I've been weighing some options on my build and what size turbo and stuff I want to go with and I've been doing some reading and alot of the Turbo Supra guys are having some pretty cool results with the Sound Performance quick spool valve:

http://www.spracingonline.com/store/...ool_Valve/3643

Anyone considered trying one of these out yet? Seems like guys are seeing an increase in spool time and midrange torque as well without sacrificing horsepower. Little pricy but it could be worth a shot for a street car looking for some midrange

 

I asked the same question about a year ago and was told to buy a proper sized turbo. I also could not find 1 person on this board using it. I still like the idea but after some thought using a ramhorn manifold the qsv might place the turbo to low to drain properly.

 

I'm just trying to think outside the box here like yourself. You could buy a proper sized turbo of course, I had considered running a larger turbo/qsv because my car is most likely going to see pump gas 75% of the time and being able to make more power on pump gas would help.

Has no one really tried this yet?

 

prolly cuz most of us dont run twin scroll, i would love to see back to back dyno pulls on a b series with and without qsv.

 

You'll need an AEM or a standalone with spare PWM-based outputs, or at least multiple spare general outputs to make it a fully streetable setup.

The main issue lies on the change of VE whenever the valve opens, and it's a big VE change as well.

10 PSI at 0.48 A/R and 10 PSI at 0.96 A/R requires totally different fueling and timing. Thus, the transition point on a speed density engine which runs off PSI-based mapping is very difficult to compensate.

WOT at 7000RPM for example, and the valve "opens" at a pre-determined amount of boost; but once the valve opens, additional fueling and different timing has to be implemented. When the valve opens, boost also drops because the engine is pulling more air but turbine speed is still trying to climb up.

Dual fuel/ign maps is required, and a PWM controlled circuit (to smoothen the transition); and lastly, do it in a fashion that it is quick enough in which you do not feel a "flat spot" when the turbine is trying to build full RPM's is VERY difficult.

The smaller the engine is, the wider this gap in tuning becomes. It may work decent on a Supra with a 71mm turbo, but will not even come close to working well on a 1.8L with a 67mm for example.

 

Ah.. the voice of reason. I hope it puts an end to this whole debacle.

 

I had originally planned to run a qsv. But after mocking up my turbo setup I realized that with my manifold and a qsv, the turbo would be too low for anything close to proper oil return. I'm glad I didn't figure out a way to make it work now, especially after reading Tony's post. I can see it being a tuner's worst nightmare, lol.

 

Awesome thanks for the info!

 

honest question, from someone who wants to learn more:

how about tuning in an alpha-n map?

 

Here's a comparison on a big turbo Supra.
http://www.supraforums.com/forum/sho...ck-Spool-Valve

 

BUT THAT IS A BIG SUPRA.. I've seen that comparison before. I'm not falling for it based on what I've experienced with it.

 

You dont need a spare pwm output, you can use an adjustable hobbs/boost switch & mac valve. Very simple & easy to do

Weve used them on multiple types of motors & they work awesome, yes some of them are supras also. Including my own 2j. As far as VE & tuning goes its not all that hard or bad. Most honda builds have,quite an affect & shift or alter or move the VE anyways with the large intake manifolds, cams, head porting & crank changes.

If the VE issue were such an issue we wouldnt be much using any sort of roots blower, or twin charging or turbos with 1.25+ backhousings.

Its not perfection but it does let you cheat the system a bit. for me it was no different then tuning say a small "volvo t3 .42/.48" type turbo in the low end. Boost came on extremely fast & then carried on like normal for the top end once the valve opened.

Imagine being able to use an S475 or S372 as if it,were a 62mm in terms of response?

Its quite fun

 

Mike, hook a brother up on a manifold re-fab so I can run the qsv and still have good oil return. And while you're at it, give my wg priority so the creep is no more and we can finally dial in the bbg! You charge hourly for something like this?

 

bring it over and I will knock it out, shouldnt take that much work. I can make that gate lead spread a little further across the collector and taper a downward angle.

we can trim the collector enough to use the QSV and sit the flange higher

 

how would this not F**K an engine up? i owuld think with the valve closed on a true twin scroll setup, NO exhaust from cylinders 1 & 3 or 2 & 4 could pass through the manifold and turbo or am i over thinking this?

 

In order for this setup to work, you cannot use a divided manifold. Only the turbo's turbine housing is divided. The manifold must be an open manifold.

 

Sounds like a plan! Are you stocking the qsvs now or do I need to order one? Also, in regards to the gate, do you keep some S10 pipe laying around? If needed, I have a small piece left over from shortening the wg feed and removing the 38mm flange in favor of the 44mm. And I'm assuming you tig it up pretty? Or am I gonna need to jump in there with a stiff brush to remove mig spatter and paint over the welds after lol!? <--- I don't mind doing this btw. Ha!

Basically, I need to have all my ducks in a row if I'm going to make the trip over to Mobile, give the car a chance to cool before we do work, knock everything out, and make it back home the same day.

Think it out thoroughly and shoot me a pm with what I need to provide and a ballpark price for your labor. Thanks, dude!

 

It doesnt say twin scroll its a divided turbine housing with an open manifold.

Bully dog has had this type of setup out for years with thier "fast spool" valve.

A stock supra acts in this fashion with its variable switching valves to close off a portion of the downpipe to manipulate the stock twins. Its nothing new just a different design. Its a mechanical VGT so to speak in crude terms.

i have straight and 90s in stock, stainless.

I have one more in stock but its spoken for with a deposit right now but can get them almost overnight.

 

PM me the ballpark figure, duderz. I have to prepare the wife for the financial damage that is to come. Ain't Skeered!

Also, are you able to pass on any savings on the qsv or is it all the same for me to place the order myself?

I'm ready to see this 60-1 pop off like a JRSC!

 

Mrbsponge, have you guys used a QSV on b series yet? I have t3 35r w/.82 a/r do you think the QSV will work for my application. I want to improve my midrange but don't want to spend $1700 on GTX3071r.

 

You have a t3 open housing. First you need a 1.06A/R housing first before doing that. Even still, it respond nothing like a GTX3071.

Lots of investment for little gain in a sub 3.0 little application