Fuel Management + Boost Control

[Pornflakes]

Not for a Z32 MAFS. In addition, why do you want to go with 72lb injectors? This number seems a bit large for the application (T3/T4), not saying you are wrong in doing so just curious.

The 72lb injectors are not too large at all. With the 50lb injectors I max out at 14PSI with a T3/T4 (95% injector duty cycle).

With the 72lb injectors it maxes out at 20PSI.

96lb injectors will merely reach the full potential of a large trim T3/T4.

If you want to squeeze more fuel through the 50lb and 72lb (even the 96lb ) injectors, you'll need an adjustable fuel pressure regulator, such as the Vortech FMU or Vortech Super FMU (my favorite) to raise the fuel pressure in the fuel rail. Other brands will also work as long as they have the same function.

Then, you can use your S-AFC to fine tune the MAF voltage (and therefore the fuel supply) in order to get the proper A/F mixture (i recommend doing it on a dyno for safety)

[S13Ka24e]

Jay ran 30psi with 72lbs. I mean you just can't say at 14psi 50lbs are maxed because i know people running 10 psi on 370cc. You have to look at each car and the other modifications they did to it. But if you find the therotical HP for 72lbs you get around 450hp now i'm not saying that you didn't reach max duty cycle at 20psi i'm saying you must have been making atleast 400hp at 20psi. Jay on the other hand put down 412hp at 30psi so it is the difference in motors.

[S13Ka24e]

Not for a Z32 MAFS

I think you are wrong, i think that you need a retune for the z32 maf as well. It is really not that big of a deal i mean if you are doing this from the start then you just tell them when you are ordering what maf to tune it for.

[hannibal]

I'm still wondering about MAFs, ECUs, and piggybacks. Check out the end of this thread...

http://www.nissaninfiniticlub....18210

Its sounds like you gotta have a retune to use the Cobra MAF. But can you use the Z32 MAF with a piggyback, or is a retune required as well?

Jay

[Maeda]

you can use the Z32 maf with a piggy back and no retune!

matt another option would be to use the greddy map sensor with the emanage + profec e-01

the you dont need the z32 maf... and can run the stock with the greddy map suppilimenting... just an idea

[Pornflakes]

Jay ran 30psi with 72lbs. I mean you just can't say at 14psi 50lbs are maxed because i know people running 10 psi on 370cc. You have to look at each car and the other modifications they did to it. But if you find the therotical HP for 72lbs you get around 450hp now i'm not saying that you didn't reach max duty cycle at 20psi i'm saying you must have been making atleast 400hp at 20psi. Jay on the other hand put down 412hp at 30psi so it is the difference in motors.

Yah, but you forgot that Jay uses a fuel pressure riser (Bosch fuel pressure regulator) to increase fuel rail pressure. This is the reason he gets 30psi with the 72lb injectors.... There is no way he would get that with stock fuel pressure.

[S13Ka24e]

Yah, but you forgot that Jay uses a fuel pressure riser (Bosch fuel pressure regulator) to increase fuel rail pressure. This is the reason he gets 30psi with the 72lb injectors.... There is no way he would get that with stock fuel pressure.

I did not know he had a Bosch fuel pressure regulator. What was his fuel pressure set at? Anyways you said 20 psi were max for 72lbs, he must have been running more boost than 20 psi if he was able to run 30 psi with just adding a fuel pressure regulator.

As far as what i said about the z32 maf, i thought you were saying that you don't need a reture or a piggy back. Yes you have to have one. The way a piggy back leans out it is changes the signal from the maf so with that you can use that to adjust it. But if you are already going to get a jwt retune you might as well tell them to reture for the z32 maf because it will be easier to tune.

[klattr1]

plenty of people have run the 50lb injectors up to about 17 psi. Guy had turbo KA with t3/t04e in San Diego and ran 50lb'ers up to 18 psi. Chris May used to have 50lb injectors and he ran all the way up to there also. The 4 bar fuel pressure cobra mafs/50lb injector program will allow for this.

[matt0941]

I don't know much about the fuel pressure regulators. What deems the necessity for an aftermarket fuel pressure regulator? If I were able to run a cycle of say 90% at my maximum boost limit on 370cc injectors, would I be ok? Basically what I am getting at is what requires the use of a regulator?

[Pornflakes]

[quote=" klattr1 plenty of people have run the 50lb injectors up to about 17 psi. Guy had turbo KA with t3/t04e in San Diego and ran 50lb'ers up to 18 psi. Chris May used to have 50lb injectors and he ran all the way up to there also. The 4 bar fuel pressure cobra mafs/50lb injector program will allow for this. [/quote]

Maybe I have a very efficient T3/T4 combination then, because mine SURE max out at 14PSI Maybe these guys you heard of use an aftermarket fuel pressure regulator?

Also, the 4 bar program from JWT requires the use of an aftermarket fuel pressure regulator, hence the 4 bar pressure instead of the stock 3 bar. And please note that I max out 50lb injectors at the stock 3 bar fuel pressure.

[S13Ka24e]

Pornflakes -Thanks for the info, you must have a hell of a car. Good luck!

[Pornflakes]

I don't know much about the fuel pressure regulators. What deems the necessity for an aftermarket fuel pressure regulator? If I were able to run a cycle of say 90% at my maximum boost limit on 370cc injectors, would I be ok? Basically what I am getting at is what requires the use of a regulator?

You need an aftermarket FPR if you want your current injectors to flow more fuel than they are currently flowing with the stock FPR. In other words, you can keep your current injectors and raise the fuel pressure instead of buying larger injectors (to some extend of course).

Fuel goes from the tank to the fuel rail, through the FPR, back to the tank. The FPR only lets a cetain amount go back to the tank, thus keeping a certain pressure in the rail. What an aftermarket FPR does is that it lets EVEN LESS fuel back to the tank, thus raising the fuel pressure in the fuel rail even more.

You have a water pipe holding 30PSI of water pressure. You open the valve (injector) for 1 second and shut it, and you'll get X gallons of water out of that period. You have the same pipe holding 40PSI of water pressure now, open the valve for the same 1 second and you'll get more water out than you did at 30PSI.

Hope it helps a little

[Pornflakes]

Pornflakes -Thanks for the info, you must have a hell of a car. Good luck!

Anytime buddy.

I can't complain about my car. What can I say...I'm in love :pface

[VQdriver]

You don't have to get a upgraded MAF to use the JWT ECU. But if you upgrade your MAF, you will need the JWT ECU(or a standalone) to read the new MAF properly.

Injectors72 lbs/min = 756 cc/min

the conversion formula is:cc = lbs x 10.5

Jay

what brand of injectors do you guys prefer for such a large application? what fuel rail would you combine with that brand of injector? would it be correct to say that the JWT ecu combined with SAFC, AVC-R will produce the numbers i'm looking for after the fuel modifications?

[hannibal]

I just learned that only the Cobra MAF requires a ECU retune. The Z32 MAF can be run with a just a piggyback.

[C-Kwik]

I just learned that only the Cobra MAF requires a ECU retune. The Z32 MAF can be run with a just a piggyback.

Yes, but essentially you can do that with a Cobra MAF as well. But A piggyback like the E-Manage already has the known airflow values for the Z32 MAF and the S14 MAF so it retunes the fuel curve for you based on these known values. And it's as easy as a mouse click away on the E-manage. If you wanted to run a Cobra MAF, then you would need to either find a Nissan MAF a similar voltage/airflow curve or input the adjustments in the tuning maps to compensate.