CJM Mini FP Gauge Kit

jwick

This is always good practice.

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'10 G37T 6MT Graphite/Graphite - BP - G37T Build

phunk

Agreed, always good practice to be aware of your excess teflon tape. We only want it on the threads, not inside the plumbing.

Oh, and partly on-topic, for those who didnt know... stop using teflon tape on AN flare fittings! AN flares seal on the 37 degree flare, not the threads. AN O-Ring fittings seal on the o-ring against the receiving chamfer. AN washer fittings seal on the washer. Basically, straight threads = no tape, and tapered threads = tape. I am trying and cannot think of any application where straight threads are expected to provide the seal... and if the threads are not expected to seal, then no need for thread sealant.

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Chuy

Just got off the phone with Charles, awesome guy to talk with made me want to spend more money. Just FYI they do not have any raw billet mounts till next week. They have plenty of anodized ones.

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Miko 2015 Nismo Tech: nothing

RIP Ginger 2009 370Z Sport Touring

jwick

Phunk. What fuel pressure should we look for idle cruising and say 10lbs. Still running the stock rail

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'10 G37T 6MT Graphite/Graphite - BP - G37T Build

phunk

it should actually have 52 psi 100% of the time if you are not running a return fuel system.

if you have upgraded the fuel pump, it wouldnt be strange to see a little pressure spike at idle. if the idle pressure spike is really high, there are ways to correct it. A spike of up to 6psi or so at idle I would ignore since the o2 feedback will be able to handle this. Past that, I would consider making some modifications if there are issues with consistency in idle A/F.

it also wouldnt be strange to see pressure fall a few psi towards redline on boosted cars as restrictions in the factory plumbing start to become noticable. Since the regulator is before these restrictions, the regulator doesnt see the pressure drop or react to it. This is one of the reasons for a RFS and putting the regulator up front. More than 4-5psi of fuel pressure drop is where i would strongly consider upgrading the fuel system. Fuel pressure drop means you have reached the edge of the existing fuel system, and the edge is unpredictable and inconsistent, and some days the drop could be quite greater than others and start causing big problems in the A/F ratios near redline.

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jwick

Ok so got the gauge installed. Here's what I'm seeing on the first run.

Idle/cruising car warm - 4.3-4.4 kPa (62 - 64 psi)

Idle/cruising car cold - 5ish kPa (72 psi)

Boosting car warm - 3.5 - 3.8 kPa (51 - 55 psi)

It appears I'm consistently running 10psi high

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'10 G37T 6MT Graphite/Graphite - BP - G37T Build

phunk

that is an example of a unhealthy fuel pressure curve. a side effect of upsetting the balance in the fuel pump module by putting a larger pump in without making the proper modifications to accommodate the much higher bypass fuel volume.

your fuel pump is overwhelming the regulator and/or venturi passages behind it. i am guessing you have larger than a 255lph in there to see as high as 72. the canister fill venturi on the bottom of the fuel pump module can be opened up a bit to bring your pressure back down. (this can serve as a reminder to me to work more on my (not-yet-so) "ultimate fuel pump" thread.

the pressure comes down when you start burning more of the fuel because there is less volume that the regulator has to relieve, and backed up pressure from the venturi blockages begins to lower

so the issues are correctable. if your A/Fs are staying inline, there is no immediate rush to resolve it.

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jwick

I'm running the 340lph. AFRs are pretty good. Closed loop I stay between 14.7-15.2. Open loop I'm mid 11's under load. It goes a little rich if I apply throttle a real low rpms (like being in 2nd under 1500 rpms and accelerate in traffic). It clears up almost immediately.

Since AFRs are pretty good I figured I would wait until the S1 upgrade. Will that fuel return setup completely fix my issues? Or will we need to discuss other fixes?

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'10 G37T 6MT Graphite/Graphite - BP - G37T Build

phunk

Ah yes when I did the 340 pump originally I also saw the very large idle spikes. Drilling out of the canister fill venturi to just over 100 thousandths brought it down somewhere into the 50s which was good enough for me.

S1 system will help promote a healthy curve as you go up in power/boost... but the current idle pressure spike you have is a side effect of the pump and the fix for that is unrelated to the RFS upgrade. The RFS will still run the venturi's so the venturi flow has to be opened up a little to fix that idle spike.

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jwick

I'll admit I'm not absolutely sure what you are referring to being drilled. Do you offer an upgraded tube that wouldn't require drilling? The thought of doing something not reversible leaves me a little uneasy.

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'10 G37T 6MT Graphite/Graphite - BP - G37T Build

COSMO

I drilled mine out to 101-thousandths. Have a pic if you want to see?

phunk

It is a little plastic venturi that attaches to the bottom of the fuel pump module. Unfortunately this little guy is not available purchased separately... so there is no going back if you went back to stock.

To put a stock fuel pump back in there with the oversized venturi would weaken the over-tank siphon and promote fuel starvation.

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phunk

COSMO has a picture as I recently had him do it for his pump. I will also try and get this added to my fuel pump thread quickly.

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jwick

Sure. Send it my way

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'10 G37T 6MT Graphite/Graphite - BP - G37T Build

COSMO

Must have deleted it off of my phone but Charles has a pretty good pick of it.. Sorry