So how long till someone stuffs one of these on a supra?

[destrux]

http://www.honeywellbooster.com/turbocast/vnt-dualboost-turbo/

I'm guessing we just have to wait for a few ford trucks to make it to the junk yard to make this turbo affordable.

Pretty damn cool though... similar to compound charging, but with one turbo. I'd love to see a 2000hp 2JZ running 100psi of boost with one of these under the hood.

 

[Turbo Habanero]

That's Amazing I wonder what kinda of manifolds will be needed

 

[destrux]

It still uses a single turbo manifold.

The turbine side uses VNT though, so it acts like a small turbo at low RPM/low boost (fast response) and like a big turbo at high RPM/high boost (high flow).

The really cool part is the two compressors stuck on one turbo...

See, what you can do with that is use both compressors inline to compress the same air twice to achieve really, really high boost pressure.

Here's an example with both compressors running at a 3:1 pressure ratio:

Intake air enters at 14psi absolute pressure (guessing at a ~0.7 psi drop from air filter), first compressor compresses it to 42psi absolute (27.3psi of boost "gauge pressure").

Pre-compressed air enters second compressor at 42psi absolute, and is compressed again at 3:1 ratio to 126psi absolute (111.3 psi of boost!).

My understanding is that it's much more efficient for two compressors to achieve 111.3 psi of boost in this way then it is for a single compressor to achieve it, because a single turbo would need to run an insane 9:1 pressure ratio to achieve the same thing.


This is all assuming someone could build an engine to handle that much air.

 

[the_shippey]

That's beautiful.

 

[fixitman04]

amazing.... makes me want a new truck

 

[IJ.]

Porsche have been doing VNT for awhile now

 

[GrimJack]

My concern with the Porsche units is that those guys are crazy - they are completely willing to replace a turbo every couple of years and consider it a wear item, like brake pads or clutch discs. I don't know if that's what is happening, I don't think they have enough road use on the VNT tech in a gasoline engine yet.

Furthermore, they are also willing to build their turbos out of exotic materials that would put it well outside the price range of ... well, of us. These are the guys who built a lithium ion car battery - that only works in the summer - and you can order one for your car if you're willing to pay the two thousand euros for it. Admittedly, it does save you 22 lbs, but that's still pretty damn pricey weight reduction.

 

[MPR]

Very cool. Saw this design a year ago or so... When you have two compressors feeding a consolidated outlet, this actually allows for more boost at lower turbo shaft speeds. This would significantly increase the longevity of the unit. And with the variable veins, the efficiency range is greatly increased.

I've toyed with the idea of a turbocharger design with an axial pre-compressor (like in a jet engine) to pre-compress the air before it is then compressed more by the centrifugal compressor... I even did a crazy design for ridiculous boost pressures with an axial turbine after the main turbine with variable veins to further scavenge energy from the exhaust gases... Here's a little drawing I did in autocad for fun one day:

The turbo shaft extends out past the down pipe for another concept idea which was to make further capture and re-use the exhaust gas energy by either driving a specially designed alternator or mechanically linked back to the crankshaft (already in use by Volvo and Detroit Diesel in highway tractors).

Turbochargers are one of the best inventions of the last century. Seeing how many vehicles are now available with turbos from the show-room, I think we're only going to see more and more as time goes on and the technology further evolves. I've also seen some companies working on developing turbochargers with integrated electric motors/alternators, which will help extend the efficiency range, reduce lag and relieve the load on the vehicles main alternator when the turbo is working.

Great post. Love this stuff!

 

[SupraPieces]

Fantastic find De... will be searching the junk yards for late model pickups with the turbo engine now...

 

[te72]

Correct me if I'm mistaken, but hasn't GM been doing VNT turbos for a while on their Duramax engines? Granted, that's diesel, and like Grim said, it's not very common on gas engines yet...

What about Limequat on here? He's got himself a VNT turbo from a Duramax on his 4.2...

 

[GrimJack]

VNT on diesel engines has been done many times by now. The thing is, EGTs on diesel are significantly lower than gasoline engines, so it's much easier to build something that doesn't fuse into a solid chunk of steel on a diesel.

 

[te72]

The thing is, EGTs on diesel are significantly lower than gasoline engines, so it's much easier to build something that doesn't fuse into a solid chunk of steel on a diesel.

Are you referring to the vanes on the turbine itself? Those always seemed rather flimsy to me...

 

[IJ.]

Are you referring to the vanes on the turbine itself? Those always seemed rather flimsy to me...

VNT uses moveable vanes in the turbine housing to do much the same as putting your thumb over a hose.

 

[Albert]

Local guy did it. It's been done.

 

[destrux]

The VNT isn't the exciting new thing here. It's the fact that the turbo has TWO compressor housings and TWO compressor wheels and can compress the same air twice using one turbocharger unit.

The VNT is just the icing on the cake.

 

[Albert]

Eh still. Being a Honeywell supplier for 25+ years and weve seen this type of technology used many different times in different applications, they're just now adapting old technology into a new application. Idk guess it doesn't phase me as much lol

 

[destrux]

I see. It's new to me

 

[suprajztwenty]

im pretty sure the new dodge runs a twin compressor wheel now too. i saw one at tx state fair...it was a cutaway so the compressor housing may have been different but it looked like a single out, not like this dual one.

cool shit tho, id still be plenty happy with just a plain bb vnt on my 7m.

 

[Skeezix]

Yeah VNT is definitely not the new part, Dodge did it in the late 80's early 90's with their small cars

 

[MPR]

I think some of you are confused. The Ford turbo does not compress the air twice, it just has two compressors (one compressor wheel with back to back blades, basically a two-sided compressor wheel) driven by one turbine. It has a single charge pipe outlet. The oval shaped opening at the top is to feed air to rear-side compressor blades.

The variable veins help spool the turbo shaft with the extra mass of the extra compressor blades quicker and sooner. Having two compressors allows the turbo to flow a lot more air at lower turbo shaft speeds compared to a single compressor turbo with one set of compressor blades having to do all the work. But it does not compress the same air twice (one compressor does not feed the other). Both compressors feed the same compressor housing/charge pipe outlet at the same time.

What is odd is that they advertise the waste gate like it's an innovation when virtually all turbos have some kind of waste gate.

Some early jet engines used this dual-sided compressor design way back in the 40's and 50's. Some jet and turbo-shaft engines, I think, still use this design to a certain extent. So it really is nothing new at all. Like Albert said, it's an old design integrated into a new application.

Seems to work well in a turbocharger application though. We may see this pop up more and more in future turbo designs, although the extra cost may hinder that.