SP Quick Spool Valve

[InFrnt0fU]

Instead of having one "door" shut, causing turbulence, why not have these valves on both sides and just open them both slowly (variable timing). I would think this would smooth things out, and the spool could REALLY be controlled precisely.

Taking a stab at it...02

 

[Doward]

Yes, it works. This is nothing more than a diesel function on an automotive application.

I'm surprised, however, from an engineering POV, that they didn't take steps to do this in a much more productive way, using the blocking plates to smooth the transition into the single entry point.

That's alright, it'll just give me something else to design for the MKIII community

 

[tekdeus]

I liked it so much I bought one

If you're going to be running low boost, you might want to know that another SF member who also bought one told me that his valve starts to open at 7 psi and is 90% open at 12-13 psi and fully open at 15 psi. Sound Performance told me that the valve begins to move at 5 psi.... fully open by 11-12 psi.

Here's another interesting idea:

 

[InFrnt0fU]

Here's another interesting idea:

A little rough but certainly the right idea.

Turbo Rudder Valve...patent pending lol.

 

[Kristian_Wraae]

What we really need is a VTG turbo that doesn't cost a trillion and with a T4 footprint.

 

[tekdeus]

As IJ pointed out, placement of the valve is important, you want the open side to hit the major side of the exhaust wheel for the most tourqe effect possible.

SP designed these so that you pretty much have to close the port closest to the turbo center. They also said in their thread on SF that they tried it on both ports and noticed no real difference. Looking at the divided turbo cutaway pic below, which port looks ideal?

 

[IJ.]

The one closer to the centre as it directs the gas to the tips of the wheel.

 

[Doward]

Tekdeus, the pics you posted are almost 100% exactly what I had in mind to build.

 

[tekdeus]

The one closer to the centre as it directs the gas to the tips of the wheel.

You mean close that port? Are the outside wheel tips longer on the side closer to the output?

 

[IJ.]

No it should remain open

 

[tekdeus]

The one closer to the centre as it directs the gas to the tips of the wheel.

Which tips are you referring to? The larger part of the turbine or smaller?

 

[IJ.]

The larger diameter Brad, ever blown an air or water hose onto a wheel?

Moves easier/faster if you spray on the outer edge
(leverage at work)

 

[foreverpsycotic]

If you are having a standalone control it, do not have the valve crack period. SP said the crack pressure is @ 5psi (according to what was said earlier). Keep it fully closed till 1/2-2/3 of your total PSI. It will transition like the stock 2jz twins running sequentially, hard and instant.

You could also use a EBC to do the same thing.

 

[tekdeus]

I had a close look at my GT turbine wheel today. The outside edges of the wheel are 100% perpendicular, but when looking a certain angles, can have the illusion that one edge is longer.

Now looking at the shape of the volutes in the pic below, it appears that if one port was closed, the gas would push out at an angle, correct? It looks like gas coming strictly out of the left volute would have more momentum towards the downpipe outlet, whereas the right volute would push more towards the CHRA. If this is true, and assuming we are trying extract more rotational energy from a low volume of fast moving gas, which would be more effective? Perhaps closing the port closest to the CHRA would have the gas firing at a more forceful direct/perpendicular angle against the outside edges of the turbine? The gas would have to make a sharper turn to flow out of the turbo, which would be bad for flow, but could be best for harnessing that extra gas speed the SP valve is providing. If the turbine has more resistance to flow that should translate into faster spool using the right volute compared to the left.

 

[sk6471]

I agree. I would block the left one (front one). Not only is the exhaust running the wrong way, utilizing more of it's energy, but the empty space would also act as on insulator between the compressor and the turbine.

 

[Poodles]

It has to flow out of the turbine, the air will have more contact if it starts deeper in. I'd block the one farther from the CHRA

 

[tekdeus]

I agree. I would block the left one (front one). Not only is the exhaust running the wrong way, utilizing more of it's energy, but the empty space would also act as on insulator between the compressor and the turbine.

Good point, it should keep the CHRA and compressor a bit cooler. Hopefully it is safe to be heating 1/2 of the exhaust housing 95% of the time. Any chance it might crack over time? I hit 1500+ degree EGT's on those long hot uphill highways heading to Nevada.

 

[jdub]

It has to flow out of the turbine, the air will have more contact if it starts deeper in. I'd block the one farther from the CHRA

^^^ Got it right

Brad - keep something in mind...the turbine blades are shaped like a wing...the flow coming out of one side is at a higher velocity. Higher flow along the curve will have what effect?

Once the turbine housing heats up, it will transfer heat to the center housing. That "empty air space" isn't going to do squat from a thermal stand point.

 

[IJ.]

Brad: You're over thinking it it's beauty is it's simplicity

 

[tekdeus]

Brad: You're over thinking it it's beauty is it's simplicity

I'm over thinking it because I may have to modify the valve/manifold to work in a way it's designers did not intend: to block off the outer port. :aigo:

Maybe I could test it somehow? Maybe I could use my air compressor to pass a very small amount of air through one port, and see which port is able to rotate the wheel first. Would that be semi-conclusive, since we're trying to see which is better at low volumes of gas?