Have any of you heard about 'quick spool valves'?

[Tippy]

I stumbled on this tonight on the webs after riding in my friend's 750 hp S/C'd '06 Viper. After feeling the pull of that beast, I really wanted to achieve quicker spool since mine feels a little anemic now.

When I was searching the webs for a split-scroll housing for my Turbonetics turbo, I discovered 'quick spool valves' and how many have made huge gains regarding spool time creating higher tq/hp at low-RPM's dyno verified.

Essentially, it is a valve with a single butterfly that is attached between the turbo and the header or manifold which chokes off one side of the scroll decreasing A/R. Here is the catch; you have to have a split-scroll housing with an open-plenum header or manifold for it to work.

At low RPM's, the butterfly is in the closed position cutting the A/R down to roughly half! So, if you have an .84 A/R and the valve is closed, you now have a .42 A/R accelerating turbine speeds! Once you achieve a given boost level, the valve will open and give you roughly 95% of the original A/R. The reason of the ~5% loss is the butterfly and shaft taking up area.

I did a search here and found nothing....

I know these cars would gain tremendously from this valve. I would love to play with one.

Please discuss.

[911nut]

That is way cool.
How is the butterfly actuated? Electric or vacuum?
I wonder if there would any durability issues with the butterfly operation long-term in such a harsh environment?
It would be worth a try, despite any potential drawbacks.

[RarlyL8]

I researched that some time ago.
The theory is sound from what I can see, the most immediate problems are:
> The valve assembly is 3/4" thick and sits on top the T3 turbo flange on the headers. This would make the turbo sit 3/4" higher which we have no room for. Custom headers would be required.
> Longevity of the valve itself. These turbos glow red, how is that valve going to live in that environment long term? The proper valve/housing to do this right would cost huge money.
Having said that I do intend to try this out and will make a set of custom headers. The headers cannot be split plenum as mine are.
The valve is actuated by boost pressure.

[Tippy]

Originally Posted by 911nut

How is the butterfly actuated? Electric or vacuum?
I wonder if there would any durability issues with the butterfly operation long-term in such a harsh environment?
It would be worth a try, despite any potential drawbacks.

Boost I believe. You set it to the boost that you want it to transition to. I'm sure the butterfly will have to be changed regularly due to the environment.

Originally Posted by RarlyL8

Having said that I do intend to try this out and will make a set of custom headers.

Brian, I disregarded the first part of your message. This is all that matters.

[Tippy]

This is obviously geared for drag racing and but it may work on small tracks too if you could really dial in the right transition to fully open.

I read it is better than twin turbos.

That's a bold statement I read!

[Flieger]

So this is like a variable-vane turbo, then, but not as efficient.

[spence88mph]

Originally Posted by RarlyL8

> Longevity of the valve itself. These turbos glow red, how is that valve going to live in that environment long term? The proper valve/housing to do this right would cost huge money.

Would the enviroment be an better/worse than a turbo with an internal wastegate? Just askin...