*****Fast Intentions "Twin Turbo Kit" is here*****

F.I. Inc.

You data log what through UpRev? (Fuel Pressure) or Air/Fuel ratio? We are not having a problem with air/fuel, we are dropping fuel pressure. The reason I said most people do not know if fuel pressure is dropping is due to the fact that you cannot monitor fuel pressure through the UpRev software. That being said, please elaborate. How is your fuel system setup? Any feedback will be greatly appreciated.

Thank you, Tony

__________________
Follow us on Facebook: Fast Intentions Inc.
Phone: (805) 522-FAST (3278)
Email: tony@fastintentions.com
www.fastintentions.com
"FUELED BY PASSION"

elperuano

Yes, air/fuel is what I meant. I'm not running lean at all at any spots on my band so there's not a problem with the fuel pressure. If I was losing pressure I'm sure I'd be running lean at spots and I haven't seen any. I know of only 2-3 people I believe that had to upgrade the fuel system but they are built motors.

Boosted Performance

Tony, what size is the fuel pump? I know that the 255lph fuel pumps will run out of steam at 500-550whp (with boosted VQ's). This is why I switched to the 340lph fuel pumps and larger (than normal) fuel injectors.

Dyno sheet is looking good too, keep up the good work.

__________________
750WHP starting @ $7,500 to the door
FOR DETAILS VISIT: http://www.the370z.com/members/boosted-performance.html
FB: https://www.facebook.com/Boosted-Per...6303179791462/
IG @boostedperformanceyeg

TerribleONE

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!

__________________

phunk

Restrictions in fuel system plumbing will cause a pressure drop between the fuel pump and the injectors. Every car will experience this to some degree. The amount of pressure drop between the pump and the injectors will be awfully dynamic and impossible to determine off hand.. you have to do individual testing per application.

At engine idle, or lower power needs such as cruising, there is less fuel flowing through the lines, and the pressure drop will be less. As power climbs, fuel flowing through plumbing in the vehicles starts to increase, and each and every restriction in the fuel system will start to manifest into a sum of pressure drop.

The 370z, in factory configuration, regulates fuel pressure off the side of the fuel filter housing, inside the fuel tank, immediately inline after the fuel pump. What this means, is that the pressure regulating system is regulating pressure at the fuel filter. Before any of the substantial drops in pressure on the way to the engine bay.

If you converted to a return system, you will now be regulating pressure in the engine bay. So instead of seeing pressure drop between the filter housing and the rails, you will see steady pressure at the rails, and pressure increased at the filter housing, to compensate for such the inline drops.

At what quantity of fuel does pressure drop begin in a stock 370z fuel system? There is only one way to find out. Place a fuel pressure gauge off the rails, and place a fuel pressure gauge off the fuel pump. Nobody has done this yet. But only by doing this will someone have completed the R&D to give accurate estimates to how much the 370z fuel system can push, before pressure drop is imminent.

This final number can only be accurately described as a measurement of volume, not HP. However, it would require too much additional R&D to translate this number to a volume of fuel, and then that information would be worthless to the consumer who would be unable to translate that back to a HP figure they can relate to. Injector spray quality, fuel temperature will somewhat effect how much HP you can say the factory plumbing is good for before pressure drop. Tuning and fuel type will *drastically* effect this number. As a couple degrees of timing can go plus or minus 25 HP without changing fuel requirements.

__________________

phunk

Simply because one persons 370z is not flowing enough fuel yet to show a pressure drop between the pump and rails (or so they do not believe, depending on what evidence they have to support this claim) does not mean other cars will not. To make such direct comparisons would be unwise. Example... I have an A/F gauge in my 370z. I have a fuel pressure gauge in the ENGINE BAY... nearly worthless. My car is making similar power to the test vehicle in questions here. Now, I dont THINK my car is dropping pressure... but how do I know? I dont. My A/F is good to redline... but I have 1000cc injectors and my pressure would have to drop quite a bit to not get the quantity of fuel I need. My pressure gauge, being in the engine bay, only allows me to make sure my pressure is correct at idle. For all I know, my pressure might be dropping by 20psi by redline. :shrug: I never had a reason to look! If this test car in question here didnt have an in-car pressure gauge, who knows if they would have even known.

As you reach the maximum output of just about anything in this world, you find that every tiny little detail begins to have massive effects on where the precise maximum is. This is why automotive manufacturers always build their cars to operate systems at much less than 100%. 100% is not reliable, and it is extremely distant from CONSISTENT.

I think that it is great that they are watching the details on this build. While I do not worry about my car blowing up, and I dont worry about their car blowing up... its a very different game when the car is in possession of experienced tuners. They can make sure its not going to break even when pushing it to the limit. BUT, they want to put together a high quality turbo system for the consumer, and some versions of that kit are going to include a tune I would assume. This means they need to watch and log everything within reason to make sure that the tune they build is going to behave the same on their customer's installations.

__________________

phunk

There are 2 options for working around a fuel pressure drop in the system in a scenario such as this, and you can optionally take both steps.

Option 1, increase the plumbing size to reduce pressure drops. This can get expensive depending on how far you take it... because a duration of the conservative sized plumbing is physically built into the inlets of the factory fuel rails. The fuel rails themselves are massive and do not need upgraded... however to cut off the ends and weld on different inlets isnt an option for customers who need bolt on solutions, and welding fuel rails is often prone to pinhole leaks. It just makes more sense to move to billet fuel rails so that its simple to add larger plumbing. Well, this gets expensive now.

Option 2: convert to a return fuel system. For one simple reason, to regulate fuel pressure as close as you can to the rails. How does this help you may ask?

Lets say you have a walbro 255, and you are running out of fuel on top. You might say to yourself... oh, I am running out of pump, so i need to put in a larger pump so that pressure doesnt drop anymore. Well, thats old school thinking... thats what it USED to mean when cars had return lines and regulators in the engine bay.

Because pressure drop. While you might be losing pressure in the engine bay with your 255... you might NOT be losing pressure all the way back up the pump. If you arent, then upgrading the pump isnt going to do a dang thing, because the regulator is still going to be holding open at the same pressure in the back. BUT... if your regulator is in the engine bay, and you still have a pressure drop... a larger pump can actually fight the restrictions by flowing greater at higher pressure. Your regulator in the engine bay can hold pressure where its supposed to, and you just let pressure skyrocket at the pump to keep up, compensating fuel pressure drop across the lines.

Basically all I am saying here, is that nobody can argue unless they have *more than one* fuel pressure gauge in their 370z. You might be surprised if you knew how much fuel pressure can drop from one end of a fuel rail to the other, let alone across an entire car.

__________________

Dzel

Yep what he said

__________________
10secWS6
IF YOU CAN'T SWING IT THEN DON'T BRING IT! Check out Domestic Performance C.C.

sparky

i knew all this too.

__________________
2012 370Z GM 7AT/JWM LEDs / 3M clear bra / 35% tint / GTR start button / FI CBE SS 18" RES / Momo shift knob / K & N Typhoon / Z1 hood struts / H&R 20mm f/r / illuminated kickplates

NeverBoneStck

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

__________________
Juiced! That is all you need to know !!

phunk

LOL I kept it short too Which may backfire if any engineers read that and become displeased with the way I chose to simplify some things.

__________________

Dzel

So what can one do to fix this issue?

__________________
10secWS6
IF YOU CAN'T SWING IT THEN DON'T BRING IT! Check out Domestic Performance C.C.

phunk

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.

__________________

Dzel

I was thinking the EXACT same thing!

__________________
10secWS6
IF YOU CAN'T SWING IT THEN DON'T BRING IT! Check out Domestic Performance C.C.

TerribleONE

This is exactly the way we are approaching the issue!

__________________