Now that I'm going turbo, should I get rid of the vacuum reference for my fuel pressure regulator and just run it at a straight pressure all the time?

 

No, you want to leave it connect. This will raising fuel pressure 1:1 when under boost. It will also reduce fuel pressure at idle.

 

Exactly, I just figured that under boost it would be hard on the pump to push that much pressure.

 

It is a little harder on the pump, but that's the way it works. If you're going turbo you probably have an aftermarket pump anyway (or you should), which would last longer than a worn out stocker. I like the Walbro 255HP pumps (HP for high-pressure) for boosted applications if you're making moderate-or-less power levels.

You actually have to keep the vacuum (or boost) reference with forced induction, otherwise the injectors will flow less because the pressure at the cylinder head end of the injector will lower the pressure differential across the injector if the fuel rail pressure stays the same. The 1:1 rate of FP rise will keep the flow the same.

 

Excellent, thanks for clearing it up for me!

 

You're welcome, no problem.

 

so a stock type regualtor will give the corect fuel for a turbo setup ....with just a fuel pump ? Just trying to learn about the fuel setup I need for mine

 

Yes, if you have injectors big enough to flow the amount of fuel your engine will need (which requires the ability to tune for those).
This is the proper way to do it.

Otherwise you have to get a rising-rate FPR (FMU) to add to the stock setup to force enough fuel through smaller injectors. These devices raise the rate of fuel pressure to boost at a higher-than 1:1 ratio, it's more like 4:1 or 6:1, so that if you were running 10 psi of boost the fuel pressure would increase by 40 psi at a 4:1 ratio. This is very hard on the fuel pump, though, and is unideal also because it is harder to get an accurate fuel tune. They do work well enough for a lot of people, though.

 

You don’t have to, but it is easier. You can actually program/tune the ecm to deliver less fuel under high vacuum conditions and more under boost (we did that in my brother’s car till he ran out of injector without compensating for boost pressure).

The stock regulator just bypasses the fuel that isn’t necessary at the time, the stock one will work for most setups, probably well into the 700hp range.

You need a pump big enough to flow whatever amount of fuel you need at whatever pressure you see at the maximum boost pressure, and then some way of adding fuel (either appropriately sized injectors and reprogramming for them or an FMU)

 

Well yes, I was assuming the typical proper injector sizing methods as a constant, meaning it wouldn't have enough fuel if it was done that way. Of course tuning around that is also unideal, and it's better to just leave the vacuum source connected if it already exists, such as in this application. Sorry for the confusion to any who have been confused.

 

Not confusing. I think you two are saying the same thing in the end.......Leave the vacuum ref. on the press. reg.

It is all a matter of opinion and what you have for a pressure reg. If I have too small injectors for the app., then I turn up the pressure (within reason) and rely on the vacuum port to lower the pressure at idle. If the inj. are adequate, I run stock press. and use the vacuum port.
Both setups require ECM tuning.