throttle body size

Hi guys maybe some one will help me my car is running 210 whp now im looking to go efi and i m get erring all it is need it my problem is i don't now what throttle body size should i use i don t want to go to small or to big

As a starting point, 100hp per square inch. But also look at what boost pipes you'd use, and what fits.

you have about 240 crank, so ~45-50mm is a good starting point, certainly not less than 45mm, but don't worry about the size too much, more the fitment.

would an mgzr throttle bodie be any good they come in either 48 or 52mm (52mm are only fount on the vvc engined cars)

Tanks for the help

Mk 4 Ford fiesta zetec, it's a 45mm throttle body, should do the job nicely