Socal_Tom

So admittedly I am very late to the party here, but is the stock intake really so restrictive that honing it out would give you a bump in air flow with less alternative engineering?

Edit - I am all for clever fabrication, just asking...

https://boneheadperformance.com/extr...-hone-pricing/

dr bob

Mark --

Standing by for your sketches/drawings with dimensions noted, showing the AM ports and spacing vs the 928 head ports and spacing. Look at the wall thicknesses of the AM casting to determine how much weld metal will need to be added and existing metal removed, and how you'll be able to make the transition from the AM metal to a connecting sleeve that will mate each AM port to fit into Hans' mounting flange nozzles.

You'll need to have a 928 engine block with heads mounted to get the spacings just right. Or have a sheet of aluminum (10+mm thick) waterjet cut to match the port configurations and bolt locations of the heads. the block will be a lot better as you progress, as you'll be able to include the water bridge and the oil neck.

Your next post should include these drawings, where the "dream" turns into a "design". Add schedule and budget, and you will have the beginnings of a "plan".

mark kibort

thats what i was thinking too, but its bends and turns, as well as inlets are very disruptive to flow. Anderson bored his out thinking this would provide gains and even with a larger throttle body, no gains were to be found. i was thinking we could take the structure and gut it. leave the inlets from the throttle body, and then refab with all new runners/ inlets. but thats just a thought i had.

dr bob

Extrude-honing has generated mixed results in the S4+ intakes. Better results, but very time consuming, have come from actual internal modifications to the stock S4+ castings. The original manifold is a compromise for space, and a lot of consideration given to driveability and a flat torque curve, rather than peak horsepower. Good cylinder filling at lower engine speed, in consideration for the auto gearboxes mostly, was particularly important as witnessed by the dual-path design with the flappy valve.

Socal_Tom

So they knew what they were doing in other words.

Subscribed to see how this progresses. Good luck Mark!

V2Rocket

i think youll love this if you havent seen it before...
very relevant to the thread.
want a manifold for XXX rpm ?
plug and play...


http://www.superchevy.com/how-to/eng...runner-system/

mark kibort

yes, the stock intake is fantastic for those that really dont want be active with the gear box after all, the flappy gives the "flatter" torque curve and bump in the HP down low. however, if you drop a gear and dont mind the RPM revs, you get even more regardless of what is happening down low.

yes and for those that go WOT at 3000, the dual path design , so many street cars employ is a good design. I removed flappy long ago and never looked back, but i drive the car different than most. i never floor my car below 4500rpm, its pointless when you have a gear box to work with. however, driveability, is the main gain here. SO, the reason for the replacement for the S4 intake, is there really no racing need for lower torque or HP benefits if i can gain something up top and use the gears and the UPPER RPM to take advantage. After all, flat torque curve , means, " rising HP curve" .. I'll take a falling torque curve any day of the week for any given HP level!

V2Rocket

I'll sell you a pair of (aluminum) 944S2 intake manifolds if you want to cut them up and make a common plenum.

Runners are a little bigger than a 928S4 intake port and 14" long so you can cut them down to suit your target RPM range, the flange-end bolts onto a 928 head...just flip one end for end.

mark kibort

that was one of the original options.... but the entire goal here is to make something anyone can bolt up with little cost and as little work as possible. the secret sause is really the runner diameters and the bell mouth inlets in the plennum... i would hate to picture what i would cobble together using that.

thanks though!!

Dr bob, check out the S4 intake air path as it goes into the heads. its like a right angle to the head! (the middle cylinders. and the ends are not much bettter)

dr bob

We know.

Get back to us when you have a design. All this stuff in the meanwhile is smoke.

mark kibort

dont you want to be involved with the planning?.........its the best part!
Ill need to access the lower intake manifolds........ do you think hans would share the drawings so i can make it , for a fee? otherwise, i have to wait until his next run , OR, i can always lap off the intakes bases of the 944 intakes.... heck that might even work out better.
AND, i either need a dummy S4 intake or the template i see others using as a jig.
thoughts about that?

V2Rocket

find a machine shop with a cnc plasma or water jet machine and give them an S4 intake manifold gasket and ask them to duplicate it in 3/8"-1/2" aluminum.

dr bob

We've shared plenty of hints and tips. Planning comes AFTER you have a design. Three things make a real Plan: Scope, Schedule, and Budget. Scope in this case equals a design. Then you get to look at your available budget and build a schedule based on scope (the plan), availability of talent (the welder/fabricator plus Hans' parts (really part of Scope), and budget. Mark, until you have those pieces, you have a Dream.


Why do you ask that question here? PM or call or e-mail Hans. He may loan you a set of 3D-printed prototypes, or give you the dimensions, maybe even a dimensioned sketch. He has shared the CAD images here previously, including links to a 3D viewer that lets you rotate the images. Question goes directly to Hans for any of that.

The choice of a 944 manifold flange as a "base" is always interesting, but there are some serious metallurgical considerations there around welding; better to have Hans make a set for you in an alloy that can be welded to your AM intake, whatever metal that is?.
[/quote]

Add it to your list:

Item 27: make a jig


And you don't really need a "dummy" S4 intake. You Need A Dummy S4 Block and Heads. Unless you want to duplicate the S4 intake, what good will a dummy version do for you? You'll want at least the block or the thick aluminum template to weld on. Welding aluminum involves some pretty serious expansion and contraction as the assembly heats and cools in odd directions, so holding it rigid and sinking some heat seems like a requirement. Maybe have the flanges made with enough extra thickness that it can be milled flat once all the welding and grinding are done. Talk to your welder to see how he feels about all this, along with the access issues he'll face trying to weld any of the inner connection faces.


---

Socal_Tom

Time to break out a 3D printer

mark kibort

I need the template to mount the intake runners . As long as that jig matches the head and block, it will work. in other words, if i just match the foot print of the intake (s4) it will fit on the engine, right? however, not adverse to have a block and some dummy heads.(with gaskets)

why cant i use a stock intake gasket?