hokiruu

iTrader: (19)

LOL. Ford is pretty proud of their Twin turbo setup, and lots of people hear that "even the turbocharger has a turbocharger" and are all blown away by the sound of it. All it means is that, like other said, essentially there are two turbos, one for lower powerband to provide boost where the bigger one would be lagging, and the big one to provide boost where the smaller one would out of it's efficiency range, and just as a single engine and turbo have a symbiosis is powering each other, these turbos do the same for each other.

FullOutPwr

iTrader: (12)

Pics aren't needed to explain... just think of the discharge on one turbo going to the inlet of another turbo. Its very common on sled pullers and those running p-pumped rigs. Best of both worlds... little to no lag and big turbo power. GT38 was a ***** to spool on the older powerstrokes like mine.

Nj3000GT

iTrader: (1)

i believe its called a compound twin turbo setup, its a smaller turbo, that feeds to the inlet of a larger turbo and then from the later turbos outlet to the engine.

UT_Evo

iTrader: (5)

Isn't it the F1 cars that have a Supercharger/Turbo system similar to this?

Tek3Evo

iTrader: (11)

Why wouldn't that overrun the smaller turbos compressor and cause issues once the larger turbo starts sucking harder than the smaller one can provide air?

Tek3Evo

iTrader: (11)

^nevermind, I found a good link for it.

http://www.atsdiesel.com/ATSWebsite/HIWCompounds.asp

RoadSpike

iTrader: (5)

That would be correct becuase compound turbo charging is done the opposite way with a larger turbo putting air into the smaller one. The general idea behind compound turbo charging is very simple. Basically your turbo is a air pressure multiplier usually with a range of something between 2.5 atmosphere up to 4 bar in some racing turbos. So lets stick with something simple for a demo.


Simple math:

Lets say the big turbo flows a max of 3 bar of boost into the small turbo which can flow also 3 bar of boost max. So the 3 bar of boost is boosted 3X to 9bar of boost or 130 psi if you were to let it reach that insane pressure.

Corey

iTrader: (10)

I work at the Super Duty plant and build them. Like other people have stated, the smaller turbo is basically there to spool the bigger turbo. I was told that the smaller turbo is almost at full boost off of idle. With the new 6.4, they aren't using Garret turbos anymore and switched to Borge Warner turbos.

I have the luxury of looking at these big turbos on a nightly basis cause I work right where the engine is placed on the chassis. The guy one job down installs the down pipe.

When we wre told the 08's were gonna be turbo, everyone thought it was gonna be a true twin turbo with a turbo on each manifold.

20Grockit

iTrader: (10)

thats a ridiculously crazy lookin setup. i wonder how well it works tho.

hokiruu

iTrader: (19)

That would rule! too bad it's not.

andrew_sup

iTrader: (194)

i wonder if it's possible to use 3 turbos on that or bigger motor. lol

Forrest Gump 9

iTrader: (19)

This man got it right. They are called compound. The smaller turbo feed into the big turbo to compound the boost. This system is the design so that the truck can run an outragous amount of boost (60+psi).

5psi from the small turbo feed into the big turbo and BAM, 25 psi total.

MaelstroM

isnt this similar to bmw's twin turbo diesel engine on their 530d?

Autoilluminate

iTrader: (1)

tractors have been doing compounding turbos for ages. Superstock tractors can run up to 4 turbos and 250 psi of boost. Compounding creates alot of boost and also creates heat, but diesel engines like heat (to an extent)

See picture below. There a 3 LARGE turbos on this tractor. The 2 shown feed another larger one which is hidden behind.



Edited image

Tek3Evo

iTrader: (11)

Have gas engine ever done this to a smaller extent to allow for more boost with little to no lag? I realize that when talking huge boost you have huge heat, but if we compound turbos to get 30-40 psi simply to have boost off idle, I think this would be a great advantage.