I am in the middle of restoring a Rx-4, the car has a new from mazda 13b in it with around 4000 kms... so pretty much brand new.

I do not want to run a carb I would like to run a FI setup like the ones offered by Tweak It and Injection Perfection.

I would like to run it N/A while I get together a turbo setup. The turbo I will be going for in the future would prob be a S5 turbo maybe sent to BNR for a stage 2 or 3 upgrade... but thats later on down the road.

What I am wondering is what size throttle body and injectors would I need to be able to run N/A for awhile but be able to boost it later on without having to buy a new TB?

The motor is stock port '74 spec 13b, after a turbo I would like to see hp numbers in the high 200's or low 300's. But for running N/A it doesnt really matter as long as it runs nice.

Thanks in advance

 

since a 48IDA carb works, 48mm efi throttle bodies should be way in the ballpark. since its EFI you can go bigger, 50mm or even 55mm.