right then, Yes it is true that the colder the air going into the turbo is the denser it is thus meaning a greater amount of oxygen is injected creating a better burn and thus a quicker car. And yes you would think that by having two intercoolers you would get more cold air.
But!
What you have to bear in mind is how quick you can get the air into the turbo, now if you have two intercoolers rigged up yes you have twice the cooling area but you will end up slowing the air speed down even more and actually end up retarding the performance. The only reason i know this is because i tried it with a mate on a punto GT turbo, they have the small one like on the golfs and you can then uprate this to a full on front mounted jobby like yours, what we did was then rig up both intercoolers and the car ran like sh!t, it was spluttering all over the place.
You will be better off just rigging up the new front mounted jobbie for a good performance gain, if you want to go further then use the space where the old intercooler sat to plumb in a cooling radiator for a water injection set-up, that would be a lot more use.
