well that answers the question then. The SS box can not properly scale much larger injectors than stock.

Go with the eManage.

Also, TS is partnered with PE, so of course they will favor their products. They are correct....PE injectors are better quality and offer better atomization than RC's....but I am not willing to pay twice the price, and put up with difficult availibilty, and sub-par customer service for a slightly smoother idle. That is the only area will you will likely notice the difference on a daily basis.

 

Here is what I don't understand, though.
I know that with the stock injectors at stock pressure, the MAF maxes out, the duty cycle maxes out, etc. Makes sense.

Right now, though, with the current setup, us vortech guys are adding about 8 psi of fuel per lb of boost. At RPM's over say 4500 and boost greater than 3.5 lbs, we are modifying the MAF sensor DOWN. We are telling the ECU there is LESS air and making it SHORTEN the duty cycle.

Right now, we are making this work with more fuel pressure, the obvious other way is with larger injectors. The same situation applies to the ECU. Either with increased fuel psi (like now) or with bigger injectors (like is proposed) we want the ECU to open the injectors LESS than what it thinks it should. We modulate the MAF and injector signal DOWN so that it doesn't max out. (at least as read by the ECU)

The ECU doesn't know when we raise fuel psi and it doesn't know when we increase injector size, right? All it knows is the MAF reading and the corresponding injector pulse width. So what is the difference between increasing fuel psi or increasing injector size with base fuel pressure?

 

Why not "hack" the MAF. I read about it in a 240 forum. For example, the original MAF is 2 inch diameter, the original injectors are 270cc. Now you put the original MAF inside a 2.75in tube, and install some 370cc injectors, the car should run like stock, except for more timing advance. You can then use the SS box to fine tune the car and reduce timing. The advantage of doing this is this will let the MAF measure more air before it maxes out. If you use the SS box to trim the MAF signal down, the MAF will max at under 10 psi. But if you use a bigger diameter tube, the MAF is measuring less air, so you can boost more before the MAF maxes out. Now I know you won't max out the MAF with 370cc injectors, but what if you want 550cc injectors? Just use a tube that's 4 inch diameter and then fine tune with the SS box and reduce the timing. If I can find that thread I will post it later. It explains it better than I do.

 

I couldn't find the original thread, this is another person's attempt on making a hacked MAF. Hope it helps.

http://nicoclub.com/zerothread?id=83404

 

his car is in the body shop . He said they got them to work with just the R4 . SO we will see

 

Yep this is a common practive, also part of the reason why APS replaced the OEM plastic MAF body and placed the sensor directly in the intake tube. I haven't held it in my hand but the APS tube does appear to have a larger cross-section? However; most (street FI) tuners tend to use a piggy back which drops into a MAP mode once the MAF has been saturated.( and clipped to 5V). With a oroperly enlarged MAF it would also be possible for the OEM ECU to be scaled to support larger (>500cc) injectors.

 

Frogot to add something. It is only pragmatic to play the MAF diameter increase game since the intake ductwork must be enlarged to accomodate the larger MAF diameter. If the step up and down become too great , un wanated turbulence can be created and minimize the sensor's linearity. Also just the act of expanding the range that the MAF sensor must span reduces the MAF accuracy. So a little enlargment is plausible, too much an be counter productive.

 

DWF350Z has put in the RC 550 injectors with the R4 program with no problems . Ive seen the maps and it looks like there was even more room for even a little larger injectors . John at Grubbs Infiniti is the one that tuned them . I wish he posted here . I may call him

 

I know this forum is a little old but hope someone still reads this. I'm about to go 550cc with te ss
box but I wonder if the online fuel pump (the one the kit comes from) will be enough? I'm not planing on putting more than 400whp since my block is stuck.

 

8 years, does he win an award?

 

I hadn't even met my wife yet when this was last posted in.


F*ck yeah this kid gets an award.

 

haha tell me about I already went trough a divorce, but made it thorough that's when I got married to my baby Z. .. haha

 

idk I just can't find any help with the vortech kit running bigger injectors and online fuel pump + tuning . I can go another way but don't wanna waist more money until I rebuild the engine.

 

I thought I gave you a bunch of Help !!!!!!

Well, I'll try and lay it out a little better.

1. When you say Online pump, you mean Inline.

2. You can Meet your goals by installing 440cc Injectors and a Walbro 255 Intank Pump, and Keep the Vortech fuel system with FMU, but change the calibrating washer in the FMU to a 6/1. Of corse you will need supporting Modifications like 3.12 Pulley, aftermarket Exhaust, ect. to make 400WHP.

3. If you install the 550cc Injectors and a Walbro 255, change the calibrating Washer to a 4/1. I think you will have Issues with tuning and will never get it Right, WITHOUT at least removing the Vortech Fuel System and adding a CJM Stage 0 Minimum.

I tried that setup but with 600cc Injectors and a DW300 In-tank Pump. I had tuning Issues with the transition in and out of Decell Fuel Cut-Off in very light Throttle, no matter what I did, it would not go away. So I installed a CJM Stage 2. All Problems Solved. Car is Tuned Perfect. No Issues at all.

I hope this Clears it up for you !!!!!

TimRod

 

yeah I had everything clear but there's not really good shops (tuners) around here and the one I'm gonna take it doesn't really know about the vortech system.

yeah I already have 3.12 pulley and full exhaust headers no cats+ intake pletnum

but my main question is would it work fine if I just leave the inline pump and upgrade the injectors? the inline pump as far as I know is a 155 + the stock fuel pump. just don't wanna invest that extra money for fuel system until I rebuild the engine.

sorry for the trouble. 😁

 

NO !

You need to at the Very Least upgrade your InTank Fuel Pump to the Walbro 255.

You will also need to recalibrate the FMU with a 4 to 1 washer for 550cc or a 6 to 1 for 440cc Injectors.

You will have a much easier time Tuning with the 440cc Injectors over the 550cc for this setup.

If you Upgrade the Complete Fuel System to a RFS type Tuning will be a piece of cake in comparison.

Making HP cost Money.....

1. Put the 3.33 pully back on, reinstall the tune for the 3.33 ( no cost)

2. Leave it just as is, but install a Walbro 255 intank. should be no need for retuning. cost of pump $75-$85.....

Question: what are the problems with your car? Why do you want to make changes?

 

theres no problems with it, I just wanna take it to get tune so I can get the most I can out of it and run it like that until my engine dies.

alright I'm gknna buy the Waldo 255, do how have to make some modifications to the pump or sawp it in.?

do you think you can give me the steps on how to recalibrate the FMU ? and by FMU you mean the one that comes with the vortech kit right (the blue one)

I would take it to a shop but like I said none of the shops around me know how to work on this kit and they don't wanna put hands on it. 😥

 

theres no problems with it, I just wanna take it to get tune so I can get the most I can out of it and run it like that until my engine dies.

alright I'm gknna buy the Waldo 255, do how have to make some modifications to the pump or sawp it in.?

do you think you can give me the steps on how to recalibrate the FMU ? and by FMU you mean the one that comes with the vortech kit right (the blue one)

I would take it to a shop but like I said none of the shops around me know how to work on this kit and they don't wanna put hands on it. 😥

 

Go to the CJM Website, they have step by step instructions on pump installation.

As far as the FMU, it only needs it if you change injectors.

You are fine with the Stock Injectors with the 3.12 pulley, if you install a Walbro 255 and leave the FMU Stock at 8 to 1.

Yes, the Vortech FMU (Blue)

You Can Not get the most out of the Vortech, without Spending $ Thousands of Dollars....

You Can't have Both, Spend No Money or Little Money, and Get the Most out of the Vortech. It's One or the Other.

 

thanks for the help.. damn I wish I could live in Florida I'll take my car to you so you can do all the work. so how much whp you think I can push with that setup (3.12+stock injectors+fuel pump+ full exhaust+ intake manifold)