flow rate

How many lbs/min will a ported TD05H 16g flow?

Guess.... 35lb/min max

Thats what I was thinking also

shape recorded 42lbs with an evo 3 and all the supporting mods

I found this last night on www.fivezeroseven.com (for those of you that live in southern minnesota) and I though it was pretty interesteng so I'm going to share. I think there were supposed to be some pics but there were none


Selecting a turbo size to match your engine is not at all difficult. You need to find a few things about your engine, decide how much boost you want to use, and then plot the information against a turbocharger’s compressor map. There is a little bit of math involved, but it’s easy.

First you need to know the CFM of your engine when running naturally aspirated. You can find this by using the following formula:

volume of air (cfm) = (engine rpm x engine cid) / 3456

So, an LS1 would look like this:

volume of air (cfm) = 6000 x 346 = 2076000 / 3456 = 600.694

The LS1 needs about 600cfm of air at 6000 RPM naturally aspirated. Now we know our NA cfm requirements, but in order to read a compressor map we’ll need to figure out the airflow in pounds per minute (lb/min) required by our engine under boost. For our example, let’s use a boost pressure of 10psi.

At this point it is important to talk about the difference between absolute pressure (psia) and gauge pressure. The boost level that you read on your boost gauge is really called psig or pounds per square inch gauge. The absolute pressure is 14.7 + psig. The 14.7 comes from the pressure of air at sea level. So 10psig = 24.7psia.

We can find our engine’s requirements by plugging our numbers into the ideal gas law. The ideal gas law relates volume, pressure, temperature and mass of air. It is:

PV = nRT

Where P = absolute pressure, V = volume cfm, n relates to mass, R is a constant and T is the air temperature in Rankine.

Let’s simplify the ideal gas law to find our engine’s required airflow in lb/min with 10psi boost. We will need to know the temperature of the compressed air coming out of the turbo. Let's assume an intercooled intake air temperature of about 130F. Turbo cars that do not have an intercooler can see intake air temperatures around 250F. To get the temperature in Rankine, simply add 460 to the air temperature in F.

n(lb/min) = ((14.7 + psig) x V cfm x 29) / (10.73 x T deg R)

n(lb/min) = ((14.7 + 10) x 600.694 x 29) / (10.73 x (130 + 460)R) = (24.7 x 600.694 x 29) / (10.73 x 590R) = 430277.1122 / 6330.7 = 67.96lb/min


We find that ideally, our LS1 will require 67.96lb/min of air under 10psi boost at 6000RPM. I say ideally because that assumes our engine has a volumetric efficiency of 100%. We’ll assume that our engines have a volumetric efficiency of about 85%. Now we can correct our airflow.

67.96 x .85 = 57.77lb/min

By the way, as a rule of thumb, horsepower can be found by the following:

Hp = airflow lb/min x 10 = 57.77 x 10 = 577.7

Now that we know our required airflow in lb/min, we need to find something called a pressure ratio. This is the ratio between the inlet and outlet pressure of the turbo’s compressor. Inlet pressure is usually 14.7psi. (standard barometric pressure at sea level) The outlet pressure is 14.7psi + boost pressure. Take the ratio of the two and you get:

Pressure Ratio = 14.7 + boost / 14.7

We decided to run our project at 10psig. That gives us:

Pressure Ratio = 14.7 + 10 / 14.7 = 24.7 /14.7 = 1.68

We now have all the of the information that we need to read a compressor map. Let’s take a glance at a few and see what compressor will work best with our application.

The maps show both efficiency and RPM curves for the compressor.
In order to read the maps, simply find the pressure ratio on the y-axis and follow the map over to where the airflow meets the engine airflow.



The map above is for a Garret T04E compressor in 60 trim. Notice the islands on the graph that look like ripples on water. Those are efficiency islands. It is desirable to have our point plotted right in the middle of the graph, although anything down to about 60% efficiency will work. Notice that our point is way off the map for this turbo. The turbo will still make boost, but will not be efficient. This is a bad selection for our project.

Our point is off the map to the right. What if our point fell in the surge limit area to the left? That would be very bad. In fact, it would surely cause damage to the compressor. In this area, the air flow is unpredictable and changes direction.

Let’s look at another turbo compressor map.



This is a map from a T76 compressor. Notice that the point lands right in the 70% efficiency island. This would be a perfect turbo for this setup.

It depends a lot on what 16g you have... Small, Big, Evo? They all flow different. Basically from about 32-42lbs. I've logged numorous 40-41lb/min pulls. Couple that got to 44lbs but I have a feeling that was compressor surge cause I was running 28psi on it. Way over efficiency.

I have a ported TDO5H which is a jdm galant turbo I belieze scottsee said its about the same size as a small 16g

Well. All JDM Syclone 4g63's came with a small 16g, not just specificly a galant. Just so happend to be the part # from the galant.

TDO5H small 16G flows 35.7 lbs/min stock, so I'm not sure how much more it will flow ported, I'm guessing maybe another 1-2 lbs/min. So you're probably looking at about 36.7-37.7, maybe. Scottsee was pretty much correct though, I just like to be more precise. :p

shape recorded 42lbs with an evo 3 and all the supporting mods

Actually Shape pulled 44lbs. :)

I found this last night on www.fivezeroseven.com (for those of you that live in southern minnesota) and I though it was pretty interesteng so I'm going to share. I think there were supposed to be some pics but there were none


Selecting a turbo size to match your engine is not at all difficult. You need to find a few things about your engine, decide how much boost you want to use, and then plot the information against a turbocharger’s compressor map. There is a little bit of math involved, but it’s easy.

First you need to know the CFM of your engine when running naturally aspirated. You can find this by using the following formula:

volume of air (cfm) = (engine rpm x engine cid) / 3456

So, an LS1 would look like this:

volume of air (cfm) = 6000 x 346 = 2076000 / 3456 = 600.694

The LS1 needs about 600cfm of air at 6000 RPM naturally aspirated. Now we know our NA cfm requirements, but in order to read a compressor map we’ll need to figure out the airflow in pounds per minute (lb/min) required by our engine under boost. For our example, let’s use a boost pressure of 10psi.

At this point it is important to talk about the difference between absolute pressure (psia) and gauge pressure. The boost level that you read on your boost gauge is really called psig or pounds per square inch gauge. The absolute pressure is 14.7 + psig. The 14.7 comes from the pressure of air at sea level. So 10psig = 24.7psia.

We can find our engine’s requirements by plugging our numbers into the ideal gas law. The ideal gas law relates volume, pressure, temperature and mass of air. It is:

PV = nRT

Where P = absolute pressure, V = volume cfm, n relates to mass, R is a constant and T is the air temperature in Rankine.

Let’s simplify the ideal gas law to find our engine’s required airflow in lb/min with 10psi boost. We will need to know the temperature of the compressed air coming out of the turbo. Let's assume an intercooled intake air temperature of about 130F. Turbo cars that do not have an intercooler can see intake air temperatures around 250F. To get the temperature in Rankine, simply add 460 to the air temperature in F.

n(lb/min) = ((14.7 + psig) x V cfm x 29) / (10.73 x T deg R)

n(lb/min) = ((14.7 + 10) x 600.694 x 29) / (10.73 x (130 + 460)R) = (24.7 x 600.694 x 29) / (10.73 x 590R) = 430277.1122 / 6330.7 = 67.96lb/min


We find that ideally, our LS1 will require 67.96lb/min of air under 10psi boost at 6000RPM. I say ideally because that assumes our engine has a volumetric efficiency of 100%. We’ll assume that our engines have a volumetric efficiency of about 85%. Now we can correct our airflow.

67.96 x .85 = 57.77lb/min

By the way, as a rule of thumb, horsepower can be found by the following:

Hp = airflow lb/min x 10 = 57.77 x 10 = 577.7

Now that we know our required airflow in lb/min, we need to find something called a pressure ratio. This is the ratio between the inlet and outlet pressure of the turbo’s compressor. Inlet pressure is usually 14.7psi. (standard barometric pressure at sea level) The outlet pressure is 14.7psi + boost pressure. Take the ratio of the two and you get:

Pressure Ratio = 14.7 + boost / 14.7

We decided to run our project at 10psig. That gives us:

Pressure Ratio = 14.7 + 10 / 14.7 = 24.7 /14.7 = 1.68

We now have all the of the information that we need to read a compressor map. Let’s take a glance at a few and see what compressor will work best with our application.

The maps show both efficiency and RPM curves for the compressor.
In order to read the maps, simply find the pressure ratio on the y-axis and follow the map over to where the airflow meets the engine airflow.



The map above is for a Garret T04E compressor in 60 trim. Notice the islands on the graph that look like ripples on water. Those are efficiency islands. It is desirable to have our point plotted right in the middle of the graph, although anything down to about 60% efficiency will work. Notice that our point is way off the map for this turbo. The turbo will still make boost, but will not be efficient. This is a bad selection for our project.

Our point is off the map to the right. What if our point fell in the surge limit area to the left? That would be very bad. In fact, it would surely cause damage to the compressor. In this area, the air flow is unpredictable and changes direction.

Let’s look at another turbo compressor map.



This is a map from a T76 compressor. Notice that the point lands right in the 70% efficiency island. This would be a perfect turbo for this setup.

Kevin has pretty much this identical information under his website, only it's a little easier to understand and there are actually maps too. www.posracing.net . It's in the tech pages, under turbo compressor maps.

TDO5H small 16G flows 35.7 lbs/min stock, so I'm not sure how much more it will flow ported, I'm guessing maybe another 1-2 lbs/min. So you're probably looking at about 36.7-37.7, maybe. Scottsee was pretty much correct though, I just like to be more precise. :p



Actually Shape pulled 44lbs. :)
thanks for the info man

:thumbsup:

The EVO8 turbo runs about 40-42 pounds in daily driver trim for me, and I have seen up to 43 at the most. The small and big both flowed 35-38 for me. depends on air temp and there is also some variation in measurement between MASs.

Good to see you back Kevin