What Should I Set FPR to?

[TSITuner4Lyfe69]

ok im gonna run 18psi is this a safe setup? but Whats should i set my FPR at?
evo 3 510cc injector
16g
255lph walbro
universal ajustable fpr *********(what should i set at?)****************
ported evo 3 manifold
megan racing 3inch downpipe
o2 dump
3inch PVC intake with K&N filter

 

[SBR Joe]

Not to hijack your thread but "joe" not that i didnt ask you enough today ...email... with my set up havin the FPR set @ 45 be good runnin about 24 psi

With proper tuning, yes.

Im not tellimg everyone with an FPR to crank it up to 45 psi of bfp. If you have a set of 550's with no tuning and crank it up to 45 psi it will make your rich condition even richer, i didnt make that very clear with my first post. Eventhough you shouldnt have the large injectors with nothing to control the fuel with anyways, but you will need to have something for tuning if your going to run that fuel pressure (45 or more)


Joe

 

[Splitpi]

Joe,

Like i told you today on the phone the car is not running and wont be running for a while yet. I have the Innovate LM-1 and will be purchusing DSMLINK here shortly. So ill have everything i need to adjust fuel and compensate for the 950's.. Just looking for a base setting to start from when i get to everything installed. Just wanted to clarify before i had someone jump on me for it

If you own DSMLink, why no make use of the forums and the DSMLink community?

baseinjectordata [ECMTuning - wiki]

Starting spot (assuming stock fuel pressure and a 2G):
950's = -53 Global, 330 dead time

You can calculate the Global via this equation:

Global = ((old Injector Size) / (New Injector Size)) / (SQRT( New Fuel Pressure / Old Fuel Pressure)) - 1.0
Global = ((450/950) / SQRT(43.5/43.5)) - 1 = (0.4737 / 1) - 1 = -0.526% = -53%

Also if you have an Adjustable FPR, set it via DSMLink. Have DSMLink turn on the fuel pump (With engine off). Measure the pressure and adjust to the correct value. Have DSMLink turn of the fuel pump. Prest'o chang'o without having start the car or pulling a vacume line.

Also I notice your a 1G, so if you set to 36-37 that is fine aswell, and the values above remain the same, still use -53% for the global. The injector just flow less due to the decrease pressure (which is not necessarly wrong either). Basically 950 cc's run at 1G fuel pressure would equate to 881 cc's run at 2G fuel pressure.

@OP-TSITuner4Lyfe69
Set your base fuel pressure to 36-37 psi and put your stock injectors back in. Otherwise, set your fuel pressure to 36-37 psi and get an SAFC and pull -12% from the global settings if you insist on using the 510's. Also, rewire your fuel pump if you plan to use the 510's.

 

[IceMan526]

Not trying to hijack the thread but what is the purpose of removing the vaccum line and plugging it?

 

[Splitpi]

Not trying to hijack the thread but what is the purpose of removing the vaccum line and plugging it?

Stops the AFPR from following the boost/vacume. The FPR is a 1:1 ratio, meaning for every 1 psi of boost, the fuel pressure increases 1 psi aswell above the base fuel pressure.

To measure the fuel pressure, the fuel pump must be "ON", to turn "ON' the fuel pump you must start the car. When you start the car, it idles with negative Vacume. With 1:1 ratio fuel pressure is lower than base (inaddition it "could be" dangerous to start the car with a horribly wrong FPR setting) so you will have the wrong values if you set it this way. So you disconnect the vac line and fpr reads ambient pressure and no longer follow the engine. Makes sense?

DSMLink allows you to turn on the fuel pump with out starting the car. Thus you wouldn't need to disconnect the vacume line since the engine is off.

 

[SBR Joe]

Joe,

Like i told you today on the phone the car is not running and wont be running for a while yet. I have the Innovate LM-1 and will be purchusing DSMLINK here shortly. So ill have everything i need to adjust fuel and compensate for the 950's.. Just looking for a base setting to start from when i get to everything installed. Just wanted to clarify before i had someone jump on me for it

Ok, yeah for your case id set it at 45 psi and itll be all good. I was just stating that fact for the simple fact that someone out there might have 650s, 255 pump, 2g maf, afpr and no tuning...and they see me saying to crank it up to 45 psi and it barely runs. That wasnt directed at you, just a CYA kinda thing. Youd be ok though, 45 psi.


Joe

 

[HighBoostLaser]

ok so read my mods list i have dsm link and 255lph and a cheap ebay fpr all installed should i bee fine now if i tune with dsm link?

 

[snowborder714]

You should really get an MBC and possibly a wideband O2.

But you need to make sure you have no boost leaks and that your timing is correct before you start tuning.

 

[HighBoostLaser]

i have a hahlman boost controller

 

[Splitpi]

Set your fuel pressure to 37.5 psi . Tune from there.