I personally cannot get my head around the poor finish inside those air boxes. It is obviously an artifact of the wet layup of fibreglass (which seems to be the main component of these airbox covers with a 'style' overlay of 1 or possibly 2 layers of CF weave on the outside you see - substantially cheaper to make that way). Had they used even 1 more layer of CF on the inside at least they would have passed the 'visual' test even if they failed miserably on the weight test.
Anyway enough about economics, and back to the more interesting point of power improvements....
I'm looking towards some more radical ideas as I move forward. The first one is to use some of the recent changes Ferrari did on the later cars such as the Scuderia and 458 to improve performance. As well actually as some of the techniques they've kept as the preserve of the hyper cars such as the Enzo.
Lets think about the journey the air has getting into the engine. Air intake from side of car
A big issue on the 360 is that the RHS (Right Hand Side) bodywork air intake is actually feeding a radiator to cool the gearbox oil and not contributing to ram-air for the air box at all. Actually only the LHS is feeding air into the air box! The intake is also partially blocked (airstream wise) by the huge front mirrors so the air is already turbulent when it reaches the intake. (Hence why GT and CS cars use different smaller mirrors and why Ferrari changed the design of the mirrors on the F430 to be more aerodynamic and actually push the air towards the intakes...). The side intakes sure look pretty but they aren't very large either so making a carbon insert that goes deeper would certainly help ram effects here too.
Looking at other performance models, this rhs oil cooler radiator was actually relocated on the 360 Challenge cars so cool air was ducted straight from the plexiglass rear screen which improved its performance quite a bit. On the F430 the radiator was dropped completely and both LHS and RHS provide high quantities of cool ram air from the side air intakes directly into the air box.
If the 360's radiator was relocated this then affords the opening up of the rhs air intake ducting so that 'ram air' could come from both sides of the car. (spooky enough just like on the F430
The next restriction to flow on the stock 360 is not the air box itself (although that itself does suffer problems - more on that in a bit) but the Air Flow Meters. Their diameter restrict flow at high RPM to the point where pressure becomes a problem but we are getting ahead of ourselves, lets look at air box design first... Air box design
On the GruppeM ram-air box they made several improvements over stock but its still not perfect (!). They firstly addressed and partially solved one of the problems of heat soak from the cats and exhaust backbox by using a heat shield and by adopting carbon instead of aluminum.) Since carbon as a material suffers less from heat-soak less than aluminum. They also allowed opening up of both sides so you could also get ram-air from both LHS and RHS of the car. This is how they where able to demonstrate improved power, they also enlarged the volume of the box but really that wasn't the main improvement, it was the switching to cone filters which had less restriction on flow (> 30%) compared to stock paper, again which helps primarily at high rpm. The air intake was in the end both cooler (denser = more power) and less restricted, more flow from both sides. It was a good attempt but still the location of the air box however still isn't what you'd call ideal however and the hot coolant overflow tank is also not the best place to have your air intake filters next too either.
Looking towards the Ferrari factory tuner, Michelotto they also replaced the factory air box with a Carbon version (less heat soak) but they also adjust the shape so that it sloped upwards (less volume) towards the rhs of the vehicle improving air flow towards the rh throttle body. They also relocated the hot coolant overflow tank to a different part of the engine bay away from the incoming air. Bosch AFM (Air Flow Meters) - Restriction
Ferrari themselves on the CS solved the diameter of AFM's restriction by going to larger AFM size (very similar as to those used by the Enzo engine infact, the afm's as used on the 599 (Enzo engine de-tuned) and 430, so plenty big enough to flow air into the 360's intake when using 1 per bank). Where they held back though was at the next step the air takes... Bosch TB (Throttle Bodies) - Restriction
That's right, the throttle bodies are also pegging the air back so that your limiting the amount of air you can get in due to their diameter. Red Intake Chamber Cover
Ferrari replaced the cast aluminum intake chamber cover with a lighter carbon cover on the Scuderia for improved weight and better heat soak characteristics.
Some after market tuners (only one I know of makes a commercially available replacement intake cover for the red air intake, in this case, Kinetix). They adopted the same approach as Michelotto did on their intake box in that they sloped the shape upwards [as used in f1 engines], so claim some benefits to their intake ( maximum flow/distribution (thins out towards cylinders further away)). They too made their intake a little bigger by 12% and also tackled the heat soak issues thus lowering air charge (lower engine/intake heat soak vs. factory aluminum manifold) by simply ceramic coated inside of their cover for maximum heat barrier
Results on just the intake where 12-14 rwhp gain just from the intake cover. Again its a good effort but it is not a perfect design and doesn't tackle the TB issue.
More power would have been possible if the restriction on the throttle body was looked at too by fitting the F430 tb's which are larger bore diameter. The next more radical step would be to relocate the tb intakes to the SIDE of the plenum rather than the standard back position. (The Enzo uses this approach, see picture of its TB location), thus removing the air boxes from the unsavory position near the cats and hot back box.)
The air boxes would then themselves need to be fitted snugly behind suitably re-design engine drip panels. This would actually reduce heat soak too since the air intake boxes would be outside of the engine bay area closer to the intake air stream. (Its still important to retain an air box design to get the pressure pulse effect, as air is sucked out the vacuum created in the space helps air to rush in to fill it). Packaging could be harder and changing the air filters would require removal of the engine drip trays but it would enable bigger gains still than anything previously gone before.
Next up would be that we've now got much more air flowing into the engine and the TB's would need mapping on the engine computers too so at this point it would be well worth swapping out the fuel injectors which are already running at higher pressure than normal. (Ferrari run the fuel pressure higher so it allows them to fit smaller fuel injectors which help with emissions). The higher pressure gets more fuel through in the duty cycle than the injector size would first suggest (hence many people getting confused about max power they could theoretically produce...). Last time I calculated it I think the stock injectors max out at around 440hp-ish. At this point your clutch becomes the next weak link. Exhaust, headers and cats
No point in ram air tuning and cooling air intake, adding more fuel if the exhaust becomes a major restriction so the free flow cats, headers and racing exhaust bypass are the other restrictions which move things along nicely. Results
With cooler dedicated air boxes from enlarged side intakes, relocated new box design, improved cone filters, larger afm's, larger tb's, carbon intake with side entrance design (ceramic coated inside), larger fuel injectors, free flow cats, headers and exhaust bypass (and suitable remapping) I estimate you expect could well see 460-470bhp @ 9,500rpm rev limit, all without opening up the unit itself.
Its an impressive engine Ferrari built here.
For reference Ferrari's tuner, Michelotto made an insane 550hp out of their 3.6 engine (when mapped unhampered by mandatory air restrictors required for competition). Their engines are a work of art... Down to Earth..
Even if you don't go this extreme there are lots of 'learnings' which can be directly applied to your car without spending big $$$. Of particular note is heat shielding of the factory air box and ceramic coating the inside surface of your standard red intake covers. Both a win-win for power by significantly reducing intake temp's. People could also experiment with ram effects by adjust the volume of the stock airbox (like a ramp or wedge shape, thin at the LHS, going more wedge shaped towards the rhs). Access to a dyno is vital to verify your gains...