configuration of the Acquarossa is also equipped with a wing-mounted CHMSL and reflectors on the lower wing endplates to make up for the reflector-less modified rear bumper.
Active Wing
Although the Acquarossa does use Lua code, it's only to control the active wing. As a result, it's much simpler in nature and only consists of a few logical expressions that read the vehicle's speed and some inputs.
The wing is normally raised, but lowers to produce less rear downforce when the driver applies near-full throttle above a speed threshold of 150 km/h (93 mph), assumes an intermediate position if the driver applies less throttle or coasts above the speed threshold, and raises completely if the driver steers or applies the brakes above the speed threshold.
Stradale configuration with active wing fully lowered (BeamNG.drive)
Gallery
