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.