wgingg

im trying to figure out how the twins work. i was a heavy equipment mech so i know the basics of a turbo but for the life of me i cant figure how you make the second turbo spool up when you lose heat and velocity after the first one? every thing i look up about them doesnt explain this so i though this would be a good thread.

gunracer1

go to piers website and take a look at the picture of the blue and black twin turboed 12v. look under turbos then twin turbos. that is the best pic i have found when trying to show some one. it is hard to explaine it but the pic always brings them around.

RowJ

What you may be missing is what some call the "reverse flow" on twins.
Exhaust gas is always expanding...engine to small turbo...to big turbo...to exhaust pipe.
Compressed air is always compressing....Air Filter...to big turbo...to small turbo...to engine.

Hope this helps?
RJ

gunracer1

i look at that pic and wonder how they will attach a airfilter. the piers site has a better pic, the motor is not in a truck.

MCummings

Very Carefully

Merrick

wgingg

guess ill have to see it some day to fully understand thanks guys

got...DIESEL?

Maybe this will help some folks more than others..........click to enlarge

DZLPWR

Great diagram on set-up. I dont understand the whole boost doubling idea? How can the incoming air from the big turbo get past the smaller turbo without over spooling it? I mean, it obviously works well, just cant quite grasp the theory. Thanks -Jake

RowJ

I'm probably the wrong one to be explaining this...because it is kind of counter intuitive to me also!

The second turbo takes what it gets and increases it by say 25 psi. If it gets already compressed air (this is the cool air side we are speaking of) it does the same thing.

Feed the small (second) turbo X amount of air and it compresses it times 5 (just as an example). Feed it 3X amount of air and it compresses THAT amount of air 5 times!

Remember, the cool air from the big turbo (#1) is not driving the small turbo compressor....the hot side turbine and shaft are what drives the cool side compressor fan.

I wanted to try and answer this to see if I understood it well enough to write a reasonable explanation. Fairly happy with my asnwer but am sure someone else can do it simplier and better!

RJ

wannadiesel

I think you did just fine.

wgingg

ok i get that part, its like a 2 stage air compressor. or i should say it is its the exhaust side that befuddles me. i guess i just dont understand how it cools off and expands at the same time? (between the 2 turbos)

1dslram

The exhaust doesn't cool and expand between the turbo's, that is the reason the pipe between the turbo's is always wrapped to maintain the heat and reduce cooling.
Bruce

DZLPWR

OHHH okay. So the small turbo is building off of what the big turbo is pushing to it. So small turbo thinks its pulling ambient air, but its acually pressurized, so it just builds more on top of what the bigger is pushing?

signature600

By George, I think He's Got it!

As I understand it, that's how it works.

Chris

SmokinFive9 4x4

Not to add to any confusion, but how does this reduce EGT's? wouldn't it raise them a little because of the added backpressure from a second turbo?