Calculating intercooler size

[rolleraction]

Hi all,

Can someone point me in the right direction in terms of working out an appropriate size for an air to air intercooler for a turbo 4AGE.

Front mount and to able to function with a race engine in race conditions (ie full boost - wot -high revs most of the time plenty of air passing through due to high road speed - high boost (well the most available using a 36mm restrictor & pump fuel - for IPRA)

The samller the physical size & lighter weight the better - without compromising too much on efficiency.

Any pointers from those in the know???

[YelloRolla]

Any pointers from those in the know???

Jeez that cuts things down a bit. I am NOT in the know, so I will direct you to http://www.are.com.au/
These guys do a lot of testing both flow and temp reduction - they are in the know (I think?)

[MS-75]

Actually calculating a size is a very complex exercise. The number of variables is huge, as are the number of values you need to fix prior to starting.

The statements you see in most ads regarding 'efficiency' (Only Xpsi drop at Ypsi boost!!) are totally pointless, and the vast majority of those involved in selling core have't any real idea on the proper calculations or even the meaning of what they are stating.

Having said that-I've never bothered to actually number crunch such a choice as the amount of empirical date floating around is perfectly sufficient to allow reasonalble selection.

One of the major problems calculating size is that end-tanks have a massive effect on performance of the core. You can have an awesome core, and wreck it by putting crap tanks on it.

As a couple of rules of thumb-

Select something that fits into the front of the car, with nice smooth tanks on it (ie-don't squeeze a huge core with crappy tanks in).

Choose something with internal finning for increased surface area and hence increased heat ransfer rate.

Go for the HEAVIER cores as they have greater heat absorbtion ability. (cores work as heat sinks mostly under acceleration and then reject the heat over a period of time.)

Certainly ARE are one of the very few shops around who actually understand what's going on, but ultimately they'll give you a core based on experience rather than calcualtion.

If you do want to have a go though, go to a UNI library and ask for HEAT TRANSFER by JP Holman

Sean=-)

[rolleraction]

Cool, Many thanks for the info.