If two turbos, say stock vs a 3037, are both putting out 20psi, will they both have the same hp limits? I would generally think so, but I see people claiming higher than stock turbo hp numbers at the same psi..

This is assuming that all things are the same except the actual turbo..

Terry S

 

The 3037 will deliver 20lbs of much cooler air than the 16g which is much better for combustion.

 

Interesting.. Is that because the compressor housing is larger?

 

Boost Pressure is just part of the equation..

Its just one factor in how much air goes into the engine (Density/Volume)

Bigger turbos at the same boost pressure, can move more air at the same pressure.. given neither has other restrictions, it will result in the larger turbo able to more more air volume (CFM)

Then there is the density aspect of it.. the density of the air is a factor of temperature, and pressure. the bigger turbos usually result in higher pressures because they can move more air, but since then you hit restrictions again (intake manifold, throttle body, etc)..

Think about it this way...

you can blow into a straw and produce a certain amount of air pressure, but if you blew through the same length of hose, you'd likely run out of breath before you built up the same pressure.. the restrictions generate heat also..

Sorry, I tried to keep this pretty basic..

 

Well, yeah...but no.

You have to understand that is you move X amount of air compressed into a tube at 20 PSI and move 2x that amount of air at 15 PSI, whats going to make more power? PSI isn't the tell all of horsepower, the CFM of a specific turbo will determine its power output. THats why if you get yourself a 3037S and turn up the boost to 21 psi on a stock motor with no management or fuel system upgrade, you'll $hit the pistons out of the oil pan instead of posting big numbers.

 

MJ, I was saying "no" to the first response, just to clarify.

 

The 3037 will be more Efficient, resulting in a much steady cooler air flow

 

Ultimately the process generates less heat with a bigger turbo, resulting in denser air.. if you measure pressure at different locations in your intake tract (before and after the intercooler, before and after the throttlebody, you'd be very surprised at the variations you'd see)

 

LOL I figured..

 

Ok I think i'm getting it, but there's a bottleneck in my understanding of this I think..

So a larger turbo is able to put out more air at the same psi as a smaller one. In addition, the temperature will be lower so the density will be more.

However, this is all before the IC piping size, IC, throttle body, and intake manifold which has set diameters that at a given psi and temperature hold so much air..

So if the density is higher from the lower temps, then the main benefit of a larger turbo putting out the same psi will be lower air temps (therefore more density) right as it goes into the cylinders?

(A still confused) Terry S

 

Fair enough, but the main source of power increase isn't going to come from just cooler/denser air.

 

also more VOLUME of air at the same pressure..

 

If the 3037 provides a Backpressure reduction between the turbo & the exhaust valve ( which I believe it should); a turbo with a larger turbine housing & or more efficient turbine wheel, you'll make more power. This is due to less "spent exhaust" from camshaft overlap, re-entering the cylinder & contaminating the next firing event of that cylinder.

Increased backpressure creates heat, which in turn heats up the compressor side too, thus heating the air entering your intercooler. Cooler air is denser. If the air is cooler entering the ic, it will most likely be cooler coming out, as long as its not 20f outside or something that extreme.