Just installed 4 750cc injectors and my buddy told me I need a fuel pressure regulator.

For 12psi on stock turbo, tuning via an SAFC and an Innovate LM-1, with a Walbro 255, do I need an fpr?

I searched and just found people talking about aftermarket installations, not when you actually need one...

Car has not been started yet.

 

not with a walbro

 

What size injectors can a walbro stop putting out sufficient fuel for? Is that when you need to go aftermarket fpr?

 

By the way, I have done some reading and to clarify.

My car now has 4 x 750cc injectors and it started right up on the STOCK ECU.

It hunted for an idle but when I dropped the fuel about 20% (via an SAFC) it holds a ROCK SOLID 800 rpm idle!

The only problem is, I hear a loud hissing now...
I think I have a vacuum leak... Wouldn't my idle bounce if I had a leak? I'm boosting half a psi lower than usual...

 

the only reason you would need a different FPR is if your fuel pump outflowed it. In that case your fuel pressure would be too high. It has nothing to do with size of you injectors. Im running 750cc and 1600cc injectors on the stock FPR, lines, and rails with a walbro 255 no problems

 

Yea, you'll be fine with the stock FPR and a Walbro. The stock FPR, rails, and configuration have been proven to handle a lot more power then you'd think. The aftermarket adjustable FPR and the SS lines always look cool though!

 

When I nail it, it spools real slow and feels slower than it used to from 6-7k. Too much fuel? My AFRs are only like 11.0... at 10psi...