Boost Calculations
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From: Ballard, WA
Boost Calculations
Does anyone know a place to find some boost calculations? Im in the process of moving, and packed all my books. Im referring to the formulas to calculate power output based on boost/CR/fuel air, etc.
I had another question too...maybe I'll remember what it was later.
Oh yeah I remember...
Has anyone here ever done anything with turbochargers run in series? I have read about it done, and seen it once on a tractor, but I cant find anywhere that explains how it works, or how to determine any values.
I had another question too...maybe I'll remember what it was later.
Oh yeah I remember...
Has anyone here ever done anything with turbochargers run in series? I have read about it done, and seen it once on a tractor, but I cant find anywhere that explains how it works, or how to determine any values.
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From: Heart of Dixie
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From: P-Town, CA
Inline turbos work is that the 1st one is smaller, spools up faster for instant power, and at the point where its reached its peak, the larger one is already spooling up. The only thing i dont understand about these is that, is there a bypass so once the 1st is maxed out, it doesnt slow down airflow for the seccond
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From: Ballard, WA
Hey '9
Thanks for the reply...
I believe what you describe are the systems like older Ferrari's use (could be wrong on that, because Im not old
). I thought I had remembered that those use the small turbo to spin up the larger one (because I remember thinking that would be a heat transfer disaster). If the case was that they used two seperatly sized ones, it would be possible to set up one small one to spin fast, and a larger for more boost, but you would not have equal flow between your two exhaust outlets, and possibly unequal boost to each side of your manifold.
What I was curious about is putting them in a line, a big one followed by a small one. People have told me (perhaps believing me gullible) that the boost can actually be compounded into the 60-70 psi range.
Other than that, I'll either eventually figure it out, or destroy my garage trying.
Thanks for the reply...
I believe what you describe are the systems like older Ferrari's use (could be wrong on that, because Im not old
). I thought I had remembered that those use the small turbo to spin up the larger one (because I remember thinking that would be a heat transfer disaster). If the case was that they used two seperatly sized ones, it would be possible to set up one small one to spin fast, and a larger for more boost, but you would not have equal flow between your two exhaust outlets, and possibly unequal boost to each side of your manifold.What I was curious about is putting them in a line, a big one followed by a small one. People have told me (perhaps believing me gullible) that the boost can actually be compounded into the 60-70 psi range.
Other than that, I'll either eventually figure it out, or destroy my garage trying.
Last edited by PyroBob; Mar 6, 2005 at 06:20 PM.
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From: Destin/Ft. Walton Beach,
With that much boost, you would have to have a very low static compression ratio. If not, you'll burn holes in your pistons, and have a very tough time to arrive at a livable air/fuel ratio. The only way it'll work, is with the small turbo first, and the large turbo being blown into by the large, and some type of system to cool the boost, along with a good fuel management unit.
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Post Fiend
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The boost is compounded, you are correct. From what I can tell, the normal mode of in-series turbos is to open a "pipe" that runs a bypass in parallel with the smaller turbo so that more exhaust flow can reach the larger turbo. Some of the exhaust will go through this tube, some will go through the first turbo. This way the smaller turbo doesn't get completely bypassed and slow way down.
Though I'd imagine that's a real pain in the **** to fabricate. But I've seen cast iron exhaust bypass valves at places like JC Whitney, that *maybe* interesting to play with if you really want this kind of setup.
Personally, I'd rather use one huge turbo, or two smaller turbos as it's much easier to fabricate such in your garage.
Vrooooooom.
Though I'd imagine that's a real pain in the **** to fabricate. But I've seen cast iron exhaust bypass valves at places like JC Whitney, that *maybe* interesting to play with if you really want this kind of setup.
Personally, I'd rather use one huge turbo, or two smaller turbos as it's much easier to fabricate such in your garage.
Vrooooooom.
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