what is the difference between the engines, etc, what is the better more tuneable engine?

 

The basic engines are practically alike. If not identical, then equal at least.

The FRST has the EFI parts, wasted spark ignition, and such to easily take accept any aftermarket management. The turbo is really really small on teh other hand and suited for the 132hp it has as standard.

The ERST on the other hand has a bigger and better exhaust manifold and turbo. The standard turbo can be pushed to over 200+hp although not the wisest move.

 

it just i have a xr2 and am looking to fit a turbo engine but dont know which one would be better to use

 

Go for the FRST one, the EFI management is easier to install into the XR2 and a tad more reliable and tunable.

 

is it just a straight swap putting the t3 on to the frst engine? i am thinking of going for the frst engine with t3

 

yes it will swap over but i think u have to moddify the down pipe !?