Can you use a old radiator for a Intercooler???

[Wyreth]

What is the actual cfm of a turbo? Does any one have that data?

You can easily calculate that from the compressor map of whichever turbo you're running. (air density at sea level = 0.076lb/ft3. Thank you google.)

Does any one no if there is an optimum temperature? To do effective cooling of the air.

I don't know about an "optimum" per say. However, the higher the temperature differential between the compressed air, and the ambient air. The more effectively the intercooler will work.

Looking at the core picture Leeland posted and you can see the kind of surface area the internal passages of an intercooler have, vs the internals on a liquid radiator.

 

[justinray]

Optimum air temp is an odd question. As cold as it can be without putting out any hopes of combustion would be optimum, but the best feasible temp would be whatever ambient temperature is at the time.
On a more relevant note, unless you have exceptional fab skills, by the time you plugged the cap, and changed the inlet/outlet size/location, you could buy an intercooler.

 

[FORDF250HDXLT]

theres no point in doing this.you can source intercoolers for around a hundred bucks.it's the piping,custom intake hat,silicone couplers that get ya,not the cost of the fmic.
http://www.ebay.com/itm/31-x11-75-x...Parts_Accessories&hash=item1e76f0c056&vxp=mtr

 

[Wicked97]

It does not work.
A radiator does not have anywhere near enough flow for air on the inside and it doesn't have enough surface area to cool the charge.
Some ricer tools tried it on a Dyno day several years ago.
Great in theory not so great in practice.

 

[jaluhn83]

Rated coolant flow on an IDI is 70 gpm.... that's 10 cfm of water. Max air flow on the turbo outlet side is going to be somewhere around 350 cfm. (inlet air flow is closer to double that, but on the high pressure side flow is going to be close to the same as an NA truck, just at higher pressure and density)

Air does flow easier than water, but the tanks and core is designed significantly differently for an intercooler. I think you'd wind up just making a giant restriction in your intake system.

You could certainly use an old radiator as part of an air/water system, but it's somewhat overkill.

 

[rlb245]

Thanks jaluhn83 that's the numbers I was looking for.

 

[jaluhn83]

CFM is pretty easy to figure out, at least ball park.... Displacement per revolution (420/444 CI) times rpm/2 (4 stroke, so every cylinder fills once every other rev) and then convert to cfm (divide by 1728)

In reality there's also a factor for volumetric efficiency - accounting for the fact that each cylinder woln't completely fill. Typically 85% is a good number, so air flow would actually be roughly 85% of the above number.

At 3300 rpm this comes to 360/340 cfm for 6.9/7.3 respectively.

Now we factor in the turbo....

You know that flow into the cylinders is still roughly the same, since the cylinders are still filling the same amount at the same speed, so flow into the intake is roughly the same, just at a higher pressure, so more weight of air is squeezed into the same space, but the volume is the same.

Gas behavior can be modeled using the ideal gas law: p*v=n*r*t (remember physics class??) 'r' is a constant and 'n' is essentially the number of molecules of air which remains constant in this case. Assuming temperature remains constant (which it doesn't, but close enough) you get p*v=constant, so if you double the pressure (measured as absolute pressure, so 15 psi of boost is doubling the pressure) you half the volume. Or looking at it the other way around, making the same volumetric flow at double the pressure (15 psi boost) requires double the air flow at atmospheric pressure...

The short version of the above is that if you double the flow of an NA engine it's a decent ballpark for a turboed engine.

So figure around 700 cfm on the inlet side and you should be safe.

Mind you, this is very much a ballpark figure, but for the purposes of general planning it should be reasonable.

 

[rlb245]

The object of the enter cooler it to lower the temperature of the of the air in the intake correct? The enter cooler from what I see is piped in before the turbo. Doesn't the turbo reheat the air we just cooled off? Or am I wrong on the enter cooler hook up

 

[jaluhn83]

Intercooler.

Yes, that is correct. Cooler air is more dense, so you get more air in the cylinder. It also helps egts and heat load on the engine.

It's on the high pressure side of the turbo.

Air flow is air filter-turbo compressor-intercooler-intake. Sometimes it's confusing to see exactly how the piping is run, but you'll never have a cooler on the air filter side unless it's something really wacky.

Some engines use a air to water intercooler built into the intake (also called an aftercooler) which can be confusing too. I know some 8.3 Cummins are setup this way.

 

[rlb245]

That makes sense to me now. Found this while searching. good stuff

http://www.gnttype.org/techarea/turbo/intercooler.html

 

[Oog]

Well today I tried that with a brand new radiator out of va 99 toreass. Only two ports with no radiator cap. Used a shop vac and a high quality completely accurate test of a ping pong ball. I think new radimaters do flow well.

 

[Wicked97]

Some do but its worthless as an air to air.