The main line is also a 5/16 or metric equivalent in the 370z. There are many places inline the plumbing of much smaller size, and much larger size. This makes it hard to use any type of math to determine flow/drop etc across the *entire* system. But you could surely calculate flow through just the hardpipe itself pretty accurately, just sort of estimate the bends. Just remember to compensate for wall thickness. Hardpipe sizing is always based on the OD.. as the OD of the hardpipe is to match the ID of softlines.

I cannot speak for them... but the appropriate weapon in such a battle is information.

They will have to do a little more testing before the culprit can be precisely located. You wouldn't want to just throw parts at it... that is no way to go about it when trying to make an engineered and cost effective retail product. They need to know exactly where the source of concern is, so that it can be dealt with accordingly.

With more information they can determine exactly what combinations of fuel system upgrades will be included or recommended with the incremental stages of their kits.

:iagree: I was thinking the EXACT same thing!:rolleyes:

We are using a 340lph or something in this range and larger injectors than the traditional 600cc. On behalf on everyone from F.I, thank you! :tup:

This is exactly the way we are approaching the issue!

Great info!
My only concern is how much of an issue is this if so many boosted 370s are out there and STILL out there and I can't think of much that have blown motors. There's some over 10k miles and still running. I'm at 6k n have had no problem whatsoever.
Is this really an issue or is it being taken overboard? Losing fuel at the top end would be disastrous and for boosted 370s n g37s to have been running on the road for so long with no fuel issues seems like it's not a real problem at all.

In the end it's still a great build and the attention to detail is very nice.

Well you have to look at it for what it is. I have a lot more miles than you and have not had a problem either. However, that does not mean my car isn't experiencing any fuel pressure drop.... and to not have a blown motor does not mean I dont have it. If my car has it, then I tuned around it, and I didnt even know. Thats not clean, pro, or consistent... but its my own car and im not trying to sell it to anyone.

Pressure drop, being that it occurs when part of the system is operating at 100%, means its profile can change from the slightest difference in environment.

If your car has pressure drop, and a canned tune youre running was built on a car with pressure drop... well then its going to be pretty close and you might never experience a problem. However, it leaves room for the unfortunate guy who just happens to have the wrong combination of environmental conditions to cause the pressure curve to go rogue enough and cause potential engine damage. An EMS tune on the stock computer has no way of compensating for fuel pressure swing on its own... so it can be tuned around, but if that swing moves at all, the tune is no longer good for that pull.

Thinking back... my A/F in my 370z isnt all that consistent. Some pulls im leaner or richer on top than others. I always just attributed it to the fact that I am a noob with the UpRev, or that I run E85 which is hardly consistent. The fact is that my tune is conservative enough that I have plenty of room for error.

But... on the wrong day and the wrong tank of gas, the variables could overcome the conservative buffer in my tune and BOOM.

Maybe my inconsistencies have more to do with fuel system inadequacy than my tune or selection of fuel. Never checked!

Information is boss.

Just to clear things up.. the car is not technically leaning out, you can see that in the AFR on the dyno graph. It is safe to drive and would probably run great as is for a long time however, it is not something you want happening. Im really curious if anyone else has ever installed a fuel pressure gauge

^^ exactly. dropping fuel pressure can be tuned around all day for safe A/Fs, so long as the pressure doesnt drop too low for the power and injector size. Its very possible that is the scenario occurring in my car and many other boosted Z's.

Has anyone else actually monitored fuel pressure at the rails above 500whp?

Funny guys ... U didn't know chit !!

Vince@ R/T Tuning did so Charles when I was getting my built motor tuned with your fuel return system 850cc injector's DW 300 pump.My car was dropping fuel pressure over 500whp. I don't remember how much but I ended up leaving my car there to have your twin pump's installed fuel lines and rails installed, I know Vince spoke with you a few times while he was working on my car.

You just kicked the problem straight out of the ballpark, which is respectable for sure, and often times cost effective on an individual build basis. R&D for a single car project can be more hassle than just going the route you did and washing your hands of any potential problem areas.

But it will be interesting to see what F.I. may find as to sources of the restrictions. Naturally, a full twin pump with rails kit may be cost prohibitive for many customers. So there should be some value in finding this information.

I have had intentions of building a full custom test bench for this stuff. I need to find an electrical engineer who can help me with a schematic on a custom injector driver with adjustable power source output, realistic firing order/sequence for 4 6 and 8 cylinders, adjustable simulated RPM, and pulsewidth. Anybody? Bueller?

:wtf2:

What my shop did on the G37 was use the factory fuel supply line as the return line, and built a whole new fuel line for my twin pumps. Problem solved :)

I have read in other forums that installing inline fuel pump will help to keep the fuel pressure steady at high PSI of boost,

Why nobody tried that on this car yet?