Air outtake - engine bonnet Mansory Carbon for McLaren 720S

Air Outtake Engine Bonnet Mansory Carbon for McLaren 720S

The Mansory air outtake engine bonnet is the functional rear bonnet variant in the carbon programme for the McLaren 720S — the panel that sits over the mid-mounted M840T V8 BiTurbo and carries an integrated air outtake aperture for thermal extraction. It belongs to the wider Mansory Carbon Fiber Body kit set for McLaren 720S, and within that roster it is the option specified by owners who push the car hard — repeated track sessions, sustained motorway work in hot ambient, hill-climb stages — and want the engine bay to breathe outwards rather than recirculate. The Monocage II carbon tub is unaffected; the bonnet is a bolt-on body panel that swaps for the OEM lid while preserving every Active Aero, lighting and cooling interface beneath it.

Construction & Materials

The panel is laid up from aerospace-grade prepreg carbon and cured under autoclave temperature and pressure. Mansory's standard surface is a 3K twill weave with deep-gloss UV-stable lacquer; a 2x2 plain weave or forged-composite finish can be specified, and the visible surface around the outtake aperture is built up so the weave reads cleanly even when hot air visibly hazes the panel after a hard lap.

• Layup: prepreg carbon over closed-cell foam and Nomex honeycomb in the high-stiffness zones around the outtake
• Cure cycle: autoclave, ramped temperature/pressure profile, post-cure for dimensional stability
• Weave: 3K twill default; 2K plain or forged-composite optional; aperture lip uses oriented fabric for edge integrity
• Wall thickness: ~1.6–2.2 mm across the visible skin, thicker in the aperture surround and the rear hinge zone
• Weight: roughly 30–40% under the OEM bonnet assembly depending on aperture and reinforcement spec
• Hardware: factory hinge geometry, factory latch, factory gas struts, factory wiring pass-throughs all carry over
• Finish: deep-gloss two-pack lacquer with UV inhibitor; raw-weave matte and satin lacquer on request
• QC: dimensional jig check against an OEM master, hairline-crack and pinhole inspection under raking light, aperture-edge tactile pass

Design & Visual Function

The point of this bonnet is the aperture itself. The 720S V8 BiTurbo runs hot — twin turbochargers, intercoolers and the catalysts all sit in a tight mid-engine bay, and even with the OEM cooling architecture there is a meaningful pool of hot air over the engine after a sustained pull. The integrated outtake gives that air a vertical exit path. On a closed engine cover the heat has to migrate sideways through the rear quarter venting; with the outtake bonnet the worst of it leaves the bay directly upward, which lowers the soak temperature, helps turbo cool-down at the end of a stint and reduces the duration of post-shutdown heat-rise that ages adjacent rubber and plastics.

Visually the panel is theatre as well as function. Stand behind a 720S after a fast lap and you can see hot air shimmer above the outtake — the carbon weave reads through that shimmer in a way the OEM glass cover cannot replicate. Mansory's geometry keeps the outtake aperture aligned with the car's centreline and tucked under the rear-glass shutline, so the top profile from the side stays clean. The panel sits flush with the rear deck when the bonnet is closed and the aperture is recessed enough that it does not catch a forward-flow streamline; airflow exits, it is not punched into.

Because the lid is the rear of the car visually as well as structurally, weave alignment matters. Mansory aligns the twill diagonals symmetrically across the centre seam, mirrors them across the aperture surround, and brings the visible weave into harmony with adjacent carbon — the rear fender air intakes, the engine cover (where specified instead of this bonnet), the rear bumper and diffuser. Owners running a full carbon roof-to-tail look usually pair this bonnet with the rear-fender air intakes and the air-outtake grill cover.

Compatibility & Fitment

The air outtake engine bonnet fits the standard McLaren 720S Coupe and the 720S Spider, model years 2017–2023. It is NOT compatible with the 765LT — the Long Tail is a separate platform with its own bonnet, vent geometry and aero map. Beneath the new panel everything OEM remains: the hydraulic deployable rear wing and its Variable Drift Control plumbing, the front Active Lift mechanism, parking sensors, rear-camera washer aperture, latch and hinge hardware, gas struts and the factory heat shielding immediately above the V8. The aperture is shaped so that no warm-air path collides with the rear-glass demister or the engine-bay drain channels. Mansory's part replaces only the visible bonnet skin and its integrated aperture; nothing forward of the windscreen or below the engine deck is altered.

Installation & Reversibility

Allow roughly 3–5 hours for the swap, including bench prep on the new panel, transfer of the OEM heat shielding and underside hardware, latch alignment, gap and shutline check around the rear glass and the rear quarters, and a settle period after first heat cycle. The work is fully reversible — remove the Mansory bonnet, refit the OEM lid, and the car is exactly as it left the factory. No drilling, no trimming of body structure, no modification to the Monocage II tub, no work on Active Aero hydraulic lines. Recommended installer is a McLaren-certified body shop or a Mansory-trained installer; the heat-shield retention check and the aperture-to-rear-glass shutline benefit from someone who has done this car specifically.

Pairing within the Mansory 720S programme

This bonnet is the functional half of the engine-bay carbon trio, and most owners specify it alongside one or two siblings. Pair it with the engine cover as the closed-bay alternative — owners who prefer not to run the outtake aperture (cleaner show finish, fewer ingestion considerations under sustained rain) sometimes order both and switch by use case. Pair with the rear air outtake grill cover as the matching mesh that finishes the aperture itself in carbon. And pair with the primed engine bonnet if a full bonnet-front-and-rear carbon package is on the build sheet — the primed bonnet is the FRONT lid (frunk), this air-outtake bonnet is the REAR lid; together they bookend the silhouette in carbon while keeping the V8 visible from above.

Maintenance & Durability

Lacquered carbon on a hot-zone panel asks for an honest care routine. Wash cool — never on a sun-soaked deck — using a pH-neutral shampoo and a clean lambswool mitt; avoid alkaline traffic-film removers, ammonia-based glass cleaners straying onto the lacquer, and any abrasive sponge or brush. A two-layer ceramic coating protects the visible weave against UV and surface oxidation; a quality carnauba is fine if reapplied frequently but does less for UV. Inspect the aperture surround quarterly — this is where heat soak is concentrated and where any micro-defect in the lacquer will show first. Stone-chip risk on a rear bonnet is low compared with a front splitter, but a single-stage paint protection film panel over the centre crown is reasonable for owners doing motorway work behind heavy traffic. Carbon-ceramic brake dust is hot and abrasive but stays in the wheel arches; keep it off the bonnet by rinsing wheels first during a wash. If the panel is chipped, professional carbon repair restores the weave optically and structurally — Mansory documents an approved repair workflow.

Lead Time & Warranty

Lead time runs 4–8 weeks from order confirmation, reflecting the autoclave cure, the aperture build-up and the lacquer-and-cure cycle to Mansory's bespoke standard. The panel ships with a 12-month manufacturing-defect warranty covering layup, bonding, hardware integration and finish; consumable damage from impact or chemical attack is excluded.

FAQ

Q: Will this fit my 765LT?
A: No. The 765LT is a separate platform with its own bodywork. This air outtake engine bonnet is for the standard McLaren 720S Coupe and Spider only.

Q: How is this different from the engine cover and the primed engine bonnet?
A: Three different parts on the same car. The primed engine bonnet is the FRONT bonnet (over the frunk). The engine cover is the closed REAR cover with no outtake aperture. This air outtake engine bonnet is the REAR cover variant with an integrated functional aperture for hot-air extraction.

Q: Does the outtake aperture compromise OEM heat shielding or wet-weather sealing?
A: No. The factory heat shield above the V8 is retained, the aperture is geometrically positioned and channelled so water exits where it always exited, and the engine-bay drain paths are unaffected. Owners use the car in rain without issue.

Q: Does it interact with the deployable rear wing or Active Lift?
A: No. The Active Aero hydraulic system, Variable Drift Control logic, deployable rear wing and front Active Lift all remain OEM and untouched. The bonnet sits forward of the wing entirely.

Q: How much weight is saved versus the OEM lid?
A: Roughly 30–40% off the OEM bonnet assembly depending on aperture spec and reinforcement; the absolute number is small in the context of the car, but mass removed high-and-aft is good for polar moment.

Q: Raw weave or lacquered finish?
A: Deep-gloss lacquer is the default and the most durable on a heat-cycled rear panel. Satin lacquer and exposed-weave matte are available; raw weave is technically possible but asks more of the owner's wash discipline and the repair workflow.

Specify this bonnet alongside the engine cover, the rear air outtake grill cover and the primed engine bonnet to complete the engine-bay carbon package. Order or ask for finish samples via WhatsApp +44 7488 818 747 or [email protected].