Need more fuel

[can't stop spinning]

A little background first. Right now I'm running RC 750 injectors on my big turbo set up with a return line. With the vac line disconnected my fuel pressure is 50psi. On high boost, I'm a 11.8-12.0 a/f at redline with my dtec at all 0's. So obviously I need more fuel.

What is the simplest way to get my modified walbro to give me more fuel? Larger injectors, bottle neck fix, or pump re-wire? I don't have the time to do the last 2, so which 1 would give me the biggest increase in fuel?

Or is there another easier way to get more fuel?

[SpeedEuphoria]

you dont really need larger injectors, so I would find time to do the last 2

[Gmanigio]

Methanol!!!

100% meth drops my A/F about .8 from 11.2 to 10.4

[Gmanigio]

I would do the re-wire first. How much boost are you running to run out of fuel with returnline AND 750cc?

Your dropping a lot of fuel at idle with 50psi.

When I did the bottleneck mod I ended up having a leak in the system, not a gas leak. ANd my pressure was all out of wack.

[Turbocruiser13]

I'm gonna say BNF and rewire are the most critical things at the moment. A buddy of mine and me have almost the same setup except I have the bnf and he doesn't. At 58psi he's running lean up top on his 650s with 20psi boost. At only 48psi with my 650s and 20psi of boost I'm pulling fuel.

[can't stop spinning]

Quote: Originally Posted by Gmanigio

Methanol!!!

100% meth drops my A/F about .8 from 11.2 to 10.4

I'm already running 100% meth with my direct port kit.

I'm running somewhere from 28-30lbs of boost.

Guess when I get my car back from my buddy who's installing some stuff for me, I'll do the bottleneck fix, as I have most of the parts to do that one.

[Gmanigio]

Quote: Originally Posted by can't stop spinning

I'm already running 100% meth with my direct port kit.

I'm running somewhere from 28-30lbs of boost.

Guess when I get my car back from my buddy who's installing some stuff for me, I'll do the bottleneck fix, as I have most of the parts to do that one.

Wow... I thought 750cc were good enuff for all that power. AND 100% meth!

[duster360]

Quote: Originally Posted by can't stop spinning

A little background first. Right now I'm running RC 750 injectors on my big turbo set up with a return line. With the vac line disconnected my fuel pressure is 50psi. On high boost, I'm a 11.8-12.0 a/f at redline with my dtec at all 0's. So obviously I need more fuel.

What is the simplest way to get my modified walbro to give me more fuel? Larger injectors, bottle neck fix, or pump re-wire? I don't have the time to do the last 2, so which 1 would give me the biggest increase in fuel?

Or is there another easier way to get more fuel?

I have told kids this a million times now,,,,a LEANER A/F does not immediately indicate your fuel system is junk.

You check the Fuel Sytem's capacity ONE way, and ONE way only: Fuel pressure at WOT

If fuel pressure DROPS at WOT then the fuel supply needs upgraded. If the pressure NEVER drops, then pumps, wires, hoses, regulators, ect,,, will ONLY be a waste of time and money.

[can't stop spinning]

Quote: Originally Posted by duster360

I have told kids this a million times now,,,,a LEANER A/F does not immediately indicate your fuel system is junk.

You check the Fuel Sytem's capacity ONE way, and ONE way only: Fuel pressure at WOT

If fuel pressure DROPS at WOT then the fuel supply needs upgraded. If the pressure NEVER drops, then pumps, wires, hoses, regulators, ect,,, will ONLY be a waste of time and money.

I'm in the process of getting a fuel pressure gauge installed right now. However, I wont have my car back for a couple more weeks, so I can't really say what my fuel pressure is at the moment under wot.

I do know that my injectors are maxxed out at the moment though.

So what happens if the pressure doesn't drop? What does that indicate?

[duster360]

Quote: Originally Posted by can't stop spinning

I'm in the process of getting a fuel pressure gauge installed right now. However, I wont have my car back for a couple more weeks, so I can't really say what my fuel pressure is at the moment under wot.

I do know that my injectors are maxxed out at the moment though.

So what happens if the pressure doesn't drop? What does that indicate?

It indicates there's not a damn thing wrong. Its means your injectors are getting every last bit of fuel they need.

How do you know your injectors are maxed out??? Your over 450whp(750cc/min@70psi)??

[can't stop spinning]

Quote: Originally Posted by duster360

It indicates there's not a damn thing wrong. Its means your injectors are getting every last bit of fuel they need.

How do you know your injectors are maxed out??? Your over 450whp(750cc/min@70psi)??

My injectors are at or over 90% duty, I'm pulling 0 fuel with my dtec, and I'm pretty damn sure I'm in the neighbourhood of 480-500hp. My car has enough power to consistantly trap 128-130 on just about any given night.

[duster360]

Quote: Originally Posted by can't stop spinning

My injectors are at or over 90% duty, I'm pulling 0 fuel with my dtec, and I'm pretty damn sure I'm in the neighbourhood of 480-500hp. My car has enough power to consistantly trap 128-130 on just about any given night.

Good,,,,then you need to varify your fuel pressure,,,and if its STABLE,,,go get some bigger injectors. If the pressure drops then a fuel system upgrade is in order and injectors are probably unneccesary.

What are you using to read Duty cycle? A few scan "guages" report false DC, Aeroforce is the usual suspect.

[can't stop spinning]

I'm going off of what my dtec is telling me for injector duty.

But like you said, I have to verify what my fuel pressure is actually doing. Thanks for the advice

[RicanSRT4]

Quote: Originally Posted by duster360

Good,,,,then you need to varify your fuel pressure,,,and if its STABLE,,,go get some bigger injectors. If the pressure drops then a fuel system upgrade is in order and injectors are probably unneccesary.

What are you using to read Duty cycle? A few scan "guages" report false DC, Aeroforce is the usual suspect.

So how much HP can the stock fuel lines can handle??
just want to know before spending $$$ on something i don't need.

[srt4me18]

Im also in the high 90's for injector duty cycle at 25 PSI, 58static, w/ rising rate hooked up, 6- to rail, 4- return, bottleneck fix, took off rewire as it kept failing.... my car should be trapping 128-130, but has yet to do so...