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SVXride:
We're probably not talking about changing the throttle body or the MAF cross sectional area, so, we'd really like to know the pressure drop between the airbox and the throttle body butterfly. Can you measure pressure at the little plenum where the plastic snorkus connects to the two throttle body throats? I was going to say we could use manifold pressure, but unless the engine is fully loaded at 6000 rpm, it won't be WOT, so there will be some unknown pressure drop across the partially open butterflies. If we knew the pressure drop between the airbox and the throttle body inlet at any given rpm, we could calculate the air flow based on the rpm, then calculate the velocity pressure based on the airflow, then, the rest of the pressure difference would be dynamic and frictional losses in the snorkus. Those, we might be able to do something about.
I agree with you, that the reason the aerodynamics were compromsied was packing the intake pathway into a constricted space, and making provisions for servicing (the corrugations).
As far as the CFD, its on my list. I'm going to have to sneak it into the queue. We're so busy right now, my CFD people are backed up for a couple of weeks, and I'm fielding internal emergency complaints from my partners. I'm probably going to have to draw it up and bring in the drawing, because dumping the actual unit I removed from my car on somebody's desk is not the most discrete way of going about getting an analysis done.
Silver Spear:
I think the problem we are looking at here is complicated the really high velocities in the inlet tube. Some vane-axial fans have discharge velocites of 7000-8000 fpm, but inlet and outlet configuration can change the required power to deliver a specific mass flow at a specific pressure by a factor of 2 or more. The problem is that you have already utilized a static pressure drop to get your air stream up to velocity to get through the MAF. The smartest thing to do is to keep that velocity and guide that high velocity stream smoothly and directly into the throttle body inlets. It is all about keeping the momentum of the air stream. Kind of like driving on the track.
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95 LS-i Red, 31,xxx; bone stock for now; Daily Driver
94 LS-i Emerald Pearl, 106,xxx,; 246 whp; Tomyx snorkus and HKS Cold air intake; PWR aluminum radiator, silicone hoses; Inline thermostat; enhanced coolant routing; external power steering and oil coolers; Phenolic intake manifold spacers; 2004 WRX 5 speed transmission; ACT Clutch Kit, Heavy Duty Pressure Plate, Lightweight flywheel, performance disc; Group N motor mounts; ‘07 WRX 4-pot front calipers, cryo-treated slotted Tribeca rotors; Hawk HPS ferro-carbon pads; Frozenrotor rear slotted rotors; SS brake lines, Axxis Ultimate pads; Rota Torque 17x8 wheels; 245/40-17 Bridgestone RE01-R's; Koni inserts with Ground Control coilovers, Eibach springs; K-Mac camber/caster adjustable strut mounts; Urethane swaybar bushings; Bontrager rear sway bar; Urethane differential bushing; Custom Whiteline adjustable rear lateral links; Outlaw Engineering forged underdrive pulley; custom grind Web intake and exhaust cams (11 mm lift, 250° duration); solid lifters; CP custom aluminum forged 11 to 1 pistons, Brian Crower coated SS intake & exhaust valves; Brian Crower upgraded springs w/ titanium retainers; NGK sparkplugs; RallyBob (Bob Legere) ported and polished cylinder heads; Eagle H-beam rods; ACL Bearings; Cometic Head gaskets; ARP head studs & fasteners; Hydra Nemesis EMS; Wideband O2 sensor; 740cc Injectors; Walbro 255lph fuel pump; Upgraded WRX starter; Equal length SS headers (3 into 1); dual Magnaflow cat converters; 2 into 1 into 2 SS exhaust with Bullet muffler; OT Fiberglass hood; Oil pressure gauge; Programmable shift light,
2017 Subaru Forester XT, metallic dark gray, 29,xxx
2005 Porsche 911 Turbo S Cabrio, 24,xxx
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92 LSL Dark Teal, Smallcar Shift Kit - sold
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