I know that upgrading injectors on the big Ford/Dodge/GM diesels can make a fairly big difference in HP and torque numbers, but does upgrading the injectors/fuel rail on a Civic make any difference unless you're running with spray?

 

Unless you need more fuel, because of boost, internal work, or a retune that gets injector duty over 90%, no, all you'll do is waste money.

 

Your car isn't taking in any more air, thus doesn't need more fuel.

You'll just run rich.

 

I had a feeling that was probably the case. Thanks guys!