welcome, that’s still a damn good price for an A4
yeah man im not complaining
This is a fallacy.
The amount of power you make is directly proportional to the amount of fuel you are burning.
You cannot burn more fuel without more air. This is where the entire concept of A/F ratios and wide bands comes from.
Your engine has a constant volume. Without boring or stroking the engine it is impossible to make more power without increasing the pressure. (assuming afr, Ev and timing are optimal)
Therefore you will not be “flowing more at lower boost” since this is physically impossible.
As for your concerns about the lifespan of a K03 under high pressure, they are probably warranted. There is only so much you can do with a turbo the size of a walnut.
I will however point point out that the axial load on a turbocharger is proportional to the ratio of pressure/flow * pressure, so stating that more pressure is damaging the turbocharger is sort of true but not really.
There are two primary sources of axial load in a turbocharger.
- The turbine wheel.
Any swept blade turbine wheel has both an axial and a tangential force component. The ratio of these components is proportional to the blade angle, which is a complex curve requiring gradient analysis. This is Calc 3 and a bit out of my comfort zone.
However logically it is easy to see. as the turbine wheel extracts power from the exhaust, it is providing torque to the compressor wheel. The more torque the compressor wheel requires, the more axial force is created. This force pulls the shaft tword the turbine end of the turbo.
- The compressor wheel.
Obviously there is pressure on top of the compressor wheel. The maximum pressure is proportional to the cube of the tip velocity. The velocity gradient is proportional to the maximum pressure, the velocity distribution, and the wheel area. None of these are linear terms. All of this pushes the shaft in the same direction is the turbine load. They are additive, they do NOT cancel each other.
Now if you have ever looked at a turbo you will notice there is an annular gap between the compressor wheel and the diffuser plate. You will also note that the wheel is lower than the diffuser plate. The is ring feeds a stagnant volume of air which is trapped behind the compressor wheel, which DOES act in the opposite direction of the two other loads, and this attempts to reduce the axial load to zero. The compressor blade geometry also has a load reducing screw effect but this is negligible.
This is why a Garrett GT turbine wheel has a significantly steeper blade angle, creating higher performance and greater axial loads. A fluid thrust bearing cannot handle these loads with standard oiling pressure. Therefore the ball bearing technology was employed to carry the additional loads created by the advanced turbine wheel geometry.
GT turbine wheels = rolling element bearings.
T turbine wheels = fluid bearings
no. those surge badly. the compressor wheel/turbine are very mismatched, especially on a 1.8t
Well thanks for the info… my main concern was blowing that k03 under that amount of PSI to acheive the numbers i would like to see
so following your wizardy. you are saying my GT3071R is not making more power at 15psi than a k03 would make at 25psi??
i will gladly do a side by side dyno of a full bolt on k03 car vs my car at 15psi
see that was what i was org. thinking that a bigger turbo on lower boost would produce more hp than a much smaller turbo maxed out… idk to much but thats what i thought
its all about volumetric efficiency and CFM. luckily youve got an AEB head already… a k03 is not efficient at higher boost levels, they just make loads of torque, and lots of hot air.
but this guy is an engineering student or something, with a stock car so trust what he says.
:rofl
And who are you?
What do you know of turbos?
MK is GOD
what is a turbo?
:rofl
Some good turbo info in here tho!
Sir stop acting like you know about audi/vw’s and turbos…:shifty
but i really dont know anything. i just read alot of superstreet and import tuners.
thats how its done…
You do not understand the difference between flow, and mass flow.
If you were to hook up your manifold to a pressure regulator with unlimited flow, your Hp would be directly proportional to pressure. This is all i am saying.
All of your turbo statements have a lot more involved than just pressure. Obviously bigger turbos make more power.
other variables you are not accounting for.
-heat
-the area under pressure vs flow graph
-back pressure
-turbine acceleration
-compressor maps
-turbine efficiency
-windage losses
It is the combination of those 7 things and more that make your engine perform better than a K03 car.
whew… its getting hot in here!
:ninja