adjustable fuel pressure regulator
07-20-2006, 08:29 AM
#21
Originally Posted by dewmanshu
I think you guys are right, but I could of sworn alot of guys were having issues with the radix and the non-return system of 2003. Hmmm. Let me do a quick search. I am probably wrong on that, cuz everything is always 99 to 03 in references. BlownChevy would certainly know as well.
07-20-2006, 08:40 AM
#22
Originally Posted by Z06 DREAMING
As far as I know 2003 was the return style fuel system.
Sorry for the bad info. Ugh.
07-20-2006, 10:18 AM
#24
Found this info on Summit Racings site about the Vortech FMU...
"Increase fuel pressure according to boost.
These Vortech Standard Fuel Management Units are designed for use on multi-point fuel injected engines. They are secondary fuel regulators that install in series with a stock regulator on the return line to the fuel tank. The units increase fuel pressure in proportion to boost pressure (assuming that the pump being utilized has sufficient pressure and flow to deliver the fuel required). "
By using one of these we should be able to tune the truck so that it will run almost "stock" fuel ratio when not under boost for maximum MPG but, have all the fuel it needs during boost, right?
"Increase fuel pressure according to boost.
These Vortech Standard Fuel Management Units are designed for use on multi-point fuel injected engines. They are secondary fuel regulators that install in series with a stock regulator on the return line to the fuel tank. The units increase fuel pressure in proportion to boost pressure (assuming that the pump being utilized has sufficient pressure and flow to deliver the fuel required). "
By using one of these we should be able to tune the truck so that it will run almost "stock" fuel ratio when not under boost for maximum MPG but, have all the fuel it needs during boost, right?
07-20-2006, 11:11 AM
#26
Guys, FMU are considered a bandaid approach to add fuel mechanical while in boost mostly for motors with computer that can't be tuned. They increase fuel pressure per pound of boost so that the injector squirts more fuel for the same amount of opening time. They really make the fuel pump work HARD. Think about this, A 10:1 fmu is increasing fuel pressure 10 psi for every 1 psi of boost. So at 6 psi of boost, that 60 psi of fuel pressure . Add that to the 58 psi it's already at and your fuel pressure is now 118 psi 
. Think if your running 10 psi of boost . Do you really want to run that much fuel pressure, when you can easily get better results with tuning the computer to add fuel like its supposed to? I messed around with FMU's on a 2.8 TBI S-10 I turboed. It was a pain to tune, because I had to "bleed" boost pressure to the fmu to try to get the fuel pressure where it needed to be to get the fuel right for boost. Most tuners will not even mess with a FMU if the is a viable option for tuning like are trucks have with EFILive and HPTuners.
All you really need is a vac/boost vef fuel pressure reg that will raise fuel pressure 1:1 like what these truck came with from the factory until 04, so the injectors think they are still squirting in to 1 atmosphere. The return-less fuel system is a little harder to tune and won't go as far on injectors, as the return style, but it still works, just have to upgrade to 60's sooner
.
. Think if your running 10 psi of boost . Do you really want to run that much fuel pressure, when you can easily get better results with tuning the computer to add fuel like its supposed to? I messed around with FMU's on a 2.8 TBI S-10 I turboed. It was a pain to tune, because I had to "bleed" boost pressure to the fmu to try to get the fuel pressure where it needed to be to get the fuel right for boost. Most tuners will not even mess with a FMU if the is a viable option for tuning like are trucks have with EFILive and HPTuners. All you really need is a vac/boost vef fuel pressure reg that will raise fuel pressure 1:1 like what these truck came with from the factory until 04, so the injectors think they are still squirting in to 1 atmosphere. The return-less fuel system is a little harder to tune and won't go as far on injectors, as the return style, but it still works, just have to upgrade to 60's sooner
.
Last edited by kbracing96; 07-20-2006 at 11:16 AM.
07-20-2006, 12:29 PM
#27
Originally Posted by kbracing96
All you really need is a vac/boost vef fuel pressure reg that will raise fuel pressure 1:1 like what these truck came with from the factory until 04, so the injectors think they are still squirting in to 1 atmosphere. The return-less fuel system is a little harder to tune and won't go as far on injectors, as the return style, but it still works, just have to upgrade to 60's sooner .
.
Again, don't worry about an aftermarket FPR until you need to change fuel rails imo. Don't, by any means, use an FMU -- get the correct sized fuel pump imo.
Originally Posted by Lord Aries
By using one of these we should be able to tune the truck so that it will run almost "stock" fuel ratio when not under boost for maximum MPG but, have all the fuel it needs during boost, right?
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