Fuel Pressure - Page 2 - Tuning Forum

Forum Post / Reply
You must log in before you can post or reply to messages.
Re: Fuel Pressure
Tuesday, January 17, 2012 4:07 AM
SLO CAV (autocrossing dude) wrote:

Addicted to meth wrote:


the "vacuum" reference is pre-throttle body on the J-bodies

Depending on how you look at it.

on a LD9 it is on the TB, which depending which port could be considered after the TB.

Usually on Eco's we connect it to the intake manifold.

With the M45 it is also on the charger (boost side).


The stock FPR is actually a 1:1 FPR that will increase fuel pressure 1 psi for every 1 psi of boost

I'm glad you posted this. I have also known it to be this way, or read it was. Others say it is not.

If you want I can make a video showing that infact it is boost referenced I have electronic auto meter pressure guage and it does add 1:1

I think it would be a good idea to show proof.

FU Tuning

Re: Fuel Pressure
Friday, January 20, 2012 8:03 AM
EvoFire wrote:

Would it be safe to bump the fuel pressure up to 60 at idle (w/vacuum) to get 42 lb/hr ratings outta the injectors? this would allow the injectors to deliver more fuel per pulse and should help me lower my IDC. Am I thinking about this right?

I just wanted to add that the GM kit injectors are not rated at 36lb/hr. These are the specs I got straight from Delphi.

Injector Type: Long
OEM  (ETCH)  Part Number: 12593904
Delphi PN (if different from etch): 25334059
OEM Application: HPSC L-850
SPO Ref - Delphi order P/N: 12593904
Max Flow (gms/sec): 4.15
Supply Pressure (Kpa): 350
Impedance: high
Max Flow (lbs/hr): 33
Supply Pressure (PSI): 50.8

Manufacturing Location: CPV
Spray type: Single
Separation angle: n/a
Cone Angle: 10

So these Injectors rated at 60psi will get you about 36lb/hr if these were the injectors you are talking about.

Are the injectors see boost on the end thats spraying into the engine? So if your producing 10psi boost pressure, does that cancel out the extra 10psi at the fuel rail if the FPR is 1:1?

Save your money. It might be worth something someday.

Forum Post / Reply
You must log in before you can post or reply to messages.


Start New Topic Advanced Search