adj fuel pres reg + fmu for blower?

grey302

New Member
Aug 2, 2003
41
0
0
Reidsville, NC
i am running a 9psi supercharger with a 255lph fuel pump and the fuel management unit for the blower. my question is whether or not to keep the fmu connected after in install the kirban adj pressure regulator i just bought?

do i run both, or just the kirban regulator? also what is a good base psi to set the regulator on to start with?
 
  • Sponsors (?)


i have about the same qustion ? i got 24# injectors,10# boost and bbk adj fuel press reg the most fuel press i can get is 33 @ idle it just dont seem like enuff pressure but i get no ping. i think be 4 i put 255 in tank pump i could get about 40@ idle with t-rex inline and stock pump is it the FMU should i ditch it ??????????
 
when running a blower the IDEAL way is to ditch the FMU and get larger injectors that can feed the engine on their own without relying on the FMU, and getting a custom tune so the car will run good.
 
dont worry about the pressure now. i'd get AT LEAST 42s, get the car tuned. with a properly tuned car you will run factory fuel pressure (39-40) this is how the injectors are rated and the tune is going to tell the EEC that it had 42s now and if the FP is jacked up the injector will be flowing more than 42lbs and the EEC will try and compensate and lean out the mixture (at least in CL). running stock FP makes sure the injectors are close to flowing their actual 42lbs per hour.
 
So 42# injectors and maf to match injectors and ditch FMU get a tune good to go correct? so could i get by without a tune 4 a while if so set fuel pressure @ what factory about 40. thanks 4 your help!
 
If you do not have 42lb injectors and a tune you need to run the FMU.
The FMU increases your FP when you are into boost.
Just running a FPR will not provide you with enough fuel pressure to accomodate the boost.
 
So 42# injectors and maf to match injectors and ditch FMU get a tune good to go correct? so could i get by without a tune 4 a while if so set fuel pressure @ what factory about 40. thanks 4 your help!

i'd get a custom tune to go along with it. the car will run but may run like crap. i wouldnt get on it or anything with it like that. you will NEED a tune to get it to run correctly and know its in a safe AFR range.
 
i ran 12#'s 42 inlectors 80mm mass air and an power pipe with no tune and i took it to the dyno and the af was pretty much dead nuts 12:1 little rich down low but up top perfect. I also had a lot of bas timing in the car as well.
 
grey302 said:
i am running a 9psi supercharger with a 255lph fuel pump and the fuel management unit for the blower. my question is whether or not to keep the fmu connected after in install the kirban adj pressure regulator i just bought?

do i run both, or just the kirban regulator? also what is a good base psi to set the regulator on to start with?

Definitely keep the FMU. It works by increasing pressure by shutting off the return line. Without larger injectors, it'll be detonation city. The regulator would have to be turned way up in order to work as a substitute for the FMU. Start at the stock 39-40psi with the vacuum line disconnected.

ybrik said:
why can i only get 33# max @ idle now? THANKS!

If you pull the vacuum line off, it should come up. The fuel pressure regulators increase pressure as manifold vacuum decreases, so it will show full pressure once the line is off.
 
I did pull vac line off regulator . and turn cw (screwed in all the way) i get 33# @ idle and turn ccw it starts dropping. regulator is suppose to be adj from30#-70#. I think accel is shat. I'll try a bbk. First i check FP @ filter then work my way up.Some of you say to get 42# inj but im pretty close to stock w/ Vortech S trim @ 10#, Trickflow up n low intake . also my FMU is calbr for 24# injectors
 
I did pull vac line off regulator . and turn cw (screwed in all the way) i get 33# @ idle and turn ccw it starts dropping. regulator is suppose to be adj from30#-70#. I think accel is shat. I'll try a bbk. First i check FP @ filter then work my way up.Some of you say to get 42# inj but im pretty close to stock w/ Vortech S trim @ 10#, Trickflow up n low intake . also my FMU is calbr for 24# injectors

Get a Kirban or Aeromotive regulator.
Definitely NOT a BBK.