Page 1 of 2
FUEL PRESSURE REGULATOR
Posted: 2022 Aug 08, 14:19
by jgomez
HI
WHAT GASOLINE PRESSURE SHOULD THE MECHANICAL REGULATOR INDICATE WHEN IT IS ON? AT IDLE
Re: FUEL PRESSURE REGULATOR
Posted: 2022 Aug 08, 14:54
by decipha
on a stock lightning/harley with stock fuel pressure regulator it should be around 32 psi at idle and should jump up to 40psi with the vac line removed.
Re: FUEL PRESSURE REGULATOR
Posted: 2022 Aug 08, 19:37
by jgomez
decipha wrote: ↑2022 Aug 08, 14:54
on a stock lightning/harley with stock fuel pressure regulator it should be around 32 psi at idle and should jump up to 40psi with the vac line removed.
well i have some mods
ported heads
long headers
bigger crank pulley (+6lb)
single blade throttle body
intake K&N
injectors 47 lbs
pistons and connecting rod forged
among other minor
so what pressure it shoulb be at idle and with the vac line removed?
thanks
Re: FUEL PRESSURE REGULATOR
Posted: 2022 Aug 08, 21:23
by decipha
If I were to tune it then I would set it to 60psi base pressure
if its already tuned though you have to set it to the pressure the tuner tuned it at.
47s are a waste stock is 42
best bet is 80lb minimum
Re: FUEL PRESSURE REGULATOR
Posted: 2022 Aug 08, 23:40
by jgomez
ok thanks so much i gonna do the change
one more think whats do you mean "set it to 60psi base pressure"
with the vac line removed or with the vac line on?
thank you for help me
Re: FUEL PRESSURE REGULATOR
Posted: 2022 Aug 09, 05:37
by decipha
base fuel preasure can only be set with the vac line off
http://efidynotuning.com/inj.htm
Re: FUEL PRESSURE REGULATOR
Posted: 2022 Aug 10, 17:00
by jgomez
decipha wrote: ↑2022 Aug 08, 21:23
If I were to tune it then I would set it to 60psi base pressure
if its already tuned though you have to set it to the pressure the tuner tuned it at.
47s are a waste stock is 42
best bet is 80lb minimum
ok then set the base pressure to 60 psi with the 47lb injectors.
It will take me a while to have the 80lb but when I have it, what base pressure should I have on the regular?
The other question, how do I tell the pcm that the base pressure is now 60psi? I am using ADVANTAGE III, what parameter should I change?
I attach some images to know if it is any of those parameters
Thank you very much for your help and above all patience.. I'm doing my own tune
Re: FUEL PRESSURE REGULATOR
Posted: 2022 Aug 10, 19:31
by decipha
you can 40 psi base with the 80s no prob or 65psi if you plan on making 800rwhp
read the fuel write up on the homepage
you have to download the injector data sheet for your injectors and then interpolate all the deltap multipliers for 60 psi
come up with all the actual values and then set the high slope in the tune to 30 lbs/hr
then take 30 and divide your actual high slope that becomes your scaling percentage
apply that to all your actual injector values other than the offset and plug that in to your tune
apply the scaling percentage to the actual maf transfer and transient fuel too.
Its covered in the fuel write up.
btw sct sucks for the eec's (2004 and older). Youd be far better off getting a quarterhorse.
Re: FUEL PRESSURE REGULATOR
Posted: 2022 Aug 10, 20:32
by jgomez
decipha wrote: ↑2022 Aug 10, 19:31
you can 40 psi base with the 80s no prob or 65psi if you plan on making 800rwhp
read the fuel write up on the homepage
you have to download the injector data sheet for your injectors and then interpolate all the deltap multipliers for 60 psi
come up with all the actual values and then set the high slope in the tune to 30 lbs/hr
then take 30 and divide your actual high slope that becomes your scaling percentage
apply that to all your actual injector values other than the offset and plug that in to your tune
apply the scaling percentage to the actual maf transfer and transient fuel too.
Its covered in the fuel write up.
btw sct sucks for the eec's (2004 and older). Youd be far better off getting a quarterhorse.
ok im going to read about fuel on the homepage...so if sct sucks what tuning program do you recommend me?
Re: FUEL PRESSURE REGULATOR
Posted: 2022 Aug 10, 20:38
by decipha