I was planning using a rising rate fuel pressure regulator for my 3400 SC (work in progress).

Whats your thought about this?

I've read that its a good thing for low boost application (below 9PSI) ...my setup will be low boost.

I would not recommend using a rising rate regulator with a boosted application. Your fueling will be way off from optimum. The best way to mamange a boosted engine is with a PCM reprogram. You can buy PCM scanning/editing programs for your PC that will allow fueling and / or timing changes to accomodate boost. That is really the best way to do it.

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87GT 3.4 Turbo- 0-60 5.2 seconds
2006 3800SC Series III swap in progress
Engine Controls, PCM goodies,
re-programming & odd electronics stuff
" I'M ON THE LOOSE WITHOUT THE JUICE "

I have never used one so I don't speak from experience. I do know that many supercharger kits from Procharger and others use the boost referenced rising rate regulator to make their kits 50 state legal.

I took the info from a book on supercharger in the fuel injection section. They wrote thats its a good idea to use on low boost application . Also they point to the fact of using right sized injector, reprogramming the ECM, increasing the pulse width (if necessary) and increasing fuel pressure , by a manually set fuel pressure regulator or a rising rate fuel pressure regulator, installed inline with the stock regulator (and a higher pressure fuel pump).

Heres an extract of the book:

Increasing system fuel pressure as a fuction of boost pressure is a reasonable method of increasing fuel flow to accomodate boost pressure to about 9 psi. Fuel flow changes trhough a nozzle are proportionnal to the square root of the pressure change across the nozzle. A boost-pressure-powered (rising rate) fuel pressure regulator can be made to drive fuel pressure up rapidly, to keep pace with rising boost pressure......
....Proportionning fuel pressure to boost pressure maintains the timed nature of EFI, keeping fuel delivery proper relative to the air-mass rate of the flow.

That make sense to me...and I'm wondering if this "add-on" will help in the tuning of the EFI and help keeping dangerous "lean condition" away.

Also are these thing are reliable in itself?

Hudini, if in their kit the use of this device help keep the car 50 states legal, its a good idea on my side of the border to use it...If is there a thing I dont want me to happen is being obligated , in a near future du to "new smog regulation", to keep my car off the street. If my setup can be more efficient "pollution wise" than a stock 2.8, I think I 'm safe to think to be able to keep the car on the street...

[This message has been edited by perry rhodan (edited 10-07-2007).]

its a band aid method that has better alternatives. a big fuel pump and an adjustable fpr is just as good. i ran one before on an engine i added an SC to later and it went from 3-4bar but i just slapped a static 4 bar in and it ran a lil better.

What are you putting together to need one? I ask because the 3800 SC should have fueling covered. I mean whatever ECM is used to run the engine would have the fuel tables to handle the extra fuel under boost. The rising rate boost referenced FPR would be best on a car that did not have the ECM programmed for boost and used small fuel injectors.

a mic-mac engine ... a 3400 bloc, with 2.8 HO iron head, Vortech V1 superchager. 1227730 ECM with digital EGR and DIS . I will try to use 3800 Gen I SC injectors. I dont think I will need one but I take informations here an there in case. I want to be the more "street legal" as possible without compromising reliability and staying in acceptable emission level.

With the #28 injectors for 200HP I dont think I will need this regulator. But for now I just have #24 3.4DOHC injectors on hand to put in the project.

[This message has been edited by perry rhodan (edited 10-08-2007).]

quote Originally posted by perry rhodan: a mic-mac engine ... a 3400 bloc, with 2.8 HO iron head, Vortech V1 superchager. 1227730 ECM with digital EGR and DIS . I will try to use 3800 Gen I SC injectors. I dont think I will need one but I take informations here an there in case. I want to be the more "street legal" as possible without compromising reliability and staying in acceptable emission level. With the #28 injectors for 200HP I dont think I will need this regulator. But for now I just have #24 3.4DOHC injectors on hand to put in the project.

You will need to tune and it just gets back to programming. If you are using the popular 730 ECM invest in the equipment -a good prom editing program like Tunercat, an eprom eraser, a eprom programmer some spare eproms and carrriers. Everything should set you back about $500. You will then have the flexibility to customize the fueling and timing to achieve optimum power. There is no easy way to tune EFI without programming the ECM and many onlines sources of tech info are there to guide you towards tuning properly. It is not hard to tune and the process can be learned in fairly short order.
BTW #28 injectors should be good to support over 400HP.

------------------
87GT 3.4 Turbo- 0-60 5.2 seconds
2006 3800SC Series III swap in progress
Engine Controls, PCM goodies,
re-programming & odd electronics stuff
" I'M ON THE LOOSE WITHOUT THE JUICE "

I will retain the service of GM Tuner (Sinister performance) for the ECM tuning.

24lbs injectors and the 7730 should be more than adequate for low boost. The RR FPR shouldn't be needed IMHO.