[maddog2020]

I'm actually making progress on the airbox, and wanted to document it here. I've posted some pics on FB, but here is where I'll be adding more detail.

I've had access to Louie's airbox mold and decided a long time ago to go in my own direction, partly because of a discussion I had with Louie way back in the day. I asked him if you had to do the airbox all over again what would you do differently? He told me he'd put an access plate in the bottom of the box so he could service the linkages as well as the ability to access the idle bypass screws so things could be adjusted over time. I also wanted to go a different route on an air filter because I didn't want to tilt the radiator back, and put the air filter in front of the radiator as it gets much hotter here in Texas than Oregon where Louie lived. So about 15 years ago I started trying to make my own airbox from fiberglass. I knew what I wanted the airbox to look like, I just didn't have the skills to make it happen and that was one of the reasons the project languished for over a decade. 3D scanning and printing have come a long way in the last 5 years as well as the development of the materials used. It's time to make my vision into a reality.

This is the 1st test fit of the lower airbox. some of the dimensions were off, and this is why you print and test fit stuff. This version is in pieces because to print a large piece like this will be very expensive. (about $1200) The second printing is already underway to correct some of the measurement issues.

I'm not ready to fully disclose my vision of the rest of the airbox. I will do so as I make progress. I've been floating ideas in my head for the airbox design since 2008 when I bought the ITB's and started planning. This started out as an idea, followed by crappy drawings, (I have the artistic ability of a rock) followed by wasted hours with fiberglass, and now working with a guy who has scanned my entire engine bay, and is doing the CAD and 3D printing work based on my designs.

so here we go.



This provides access to the Fuel Pressure Regulator



Linkage access



Access for the idle bypass

[maddog2020]

the round hole near the front of the airbox in the center is a vent for the AOS. I'll drill a hole for the air intake temp sensor when I decide where it will reside.

[worf]

Nice.

And here, there’ll be no trolling about the other thing.

[Geza-aka-Zombo]

Something you may want to consider is the impact the firing order has on potential air starvation of certain cylinders. I did a little study on the OEM manifold showing how Porsche handled this. See below.

I watched a video once where Ford's ICE (intake, combustion, exhaust) engineer described one of the advantages of the Voodoo flat plane crank V8 was that the firing order went from bank to bank on the engine allowing each cylinder to breathe equally.

hessank @ S4 Intake Manifold review/study

[maddog2020]

Nice.

And here, there’ll be no trolling about the other thing.

and that is why I don't post my stuff over there.

[maddog2020]

Louie mad 603HP with a similar box, however I wanted larger radius's in the corners because that does affect how the air moves around in the airbox. I've got hotter cams, as well as porting on the intake mouth shape of the heads. Louie's design was made to neck down from the 50mm round ITB to the 48x45mm cylinder head oval. this transition was 3/8th of an inch on one side to the 3/4" height on the other side so the transition from round to oval was pretty short. I had my heads ported to a 50mm round mouth to match the ITB size so there should be a little bit more flow but a lot less turbulence from that transition. I've also go much hotter cams with better lobe separation than Louie's Devek B1 cams. The B1 cams were a 2mm base circle design, and was able to add 2mm lift but very little duration, and was only what could be accomplished with modifying stock cams. My cams were developed by Mike Simard along with Harvey Crane (from Crane Cams). They were made from blanks and ground to Mike's and Harvey's specs. These are the same cams that Mike put in his 7 liter monster, not the detuned ones that GB got for Andy and other strokers. Mike's ITB"s also necked down to the factory 45x48mm oval intake ports but the transition was much smoother over a longer span of about 3 inches and started just below the butterfly. His 640HP was 100% limited because he wanted to stick to the factory port so he could sell the ITB's for people to install on cars with stock head ports. His next iteration was going to be heads like mine but he never got there. I am planning on spinning this up to 7800RPM, and my tuner thinks that 650hp at the ground is doable, he is not sure if we will need e85 to get there or not but I do have that capability with my ecu and fuel lines/pump/injectors. I just upgraded to 1050cc Injector Dynamics Injectors which are the equivalent of 100lb injectors. @55psi, they are essentially flowing 1300cc or 130lbs which should leave plenty of margin since e85 needs 30% more fuel to reach stoichiometric of 9.76:1

[linderpat]

such superb engineering!

[maddog2020]

Here is a very early airbox rendering with the longer horns in it. Need to reshape the front to accommodate the one horn that is protruding from the front of the airbox.

[hernanca]

In case it helps any, I found some air filter sizing formulas on the K&N site and applied them to the 928:

hernanca @ Air Filter Sizing