HyperactiveSloth

If I could answer you by rewording what you said...I am looking for an engine to build a turbo for which incorporates "wheels" I have designed.
I am trying to make as little of this kit from scratch as possible, except for the turbine/compressor. That's why I was mainly asking what turbo trims/assemblies would be easiest to modify to replace the internals.
My other question was what the approximate ratio of (turbine input)/(compressor output) is for most turbochargers. I know it's a little different for different engines, but even an approximate (or if you know the specifics for an engine you reccomend [i think I like the DSM suggestion] or for my engine [see below] ) would allow me to get a head start on part of total design.

:below:[I have a GA16DE that I was thinking of using, but then I wasn't going to use it because from what I've found there aren't really any turbos out there for it, which would make things harder, and because if I did boost it it would only be a few psi or else quickly wear out the engine (it's got over 300,000 miles). If you think I could do it with this engine, though, my ears are open for info.]

So, basically,
What existing turbos would it be easiest to replace the internals?
(subquestionoes ^that^ turbo come stock on a certain engine or get commonly used on a certain engine?)

What is the average ratio of (pressure to turbine)/(pressure from compressor) or maybe (volume through turbine)/volume through compressor) in most turbos?

norbi

your idea is the crazies I have heard about.
I doubt there is average ratio of turbine/compressor flow rate because as I understand this is what you are reffering to.
here http://www.turbobygarrett.com/turbob...ochargers.html you can find a lot of maps of compressors and turbines, but you change the housing and the graph is totaly different. Basically here you can see how graph change for different A/Rs
I'll put it this way, let's assume you have your design wheels made and they are fine, you put it into center cestion of any other turbo and the hot and cold side housings. Then you need to check what real is the flow of your turbine and only them you can figure out what engine this "custom" turbo will be good for.
Unles I have mixed something or missunderstood whot you want to do.

Obscene_CNN

If you wondering what type of turbo to base things on I would go with a T3 since they are used in about everything and you can get all sorts of housings for both the compressor and the turbine.

The pressure ratio of a turbine over the compressor is based entirely on the efficiency of the turbine and compressor at a given flow rate. The more efficient each the lower the pressure ratio. Commercial turbos usually run about a 2 to 1 ratio.

HyperactiveSloth

OK, slightly different question then. What is the common range of volume in to volume out ratios between intake to exhaust. In other words what do you get when you divide the (volume of exhaust) from the engine by the (volume of intake) at normal air to fuel ratios?
I know things like intake air temperature, engine operating temperature, and other combustion variables have an effect on the answer to that (even within a specific engine) so that's why I asked for a "range" rather than a magic number.

on the average...
min. [(exhaust volume) / (intake volume)] --- max. [(exhaust volume) / (intake volume)] = ?-?

Thanks if you can give me some help on this or even direct me to some data.

Oh, and thanks Obscene_CNN for humoring me.

bcohen5055

I really know nothing about all this technical mumbo jumbo at all but I would say that a turbocharger is a force transformer (wheel and axle) first you need to know the desired flow rate of air at a specific rpm on the output side of the turbo then you need to find what the flow rate of the engine exhaust is at that same RPM. Once you know this information devide output over input to find the size ratio of the 2 sides. However because flow rate is not liniar I am guessing that the desired RPM would prity much have to be your redline and untill you hit that point urr gonna have a bunch of lag. But I really have no clue about anything. Good luck this should be "interesting"

Obscene_CNN

More humor

Volume of exhaust = (displacement * rpm)/2 (assuming no blow down)

But seriously....

You can't use volume as a measurment because pressure varries based on load. This is also why compressor maps use mass flow. You need to look at enthalpy of the exhaust gasses and that depends on your engine and fuel ratio.

HyperactiveSloth

OK, so how do I find out the mass flow of an engine without buying it and testing it?¿?

any suggestions?

fork

there are easy to find mass flow formulas for engines based on rpm and displacement. also you can find the volume of the air coming in and going out by siple thermo dynamic formulas. remember the mass of the air going in is the same as the mass of the air goin out. so use the mass flow formula that can be found in a sticky thread on top of this forum section, the you can estimate the the temperature of the exhaust because you know the range it will be in and by the mass and the temperature you can get the volume and get your volume in/out ratio.

now how do you plan on producing a turbine wheel.

HyperactiveSloth

FINALLY, a straight forward answer!

Unfortunately, I'm not going to give you one. :P
Life's a bitch, huh? AHAHAHAHAHAHA *ahem* I'll post more tommorrow, I'm tired.

HyperactiveSloth

I'm going to make the turbo from one of my existing designs of bladeless turbine.

I need to calculate mass flow and pressure to determine the appropriate diameter of turbine and number of flow paths. From there I'll need to do testing of the installed application and adjust for variations between estimated efficiency and actual efficiency.

So far my only tests and data have been from "cold" testing. I figured a turbo would be the perfect way to test my designs under constantly varying heat and pressure conditions. It's the "hot side" that interests me most, but while I'm at it I plan on testing with both centrifugal compressor and BT versions on the "cold side", and comparing their performance.