This is straight from the Garrett website:
The Garrett Performance Intercoolers (also know as Charge Air Coolers) work together with the turbocharger as a part of the total induction system. When air is compressed in the turbocharger it gains a great deal of heat. The heated air has lower oxygen density and therefore is not able to produce as much energy when fed into the cylinders. The job of the intercooler is to remove heat added by compression in the turbocharger and in turn promote more thorough combustion yielding more power, less emissions, and greatly reducing detonation.
Garrett intercoolers are Bar and Plate and made in Mexico, a large majority of other intercoolers including brand names are made in china, to give you an answer on what would be more effective depends on what your after, for the most effecient cooling you would go for a 3in (75mm) thick for most effecient power 4 1/2in (115mm). The Garrett cores we have in stock have about 20 fins per inch where as others have approx 8 fins per inch.
We can fit most intercoolers for approx $1650 the size 24in (610mm)Length
x 12in (300mm)Height x 4 1/2 (115mm) Wide but I recommend you give us a call or come and see us for a proper quote.
I hope this helps
Sarah
www.buzzengines.com