SP Quick Spool Valve

[gaboonviper85]

it wouldnt create any backpressure?

Dude...forget the word backpressure!!! Back pressure doesn't exist!!! If you actually read everything in this thread you would realize that would have no negetive effects on exhaust pressure/flow as this valve is meant for low rpm low exaust manifold pressures....it only redirects the low volume of expanding exhaust gasses towards the sweet spot on the turbine wheel...once boost is achieved the valve opens all the way..

And I don't even have a turbo yet..

 

[IJ.]

^ Smarter than the average Bear <golf clap>

 

[tissimo]

For those wanting sheets, here is ABM's test of the SP valve.

The car is a mkiv (2jzgte) with a GT45R 80mm

I would of liked the rpms starting at the same time though.

 

[gaboonviper85]

^ Smarter than the average Bear <golf clap>

Now only if I could get rid of all the body hair!!!

 

[Poodles]

midrange is NUTS, but the runs aren't the same... they start and end at different times...

Anyone saying this doesn't work is a bit of a fool since they've been doing it on diesels for years (using a bit of a different system that is part of the turbine housing, this one is usable on any turbo)

 

[FullNelson]

What sort of options short of custom does the 7m have for a undivided manifold?

 

[tekdeus]

I'd like to see more tests and dyno charts. Ideally, a full pull with the valve open, one with it closed, and then a chart of the valve in operation/transition.

Here is the full ABM testing thread http://www.supraforums.com/forum/showthread.php?t=516096
Have a read through it and see what you think? Sounds like you only get 300rpm of extra spool out of this valve. It's hard to estimate if it would even be worthwhile on something smaller like a T61-67.

 

[sk6471]

I've asked about a product similar to this one on here about a year ago. I found it on an aftermarket diesel web page. The main difference with it was that it was taller and the block-off plate became the divider when it was open. When it was closed, it swung to the outer wall and not only blocked the port, but helped to guide the exhaust into the other port.

After seeing actual real world spool numbers on the graph, the SP model seems to increase spool by 250 to 300 rpm. IMO that's not that impressive, but it looks like a viable alternative to ball bearing turbos at about the same cost. You get same results w/o having to run coolant lines or worrying as much about oil quality and return flow. When used with a DBB turbo you could increase spool by 500 to 600 rpm over a standard turbo, but at insane costs. Still not worth it in my book.

In a world of turbos that can flow 600hp worth of air and hit 30 psi before before 4000 rpm on a 3 liter motor, I can't see why anyone would buy this product.

 

[Poodles]

The RPM that it affects might not be long, but the power gain is nuts, seeing around 100HP more because of the valve.

I'm just curious if it fell off hard up top and that's why they ended the pull...

 

[tekdeus]

In a world of turbos that can flow 600hp worth of air and hit 30 psi before before 4000 rpm on a 3 liter motor, I can't see why anyone would buy this product.

Which turbo can do that? On a stock 7M head? (just curious)

The cost is hefty, as are going with BB turbo instead of a journal bearing, but you get that wider power band every single pull as long as it works... not a bad trade off.

 

[IJ.]

The way Dyno's read if you can begin with more power it'll show as a huge jump in the top end, I found this when I went with the lightened crank it allowed the engine to ramp into the load zone of the dyno sooner.

 

[tekdeus]

Here is the valve dyno test result on an SP63 turbo(Tested by SP). Not bad! The red is with the valve open, and the blue is with the valve in operation

 

[tissimo]

^ those are impressive numbers.

 

[Poodles]

Damn.... like I said, the midrange is NUTS.

 

[sk6471]

Ok, that graph shows a spool of 300 rpm earlier. I just don't get it. Effectively cutting the A/R in half only shifts the torque curve left 300 rpm. There must be inefficiencies in exhaust flow caused by turbulence when the valve is shut, slowing the acceleration of the wheel. Or does hypothetically cutting a 1.08 A/R to .54 only spool a turbo 300 rpm sooner. I guess that's not a perfect analogy because this product doesn't change the angle at which the exhaust hits the turbine like a smaller housing would. It only doubles the speed that the gas is traveling when it hits it.

Maybe the addition of something to guide the exhaust gas to the open port would improve the flow. Also a custom asymmetrical turbine housing would help. Have a smaller A/R on the side that's always open and a larger A/R on the other one. When the valve is closed, it will spool even faster and when the valve is open, more exhaust can flow out the larger more efficient side.

Which turbo can do that? On a stock 7M head? (just curious)

In theory, a GT3582R HTA could with cams and a good tune, but they're stupid expensive.

 

[tissimo]

Thats about right for the spool. The a/r doesn't make drastic(1k faster) changes in spool time.

 

[Poodles]

sk6471: that's almost EXACTLY how the Honda turbo works on their SUV... Has a flapper to open up to the larger AR once boost is reached so it doesn't choke the engine.

 

[tekdeus]

They're having a $499 group buy price that ends today, I just ordered one. Every ounce of spool is worth it to me since my car is a 99&#37; street car. The turbo I'm now considering is the Precision DBB billet exteneded tip 62mm :drool: This combo will have more power and spool faster than a GT35r.

 

[Adjuster]

Interesting stuff.... On bigger turbo's, say over 70mm, this will help with low end power, and not really cost much, if anything on top. (Especially if you can now run a larger AR housing, but still have power down low since the "true" AR is now "half" when the valve is closed.

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.

I see no downside on this, even with the shaft of the "throttle" plate going right through the middle of one runner opening.

Sure, a flapper style door that when open sits into a recessed pocket on the runner, and is completely out of the way would be even better, but is that really needed? Another benefit of the flapper style door might be to design in an angle, so you have in effect a funnel shape when the door is closed.. and that funnel wall is removed when the flapper is opened up and out of the way.

Very cool ideas, and competely simple things like this are often the best when your dealing with exhaust parts that move. (Simple and reliable.)

I would also make the actuator bracket and shaft longer to keep it away from the heat as much as possible. A simple Hobbs switch like SP sells is all you need to control this. It's passive, and only opens the door as the pressure comes up. RPM is not a variable that matters. Neither is your throttle position or any other normal variable.. Only boost pressure counts here.. If it's high enough, then you need to open the door. Otherwise, it's just mental masturbation.

 

[IJ.]

I liked it so much I bought one