FPR questions

[ZyklonBZombie]

i have a quick question. i have read that the nonturbo 4g63 FPR flows more gas than the stock turbo one? can anyone verify/discredit this. i am getting alot of stuff for my car (including fuel pump) and am wondering if this will help against fuel cut or anything (not that i'm gonna up the boost yet ... but just to have the knowledge when i need it)

 

[kpt4321]

It has a higher base fuel pressure, which will make the injectors flow more for the same pulsewidth.

Just raising the fuel pressure will not combat fuel cut, you need to reduce the airflow seen by the ECU.

 

[ZyklonBZombie]

thanks for the info ... i don't think fuel cut will anywhere new a problem for me ... i am putting a td04 (my car is 5spd ... i do have a 14b but it is in another car and since i plan on getting a 16g soon i will make do with that one 13g if i'm not mistaken) and will only set the boost to like 10 psi (with walboro fp i now have).

 

[candela]

I have no idea what you just said....

ANyhow the NT regulator is not a good idea anytime, even if you want more fuel pressure. Non linear w/boost, and a higher load on them the entire time you are in anything driving cicumstance but boost, this will give driveability issues.

 

[Bohrn]

been there, done that.

While I hate to disagree with a wizeman, the N/T regulators are rising rate, and do compensate for boost. I am a technician at a GM dealership, so I hooked up our fancy fuel pressure guage to my rail at the filter and taped it to the windshield to see if it was. Took my car out on the hiway, and did some 3rd and 4th gear pulls. It is indeed a rising rate, at 1:1 as far as I can tell.

Now that said, with a 255lph pump, it can't bypass enough fuel and it gets overrun. And not evenly, or repeatably. You get fluctuations in your fuel pressure. Not consistant at all. This leads to drivablility issues, crappy mileage, and makes it VERY hard to tune. I've been living thru this for several months now. There were days where the car was great, and others were it was just ugly. Even both in the same day.

So my advice is, unless you have a smaller pump, don't do it.

I'd also add that people with a modified stock 1g regulator with the B&M Command Flo don't go for a big pump either as its still your stock regulator under there.

 

[candela]

While I hate to disagree with a wizeman, the N/T regulators are rising rate, and do compensate for boost

Well I really do not have experience with NT regulators but I never said they were not rising rate (even though I doubt they are)... I don't know how much validity your taping the gauge to teh windshield and doing 3rd gear pulls on the highway and watchign to see the FPR rise in a 1:1 reference with boost (i think that would be kinda hard ). I jsut said that driveability issues will occur as you said. since base NT fp is ~47-53 psi.

So even if the regulator WERE rising rate, who knows what the reference is and that base is to high IMO. All kinds of issues would happen outside of WOT (even in WOT tuned IMO). If it were my system i wouldn't want to be running to high of pressures anyhow, as fuel components just don't last as long at really high pressure: runnign a base of ~50psi and running boost on top of that (assuming its RR) is to much IMO.

Anyhow KPT is right as well, it will NOT help in fuel cut

 

[Bohrn]

no definately wont help fuel cut.

as for the guage, its not a guage like we usually run, its a professional fuel injection service package with all sorts of adapters, couplers and lines. And it comes with a 3" guage with a rubber surround that is supposed to be taped to the window so that you can tell if a customers car has adequate fuel pressure under load.

The n/t reg that I had at least was 1:1, I could accurately and repeatably watch the boost guage and the fuel pressure guage climb and drop. It was linear and it worked.

But that said, I agree with you about the base pressure being way too high, and its hard to tune because it gets overrun by the big pump.

I wouldn't suggest using one unless you have a smaller pump and you are just trying to get more fuel out of your stock injectors. a 190 pump and one of these may be a cheap way to hold off buying 550's.