boxstahboy

Hi everyone. My friend runs a civic around town and bought himself a bigger bore throttle body. I was wondering if we can get those for our cars and if we can, what are the pros and cons. And as a side note, I was hoping someone could explain what exactly a fuel pressure regulator does and if it's worth putting in.

RoadSpike

You can get the STI TB and put it in if you like.

The fuel pressure regulator keeps the fuel pressure generally on most vehicles around 8-12psi. With aftermarket parts you can boost the fuel pressure to much higher levels.

This does a couple things. It produces a finer mist in the fuel dilivery for injectors, and also allows more fuel to be dumped in by the injectors.

boxstahboy

I see. But with the fuel regulator, would the injectors be working harder, the same, or less? And combine that with the fact I'm still running stock injectors and a stock fuel pump. Should both of these things be upgraded together?

Myxalplyx

Yes, your injectors will be working harder. Whether your fuel injectors and stock fuel pump should be upgraded together depends on how much hp you are trying to attain. If the hp goal is out of the flow capacity of either your stock fuel injectors or stock fuel pump, then either/or needs to be upgraded.

I can not tell you the flow rate of either your stock fuel injectors or your stock fuel pump. However, the most fuel pressure I have ran on my 2.2ltr Outback Sport was 70psi. This was done over and over again and was the 'fault' of running a 60 shot of nitrous pushing the fuel pressure up. This was on top of 5psi of turbo boost. I never had any problems with not having enough fuel.

For N/A purposes, I don't think you'll have any concerns of needing to upgrade your fuel pump or your fuel injectors.

boxstahboy

thanks for the info man. So from what I gather a fuel pressure regulator would be a decent upgrade for now. Then later on maybe do the pump and injectors.

Pat L.I.

boxstahboy,
i think you mis-interpreted. You will not need to upgrade your fuel pump, pressure regulator, or injectors until you get to the very limits of modification.
If you are running common bolt-ons you will have no need to upgrade these parts.
With nitrous, boost, or an all out N/A monster then you need to start researching them.

boxstahboy

oh ok. now I get it. thank you for clarifying. the fuel system the way it is, is just fine.