mycarslow

thats just what i was thinking

HiProfile

Weird how I've never seen this thread, i actually found it on google. I've been wanting to make this for about a year or two - I actually have someone's 4.0L datalog graphs when they covered half a BIG borgwarner turbine inlet, maybe a HX50. He managed 6.3psi by 5100rpm with both open; with one closed he made ~6-7psi by ~3100rpm, and creeped up to 8.4psi by 4600rpm (kinda hard to read the graph, only shows min/max). So on a 4.0L he quickened spool by 40%. Imagine a 57trim on a D16 with a .63ar stg3 hotside hitting 10psi by 3300rpm and making much more top-end....

Honestly I think even $499 for that valve is bullshit. It looks like a thick flange, MAYBE made out of a cast iron or special steel to be it's own bearing for the shaft, and MAYBE $15 in stainless steel. I can get a 12" rod and 12"x12" plate of SS309 for $45, and a chunk of 1/2" thick uncommon steel (for bearing purposes) for $40, which makes multiple valves. 309 is used in furnace enviroments, corrosion-resistant to 1470F and isn't weakened by the heat. Its also not a new idea, just one that hasn't be produced - I saw a patent that lists "Honda genki nignog" (weird full jap name) explaining a mix between this valve and a VNT setup, and it was applied for in 1989. And if you don't recall, the RDX turbo has a weird dual-volute design, except stack on one another. It has a flapper that opens to double the effective AR of the turbine.


If anyone wants to really make something cool, it will be like my idea (similar to the maxima, and i plan on making it before summer) - a flapper that diverts the gases, but when 'open', it divides the manifold into a regular dual-scroll setup. Also the flapper is ~1" by 2", so it can't be sucked in enough to hit the fins if it breaks. I will be making out of mostly stainless, maybe some odd ferric metal for sealing the shaft if the soot doesn't lube well enough, or if it leaks. I don't expect leakage to be an issue, worst-case I'd weld in a specific material, make hold the shaft for 1", and have a shop ream it straight. I *highly* doubt that it will 'burn out' like a valve will, because the gases at that point are not only under much more pressure, but much hotter. You get maybe 40-50psi in a exh mani with high-boost, whereas you get more like 1500psi at peak cyl pressure. Further proof is the leaks people here have with CDM manifolds. My OEM manifold is warped, and you can see the sooty exhaust bypassing the gasket - the aluminum is still all there, despite the hottest exhaust gas hitting the aluminum.


If you really wanted to go crazy to seal that shaft, you'd get the right type of alloy tube, weld or press it in, remove the extra, then ream it to fit a precision-ground rod. White cast iron can take the heat, has anti-wear properties, and becomes your high temp bearing; however, I'm not a metalurgist. That would add at most $150 for top-shelf ---- & labor. I'm telling you guys there's many ways to skin this cat, cheaply.

Smith-02

the flap needs to be offset like a chimney flue to keep flow restriction out of one of the ports

Tom-Guy

Mk4 Supra has this. And they throw them away. Hint hint.

Smith-02

so do s4 rx7's

HiProfile

The mk4 supra also has TWO CRAP turbos, neither with divided turbines, and an UNdivided manifold. The system takes two crappy turbos and effectively cuts turbo #2 out of the intake & exhaust systems until it needs it. Research "exhaust gas control valve" and "intake air control valve", those are the names Toyota gave to the two valves that stop flow out of the turbine and compressor of turbo #2 (right side in picture link). The 'quick spool valves' proposed here preferably use a single big turbo, preferably use a divided manifold, and preferably use a big downpipe. Link to the stock Supra system.

http://www.max-boost.co.uk/max-boost...ke_exhaust.gif



My idea is totally different than the fail that is the supra manifold. I'm proposing a totally divided manifold/turbine with a valve section between the two. When the valve is closed (~26* angle from vertical), it closes off a turbine volute and undivides the manifold, BUT effectively HALVES the turbine volume (AR#). When open (0* angle from vertical), it opens the 2nd turbine volute, but totally divides the manifold. Each volute is fed by only 2 cylinders. Low RPM = fast spool from tiny AR#, mid/high RPM = high HP from large AR# and divided manifold.

Tom-Guy

Fucktard, the "exhaust gas control valve" does the same ---- as your flapper idea does, but it's made out of better ---- manufactured with OEM quality. Take a look at one and stop being so goddamn dense.

Smith-02

toyota has a hardon for using vsv's on everything

caged

A rotor doesnt need one of these. My 13b bridgeport didnt have a problem spooling a t04e with a 1.32A/R hotside.

t_cel_t

screw you with your 6 power pulses per rev