AFPR questions

[turbodohc20]

Hi,

My fuel pressure regulator was being overrun by my 255 pump and my fuel pressure was way high. I installed and AFPR and had a few questions about it. I read that the stock FPR will increase fuel when boosting. Will the AFPR do the same? there is a nipple for Vac line on it.
Another question is do I need to up the fuel pressure since I have 3" intake pipe w/k&n and 2.5" UIP? If I up the fuel pressure will that give me more fuel or the only way to get more fuel is bigger injectors and SAFC?

Thanks,

 

[kevingst]

You won't get more fuel with the regulator, not like you need. It'll just make sure the fuel you need is there. The afpr will raise with boost. Which one do you have? Make sure it's one with a 1:1 rising ratio. And no, you don't need to up the fuel pressure with those mods. For more fuel, you will need the injectors and something to tune with.

 

[scottsee]

set your afpr to stock, if it has the 1:1 boost ratio it will ajust itself. what afpr did you get?

 

[turbodohc20]

You won't get more fuel with the regulator, not like you need. It'll just make sure the fuel you need is there. The afpr will raise with boost. Which one do you have? Make sure it's one with a 1:1 rising ratio. And no, you don't need to up the fuel pressure with those mods. For more fuel, you will need the injectors and something to tune with.

That's what I figured. Thanks!

The AFPR I have is from FUll Throttle speed and style located in Michigan. It doesn't have a brand or anything, the receipt just says 1G bolt on AFPR. I think they would know what it would have to be 1:1, I hope Here is a pic of it.

 

[turbodohc20]

set your afpr to stock, if it has the 1:1 boost ratio it will ajust itself. what afpr did you get?

I set the pressure @ stock but my fuel press gauge is on the Fuel filter. I'm sure that's probably not going to be a the right reading is it?

 

[kevingst]

That's what I figured. Thanks!

The AFPR I have is from FUll Throttle speed and style located in Michigan. It doesn't have a brand or anything, the receipt just says 1G bolt on AFPR. I think they would know what it would have to be 1:1, I hope Here is a pic of it.

You're good to go with the full throttle afpr, it's 1:1. And reading off the filter is ok.

 

[turbodohc20]

Great, Makes me feel much better. I just read about the FPR raising when boosted a few days ago and wasn't sure if the aftermarket one did or not.

Thanks

 

[Talesin]

Anyone know how many psi are usually lost across the fuel rail? I've got my AFPR set to 27psi (vac on), but it still smells like it's running rich, and is only giving about 20mpg... as opposed to the old one, which was 36psi (screwed the injectors) and was giving the same mileage. Fuel system won't hold pressure when the car's off, though I think that's a little bit of teflon tape in the AFPR aperture allowing it to leak back through the return. Gotta pull that thing off completely again and get that piece of crap OUT of there. Still suspect a damaged O-ring on the fuel pump fitting, but I *really* don't want to try to take that thing off, given how much of a b***h it is rumored to be to remove.

 

[foreverinvayne]

from what i've heard, upping your fuel pressure will force the car to run more rich because the car thinks it has a certain amount of fuel pressure, and the more pressure will cause more fuel to shoot through the injectors when they open.

 

[sweet97]

You won't get more fuel with the regulator, not like you need. It'll just make sure the fuel you need is there. The afpr will raise with boost. Which one do you have? Make sure it's one with a 1:1 rising ratio. And no, you don't need to up the fuel pressure with those mods. For more fuel, you will need the injectors and something to tune with.

Upping the base pressure will give more fuel across the board or rpm range perhaps is a better word.Most injectors are rated at 43psi.If you are running higher boost than stock a higher base will give you more fuel at the higher boost pressure. I run 45psi,vac.line removed which is the pressure the system will get under boost plus 1:1. So at 20PSI I get 65psi pressure. An AFPR is another tuning tool. I can tune it out at idle and midrange but have it at the higher boost level to prevent knock or it will allow me to lean the WOT setting for an increase in timing, again without knock. Many uses for an AFPR. I use the same compressed air regulator fromfullthrottle. Mark