Currently I have 370 injectors working with my emanage and they are running pretty good. However for my horsepower goals I believe I will need to use 555. injectors. I know sx7r has them on his car but he has not to ld wheter or not he has a rough Idle, or any of that other stuff. How hard it is to start the car . What fuel pressure the car is running at. Does anyone have the answers to these questions. I believe the nismo 555's are direct fit. but where can i get those or others. How much do they run? I am probably going to get them in the next week or so.

 

courtesy nisan would be my guess..

dyno tuning with the e manage for driving.. start up.. I have no idea.. but a GUESS would be 25 psi.

Maybe matt or icy can help there

 

The 555cc injectors are fine with the eManage, no idle issues. Remember the emanage can do upto 150% more than stock.

Dixit

 

So 555cc is pretty much the limit?

 

Pretty much until someone comes out with a different ecu program to handle higher than that. But 555cc is definetely good to at least 500whp.

Dixit

 

would that be applicable to a S/Cer set up with future potential future boost or more towards the turbo set up?

 

It applies to s/c or turbo. Boost is Boost. The more air you push into the engine, the more fuel you need. Simply put.

Nitrous is a bit different since a wet kit adds fuel with the nitrous.

Dry kit would need larger injectors (if you go big enough shot)

Dixit

 

dayum!!!! 846 dollas!!!!!is that for 1 injector?!?!? hey redmax!! can I get the set up from u if u choose to get the nismo ones?

 

Thats for a set of 6 not 1.

Dixit

 

didn't know anyone was wondering. it's idles fine. it cranks and starts up just like on stock injectors; however, for a split second after the engine cold starts, the rpm drops to around 500 and then goes right back up to the normal 1500rpm idle during warmup. this is just because the injectors are dumping too much fuel into the cylinders while the car is cranking. once the car is actually running, the emanage takes over and it idles fine. current fuel pressure is about 32psi at idle. i've tried from 30psi all the way to 38psi at idle and the results looks the same to me according to the wideband. apparently the ecu corrects to the ideal a/f ratio at idle. i have yet to really tune my car, so naturally, i have yet to see the full potential of these injectors.

 

Mardi mentioned the same initial flooding/stumble w/515cc injectors and JWT ECU. He said that when you turn the key to the on position and crank, the ECU dumps a bunch of fuel, so he setup a "START" button like on the S2000 to prevent that. Just FYI, but doesn't sound like too much of a concern.

 

putting the nismo injectors in, is there any other altercations besides the ECU? And Is it really a direct fit? Is'nt it a little bit bigger.

 

they are a direct fit as they are physically the same size as stock. i'm not too worried about the initial flooding as it doesn't affect daily driving. it'll do for now.

 

Sorry to hijack thread, but I have some questions abotu your 370 cc injectors... I dont know how much my current setup will make, but im guesstimating around 350 to the wheels with a 2.87" pulley. With some calculations , using a BSFC level of .6 and Duty Cycle of 80%. I would need 50 lb incjectors, or I would have to run the 370ccs at 87 PSI!! Is hat true, or are real world results different? Let me know... I am not sure what I need now to run my setup.. thanks

 

anyone?

 

im pretty sure 370cc injectors are maxed out at 350whp or very close to it this being at stock 43psi but you wont need to run them up to 87psi maybe like mid 50's

 

Do you have any idea what I will be running with my mods listed? i am actually hesistant about running the 2.87 pulley, because if that brings me over 350 whp, then I will defiantely be stressing the injectors... possibly the internals, plus when is a good time to upgrade the MAF, or the TB? When would i need to do that? what do you guys think? TIA

 

anyone have an idea? Maybe i should make a new thread?

 

I don't know what mods you have, but 350 at the wheels sounds a bit optimistic to me. Nevertheless, if you are using that number for sizing injectors, it's better to overestimate rather than underestimate the engine power.

 

Ok, heres a listing of the parts I plan to use...

Walbro 255lph Fuel Pump
MEVI
Vortech V1 Supercharger
2.75" Supercharger Pulley
XS Intercooler with HKS Skyline Endtanks 25"x13"x3"
2.75 inch piping
3.5 inch cold air intake with filter
Blitz Blowoff Valve
ASP Stainless steel pully tensioner and idler pulley
Gatorback pulley belt
Vortech FUel Management Unit with recal kit
AEM Adjustable Fuel Pressure regulator
6AN fuel lines
Apexi Super Air Flow Controller
370cc 300zxTT fuel injectors

right now, Stillen full exhuast, might change to WSP 3" full exhaust.

So with those mods, I'm look at around 11-12 psi of boost after the intercooler, and into the intake. Hopefully the air will be much denser after the IC. I believe that should net 350 with some tuning, if not, thats ok. Do you think I will need a bigger TB or a MAF that can handle more flow to attain those numbers? Or do you think that the stock internals can handle that much boost/power? Or anything else I should worry about? Thanks

 

IF you plan to support 350whp with a *SAFE* 80% duty cycle and 0.60 BSFC, you'd need approximately 530cc/min injectors.

In order to get 370cc injectors to flow like 530s, you'd need *ROUGLY* 90psi of fuel pressure.

 

ok... so that answers my question about fuel injectors...(90 psi is HIGH) Which is, get bigger injectors if I try to aim for 350 WHP. But then if I get bigger injectors, ive heard stories of having to get a new chip, because the current chip doesnt have the correct tables for the amount of fuel the 550ccs are providing? And also, will i have to upgrade the fuel pump to something bigger? How about the fuel rails? Will they support the flow if i need a new fuel pump? Also, idling will be a prob if I dont have a chip right? Because of the insane amount of fuel dumping into it... so I will have to get something that can control the Duty cycle of the Injectors to prevent the engine from flooding? (Emanage? ugh)

And for 350 whp, is there a need for a new MAF or TB? What do you think my setup would make, and what do you think that I would need in order to make it as reliable as a daily driver as possible a lot of questions I know... but thats why I love this place and you guys of the org

 

Again, that's pretty conservative at 80%. Guys are running more then that reliably, but it's NOT really recommended. Depends on if the risk is worth it or not to *YOU*.

If you get 550cc, you'll need an ECU from JWT or an eManage piggyback ECU.

Yes, Walbro GS342(255lph HP) seems to be the recommended best one. Fuel rail is not available and I don't know what its capacity is.

Yes.

I'll let StephenMax answer the MAF one.

For the reliability off the top of my head, read these for starters:
http://forums.maxima.org/showthread.php?t=285053
http://forums.maxima.org/showthread.php?t=284194

 

The best setup if you are going to use injectors larger than 370 cc/min, is (in my opinion) a JWT ecu programmed for the larger injectors and at 43 psi fuel pressure, and a Z32 maf. The JWT ecu will give you excellent driveability in all modes of operation (although I think mine is set a little lean at WOT, and I'm correcting with SAFC). The only difficulty may be with starting, based on what Mardi is saying. The Z32 maf is needed because the stock A32 maf is only good for an airflow equivalent to about 350 hp at the engine.

 

aha... I see... This is getting very tricky...I wanted just to go with the 370cc's and get 350 to the wheels with the mods I have now, but that doesnt seem very reliable now. Not with the high pressure to the injectors to get that HP, and not with the restriction of the MAF.... So when the MAF gets saturated by the excess air, will it report less than what is really being put in, and then the fuel injectors will put in the amount the MAF reads? In that case, it would run LEAN huh? So could we just use our airflow controllers to richen it up at the higher RPMs?

** also, another problem is that theres no ECU that I can get modified because of the year of my Maxima. (1997)... I know I CAN use the 96's, but then I would get that ugly CEL light all the time, and I don't feel like checking whether its a bogus light ot a real one all the time..

Also, what do you think I would realisitically get with my setup? Is 350 even possible with the 2.87" pully and the intercooler? If it is, then i have to worry, and if it isnt, then I SHOULD be ok with my setup, correct?

and what do you think it would be like wit hthe 3.125 pulley? Thanks a lot guys, you've been very helpful

 

You only need to worry about maf capacity if you are going with an air flow referenced setup like with a JWT programmed ecu. If you are staying boost referenced, like most of the people here, you don't have to worry about the maf limitation since you are providing fuel based on boost pressure. Several people here are making way more than 350 crank hp and maxing out their maf, but it doesn't matter since their fmu takes over when boosting.

 

If your maf is saturated, then injector duty cycle is also maxed out, and you can't adjust the afr downward with the SAFC. You can only adjust with fuel pressure via the fmu.

 

I remember reading a thread where IANSW was making 321 WHP or so, and he was running lean up top? And some of you guys suggested that maybe it was because of the MAF issue. But if it is indeed the MAF, and he is boost referenced (He is using the FMU right?), then the FMU should have richened while he was up top right? But it didnt... or does that mean he needs a larger ratio disk?

Also... when the MAF is saturated, does that tell the injectors to go at 100% duty cycle? Actually, that COULD be bad rght? Hypothetically, you can have BIG injectors, and from the way you explained, if the MAF is saturated at 350 hp, and you have 100% duty cycle, your injectors could be supplying a lot more fuel than needed(big injectors).
I havent read into the SAFC literature, but doesnt that trick the computer into thinking theres more/less air going into the intake, therefore it richens/leans the mixture up? Or does that not work when the MAF is maxxed out?

 

Ian has the JWT ecu, so he is air flow referenced and not using an fmu.

It depends on how much fuel is needed vs how much is being delivered.


Yes, the SAFC tricks the ecu, causing it to change the injector pulse width (duty cycle). But if the ecu is already working the injectors at 100% DC, then using the SAFC to increase injector duty cycle won't work. Pretty much whipping a dead horse by then.

 

If your MAF is saturated, then the ECU will work the injectors at 100% duty cycle? What if you have big injectors? and by running 100% DC, you overRICHEN the mixture... could that be a possible consequence?


Wait... The pulse width and the duty cycle are different entities... Does the AFC alter the pulse width, or does it change the duty cycle. It proabbly does the duty cycle, right? because the pulse width is just the time in each cycle that the injector can fire at... so if the PW is 5 ms, then 50% duty cycle will be around 2ms (with 1 ms of it being the injector opening)...

So thats good that I won't be MAF limited, but then again, my tuning will not be as accurate as the JWT ecu, being that I can only tune with my SAFC (500 rpm increments)

So with my current setup, what do you think the HP levels will be at? TIA

 

Cold start is a problem ony when its very cold, under 50f. Once the car is warmed up it will start up just fine, its only a problem in the mornings and in the evenings. The 3.5L TB also does not have the cold start fast idle cam like the 3.0L TB does, so I have to fight that.

I'll elaborate later, but... Its sure nice to have boost again!

 

Throttlebody? TB?

 

Yes TB = Throttle Body

 

I, along with most of the org, wait for your post

 

I want pictures and lots of info on the 3.5 swap, and will you break your current 1/4 record. I thought the 3.5 throttlebody was drive by wire or something like that, or is that only on automatic transmissions.

 

He's using a Pathfinder TB...still cable IIRC.

 

Yes, it could. The way Nissan seems to do things is to provide injectors that are the limiting factor, that is, the injectors will run out of fuel delivering capacity before the maf reaches its saturation point. So if you go with larger injectors, it is possible to hit the maf limit first. Whether or not that results in an overrich mixture depends on how much air is being pumped into the engine. It could be overrich, or just right, or still not enough. But with 555 cc/min injectors you will most likely be overrich at 100% DC, so you will need to lean out with the AFC.

You're right, pulse width and duty cycle are different entities, but they are very intimately related. Duty cycle is just the time that an injector is on compared to the total time available. So as rpm increases, available time decreases and duty cycle will increase even if the pulse width stays the same. The AFC just alters the maf signal either up or down, and then sends it on to the ecu. The ecu adjusts injector pulse width based on what it thinks the maf is measuring. But the AFC can not send more than a 5V signal to the ecu, no matter what, since that is the maximum voltage that the ecu can accept. If the maf is saturated at high rpm when the injector pulse width is already at 100% DC, then the AFC can not be used to increase pulse width. But with big injectors this won't be your problem. Rather, you will probably need to lean out the entire rpm range with the AFC. But again, it also depends on how much charge air the engine is getting.

With a 3" exhaust you will be somewhere between 320 and 350, I would guess.

 

Again, thanks for the informative post... Where would this org be without people like you

Ahhh... ok, That sounds good then. So even if the MAF maxes out and the DC is at 100%, I can always reduce the signal with the AFC if its too much, OR if its too little I can use a bigger FMU disk. but then I would have to lean out all the other RPM ranges with the AFC so its not rich down low right? You have the 370cc's correct? What pressures do you see when you are at WOT, and what kind of Hp levels are you making? Im curious as to what is better for the Fuel injectors.... Less DC % or less pressure? Because I can either run really high pressure to make the DC go to < 80%, or run lower pressure and have the DC% be near 100% at WOT.


Right on Forced induction 101

So with those estimates, I shouldnt have too much of a problem the current setup that I have? The 370cc's should be able to handle power level fine? How about if I stay with the stillen exhaust now? What do you think that will do? A little more torque in low/midrange, and suffer uptop? or would it be lower altogether. I know that you want the highest velocity exhaust as possible, and am not sure if this power level warrants an exhaust that size...

TIA

 

Yes.

I have a JWT programmed ecu, so my fuel pressure stays at oem levels. I'm creeping up on 300 fwhp (need to open up my exhaust a bit). In your case, I don't think fuel pressure is going to be high enough to worry about.


The 370s can handle up to about 350 crank hp at oem fuel pressure with .6 BSFC and 100% DC. I'm knocking on that door right now, so it's time already to think about providing more fuel. I just last year bought the 370s and had the ecu programmed (wish I would have gone with larger injectors to begin with), so I will probably go the cheap, er, cost-effective route and fool around with fmu's. Probably a Cartech unit, since they are so tunable.

The Stillen b-pipe is only 2 and 3/16ths inner diameter. I know because I have one and I measure it. It's really not big enough for boosted cars. People here seem to recommend 3" exhausts, but everything I've read about exhaust sizing says that 3" is overkill for the kind of hp levels (300-450 at the crank) most of us are making. If it is too big to fully utilize, then the trade off in torque reduction is not worth it, in my opinion. So I'm thinking 2.5" to 2.75" should be just right.

 

It isn't nearly as cheap as the Cartech or Vortech FMU you already have, but you might look into a MSD fuel pump booster, http://fuel.atrperformance.com/produ...?products_id=4.

Basically, it just ramps up voltage to your Walbro as boost increases. I've seen the flow differences Walbro 255lph HP pumps makes and it will definitely give you more room.

Just seems cleaner then a FMU, but probably too pricey for most to mess with.