There is a Subaru up this way thats running 2 turbos and uses compound charging All very interesting

 

Subaru running it? Ive seen twin turbo legacys etc that the writeups about them claim its a staged setup like this, but its not at all, its a sequential setup, ie the turbos DONT blow thru each other.

If its really compouund charging this scooby id love to know more...

 

Steve, years back I was talking to Geoff Kershaw (MD of Turbo Technics), and he told me that he was working on a "twin" turbo set-up called "K Gate".....

Cannot recall how it was done, but he drew out a letter "K" as proceeded to explain how one turbo was linked to the other to produce a combined out greater than both turbo's could produce if linked in any other way........went waaaay over my head THB....wonder if it was the same thing as in your pics ???

 

Oh right... I didn't know that Steve - I always thought that, say on a Supra TT, the little turbo spooled up first and in turn it spooled up the bigger turbo?

Or is it just a case of the little one spools up first (cos it's smaller) and the bigger ones spools up later (cos it's bigger) but it just uses normal ambient air like the little one does?

spose that explains why you see Skylines and Supra's with twin button filters - D'OH!!!

So the "sequential" bit is just cos the spool up in sequence?

Think I got it now Staged or "compound" turbo charging is using one turbo to spool another and so on...... Interesting...

 

Id love to say more however its not my place!

 

Doug- Nope, thats a sequential type setup they designed for cossies years back, IIRC Tony@Turbosystems still has the bits to use it.

Basicly was a twin sequential setup running like a T25 and a T4, the gate put all ex gas to the T25 till a certain pressure then an actuator type thing moved the gate to bring the T4 into play

IIRC it worked, but the price and room it takes up outweighed the advantages it gave.

Thats the thing see, there sooo many examples of sequential type setups around, inc some that share all the ex gas like the staged turbos do, but NO detailed info on setups where turbos blow thru each other.

Basiclly what i posted is a common mod on modified Cummins Diesels that often run 100psi+ boost, twin and tripple setups
But info on exactly how it works on the net? Feck all

 

Looks awsome!


Prob some mental thinks out there with different combinations of turbos that have been tried by some nutty professors

 

They work in various ways, either the simple- 1 small 1 big one, so one boosts from the start and the bigger one comes on later for a boost, or more complicated ones (kinda like the K gate doug mentioned) where all gas is given to the small one and then using a pressure (or whatever) operated valve the gas is also given to the bigger one.
Dont forget, the smaller turbo on sequential setups dont feed the bigger turbo boost, its the exhaust gas created by the power and higher RPM that spools the 2nd one up

Well yea, they both share the same exhaust gas like sequential setups (unlike twin turbo setups who split the ex gas equally between the 2 turbos), but staged ones also use turbos blowing thru turbos which seems to enable incredibly high boost pressures

Interesting, but no details yet, there is meant to be details of the setup in some turbo books, but i aint got em

 

I can see how the turbo blowing into turbo will allow stupidly high boost pressures, as like rob said, the second turbo is already get fed compressed (or "charged") air so the flow and boost characteristics change...

 

there's not much info on the interwebthingamujig cos the farmers who build 'em don't have them new fangled puters.