Im not really on the same page as you at the moment, if you could shed some more light on what your trying to say that would help. I think you are trying to explain that the stock fpr is actualy not letting the aftermarket fpr not do its job and build pressure. If that were true (correct me if im wrong) there would be no way for me to hold 50 psi constant at idle, and for it to also rise as boost comes on. I always believed that the stock fpr didn't build anywhere near enough pressure for that theory to take affect. Dunno if were on the same page.......

 

I thought you were supposed toi keep the stock FPR for idle and emissions purposes. But, what about the SDS guys that are pushing 16-17 psi? don't they still have the stock FPR in place? How do they get all the fuel?
I have seen that part you are talking about, a friend of mine has the stock FPR removed and has this in place http://www.camskill.co.uk/products.php?plid=m3b49s9p606 to the left from the FPR. Is that the part you are talking about? His car drives pretty good he has nitrous, the thing is though, he's had the SES light on since he did that.

 

I thought you were supposed toi keep the stock FPR for idle and emissions purposes. But, what about the SDS guys that are pushing 16-17 psi? don't they still have the stock FPR in place? How do they get all the fuel?
I have seen that part you are talking about, a friend of mine has the stock FPR removed and has this in place http://www.camskill.co.uk/products.php?plid=m3b49s9p606 to the left from the FPR. Is that the part you are talking about? His car drives pretty good he has nitrous, the thing is though, he's had the SES light on since he did that.

Pacoslant, that is what I'm referring to, the exact scenario about your buddy.

In the pic of that adjustable FPR you put up, it appears to have the fitting to remove your stock FPR.

 

Im not really on the same page as you at the moment, if you could shed some more light on what your trying to say that would help. I think you are trying to explain that the stock fpr is actualy not letting the aftermarket fpr not do its job and build pressure. If that were true (correct me if im wrong) there would be no way for me to hold 50 psi constant at idle, and for it to also rise as boost comes on. I always believed that the stock fpr didn't build anywhere near enough pressure for that theory to take affect. Dunno if were on the same page.......

This thread is a discussion on the pros & cons of using the stock FPR.

 

Well i have already disable my stock FPR. Idle is fine. emissions- i have not cat so i can;t speak of emissions. If you have a turbo kit most likely you are not passing emissions anyway so... I'll keep everyone posted

 

My Zex kit used the vacum hose from this to try and regulate the fuel pressure.

 

I would figure that the stock FPR would hinder the pressure that any aftermarket FPR would build. The small amount of fuel line between the stock FPR and the aftermarket FPR would be highly pressurized however. But still, no solution.

In theory, it seems that using a stock FPR with an aftermarket one would be useless.

 

Hey bish that's what i said on the other board :lol:

 

I would figure that the stock FPR would hinder the pressure that any aftermarket FPR would build. The small amount of fuel line between the stock FPR and the aftermarket FPR would be highly pressurized however. But still, no solution.

In theory, it seems that using a stock FPR with an aftermarket one would be useless.

I don't think is useless, just think about this. How can the people with an SDS running 17-18 psi can have enough fuel to support it? Don't think I am trying to say that having an SDS is better cause that's not what I am saying. I am also having problems with the FPR supplied with the SDS. Maybe is just a matter of getting the right FPR. Check out http://www.bellengineering.net/Pages/products_FPR.html they make FPR's to use along with the stock one and one without it also.

 

Injectors size and fuel pump along with the grey box can make up for lack of fuel pressure.

 

I don't think is useless, just think about this. How can the people with an SDS running 17-18 psi can have enough fuel to support it? Don't think I am trying to say that having an SDS is better cause that's not what I am saying. I am also having problems with the FPR supplied with the SDS. Maybe is just a matter of getting the right FPR. Check out http://www.bellengineering.net/Pages/products_FPR.html they make FPR's to use along with the stock one and one without it also.

This is what we have right now. When I used that RRFPR with the stock injectors I could not get anything better than 13.5:1 when we were tuning the car. I removed that RRFPR in favor of bigger injectors and managed to get quite a rich tune.

BUT! What I stated in my first post is that SOMEHOW API is managing to get a proper tune all the way up to 9psi on stock injectors. The only way I can see that happening is taking out the stock FPR and using an aftermarket Fuel Pressure Regulator or Fuel Management Unit exclusively... NOT augment it with a Rising Rate Fuel Pressure Regulator.

 

Just throwing something out there;
Here is what AAI uses on their RS/GS Turbo kit and it works perfectly from what I hear, and what I will soon find out.

I will be installing this and gettin g my car running this weekend with it. Hopefully it isnt too hard to tune.

Here are my parts, as AAI recommends.

And the blue piece in this pic is what Donald gets custom made for the end of our fuel rail. An adapter that gets a 90degre elbow then feeds the SFMU.

Why dont you guys try something like this?

 

Injectors size and fuel pump along with the grey box can make up for lack of fuel pressure.

I can hold 55 psi at idle on my stock pump on a adjustable fpr with the stock fpr still there. How much more pressure would you want?

edit: Only reason stock pump is in is because my warlbro ate itself and I need my car for work, just need to get a day off so i can wake up early enough and call ripp and have it warrantied.

 

BUT! What I stated in my first post is that SOMEHOW API is managing to get a proper tune all the way up to 9psi on stock injectors. The only way I can see that happening is taking out the stock FPR and using an aftermarket Fuel Pressure Regulator or Fuel Management Unit exclusively... NOT augment it with a Rising Rate Fuel Pressure Regulator.

OOOOHH OK I see what you meant in the original post. I think you're right, that might be the only way to do what API is doing. But I also don't think it's USELESS to have an after market FPR I mean is has worked for a lot of people.

 

I dont see how you can say that removing the stock fpr is the "only" way to make it work when you have never tried the fmu route yourself.

 

I dont see how you can say that removing the stock fpr is the "only" way to make it work when you have never tried the fmu route yourself.

We have tried the RRFPR and the FMU (in Neffarious' case). All of our cars are running 5.8psi and we could not get stock injectors or (275 injectors in Neffarious case) to tune safely even at 5.8psi.

We have tried it. I just wish I knew now what I knew then to take that stock FPR out in favor of a Fuel Management Unit instead of this damn RRFPR.

 

If you used an adjustable fmu theyre not as good as a nonadjustable. Should have used a vortech 12:1. Dunno if thats what API uses, But i used it on my turbo setup.

 

eww, do my eyes deceive me or does that guage have a nipple to feed fluid to it? fuel pressure guages should use an electronic sender so you can keep all those bad fluids on the other side of the firewall, its called a firewall for a reason.

 

the gauge stays under the hood.

 

the gauge stays under the hood.

:agreed:

 

removing the stock FPR took me from 13:1 to 11:1. I ran it on a wideband yesterday.

 

Not everyone knows what that means Joe.

To further his explanation for those who dont know, removing the stock FPR made him run waay richer, so it was in fact hindering the efficency of his FMU.

 

i bet he's gettin better mileage now too

 

We shall see

 

i am running rich so my milage is ass. Lean = good mileage. I am gonna get a re tuen this wek or so I'll keep everyone posted