Intercoolers

[quattroTurbo]

The pressure drop increases with larger intercoolers because more work is required to fill the extra capillaries with pressurised air. Someone asked the difference between plate and bar and fin and tube. Plate and bar has more meat to its air channels and has many more internal fins. It weighs more because it is designed to be that way - a heat sink - which is what an intercooler is. Fin and tube is more like a radiator, with less intricate internals and far less metal to act as an efficient heat sink.

You can improve the efficiency of your larger intercooler by designing better (air-flow optimised) end tanks. This can be achieved with internal deflectors and vains. The examples on this thread look a bit sad in that respect.

[4WheelDrifter]

The trouble with making the core flow better, is that the air moves faster and has less chance to be cooled.

[Audi_CQ]

The pressure drop increases with larger intercoolers because more work is required to fill the extra capillaries with pressurised air.

You can improve the efficiency of your larger intercooler by designing better (air-flow optimised) end tanks. This can be achieved with internal deflectors and vains. The examples on this thread look a bit sad in that respect.

A bit ekstra lag yes, but bigger pressure drop???
The same amount of air is going through independent of IC size, so the pressure drop is smaller in a large IC because of less resistance.

Another issue is that with larger IC's(many rows, not just extra lenght) the airspeed is lower and design of end tanks isn't so critical. My end tanks isn't excactly optimal, but it sure works

Cheers,
Roger

[quattroTurbo]

Horsepower is dependent on flow. Restrictions reduce bhp, simple as that. A larger intercooler will reduce air speed, which when measured, will show reduced boost - always. No use saying it doesn't without actually testing your theories with proper measuring equipment. Installing a larger intercooler is a balancing act. Idealy, a 500mm x 280mm x 75mm core in plate and bar with well designed end tanks is all anyone would need for 500bhp+. If you are unhappy with that, then install Aquamist - but make sure you have a programmable ECU or you will loose power. The effect is like having a super large intercooler, but without the lag and pressure drop.

[sorens2]

Theory

[Audi_CQ]

Horsepower is dependent on flow. Restrictions reduce bhp, simple as that.

A larger intercooler will reduce air speed, which when measured, will show reduced boost - always.

No use saying it doesn't without actually testing your theories with proper measuring equipment.

1. Totally agree

2. Large IC reduce airspeed through the IC yes and lower speed=less drag, but speed at inlet/outlet the same as small IC if openings are the same size on both IC's and the amount of air is similar(the amount the engine can "swallow" independent of IC)

3. I havn't tested, just tried to remember what I learned at school about flow dynamics mixed with some common sense. I might be wrong so if you have tested please post results

Happy New Year

Roger

[Sweeper]

Roger brakes all our previous thoughts and dreams.

Nice one. I'm for Hybrid intercooler , should be optium considering out space after bumper.

[quattroTurbo]

There is a pressure drop because the intercooler acts like a valve. The air travelling into the intercooler looses some of its volume as it passes the intercooler, before it can be used by the engine. There is a very simple test. Take a boost reading before you install your larger intercooler, then after. There is always a pressure drop.

[sorens2]

That´s true. Never heard of that teori before. But I can see that the cool air will loose volume. Thanks for the info.
Still I think that a large IC is for the better due to temperature drop.

Søren S2

[S2central.net]

Just remember n = PV/RT

Intercoolers are a compromise... The advantage of better cooled air temperature *may* be reduced if excessive pressure drop forces the turbo into less efficient operating range by nature of the higher pressure ratio needed to provide the target boost level in the manifold.



Paul

[SteveH]

Just got my intercooler from the States. It only took 3 days to get to the UK

I have the same unit as the one Sal has. Ordered the 3 inch unit and they sent a 4!!

[Beetie]

Nice one Steve! Just make sure they dont charge you for a 4" one!

[audiman]

Good luck fitting those 4" beasts. The 3" ones were bad enough. Gonna take some serious hacking up of the front bumper

[Doug_RS2]

I think you will struggle to get a 4" deep behind an RS2 bumper - you might have to angle it so the bottom sits further back.

Thinking out load - the 3B will sit 10mm further back than an ABY - get it mounted high, touching the top of the bumper and it might fit.

[audiman]

Yeah agree, the crank pulley is shallower on the 3B