600cc's and Idle

[Xero]

K, I know I asked this a while back, but I never got an answer, and others were as curious as me.

Larger injectors have a minimum fuel that can be injected when activated. That can 'cause alot of richness at idle, and richness at lower RPMs or lower boost levels.

For a 400+hp CA, I'd need Tomei 600's, now, I COULD, run NISMO 450s or Tomei 555s, and add a single injector somewhere, but that's BS that I don't wanna deal with.

So, what size injectors are you running, if they're 550+, and what kind of idle do you have, and what kind of boost do you run on the street? I'd really like to run 7psi on the street, 'cause I drive long distances right now, (that will change this summer, but still, why waste gas for no reason, I don't plan on racing it on the street, and the KA24 is fast enough for an aggressive jaunt from lights from time to time)

[rs13]

I used pwer enteprice 700cc injectors on standard fuel pressure with a home made 3" air flow meter and a Perfect power SMT6 piggy back ecu, and it extremly lean on idle, ehan I adjusted the calibration on the SMT it went perfect and idled as a factory engne, without doing any more adjustment I was able of running 1,5 bar on a turbonetics T3T4 turbo.I had a ported hesd, pulse split manifoild tomei 270 cams, greddy piston/rods and 1,6mm head gasket, cusco 5,1KG flywheel/clutch, fully balanced internals and a greddy R/spl intercooler, with 0,05-0,1bar boost pressure the engine power was 171HP and 225 at 0,3-0,35 bar at 1,5 I don`t know...

Christian

[float_6969]

??? ,=. ???

[Xero]

that still didn't really help me, I have a hard time believeing 700cc injectors were running LEAN at idle.

[float_6969]

I think that if you have a good enough control system, you could tune it way down at idle so that it would run alright. I don't think you could do it with a piggyback of anysort, but I don't have any hands on experience with injectors that big, so I'm not sure.

[Xero]

what I'm getting at is tha tyou can only get a signal so small, and that injector will have a minimum of fuel it injects. No matter how short that signal to it was, it still has a minimum.

With 700cc injectors, they have large "ports", if you will, so alowing that solenoid to open and close, it will inject so much fuel. With a large injector like the 700cc, it'd be hard to get down that low.

I just don't wanna run rich, or with a high or nasty idle, running 600cc's. I also don't want to have to run 14psi daily, or whatever.

[BoostFab]

XERO: what management are you using? note that, even large injectors has a certain small pulse range, with the right fuel management, you can idle. we recently tuned a sr motor with 72lb injectors running Haltech standalone and didn't have problem with idling that monster. it should be the same case for CA motors.

[BoostFab]

??? ,=. ???

some foreign countries punctuate their decimals using "," rather!

[quest]

lotsa 2.0s run good on 720s. 600cc should be fine as long as u have a programe for it or some sorta controller.U must have 400+whp in mind. 7psi on what turbo ?

rs13Your setup sounds interesting. Car should be fastCan you adjust fuel AND timing on your ca18det using the Perfect power SMT6 piggy back ecu ? Thats what I had plan to try out

[float_6969]

Boost Fed-Thanks, I didn't know that! I feel so much more worldly and well rounded now.Hehehe

[drumma022]

I am running 720cc injectors and can have my car idle as low as 5-600 rpm and this is with 270 duration cams. Anything lower than 5-600, the car starts shaking and the engine doesnt really like it too much. I run minimum 9 psi daily and often see 25 psi when I am feeling the need.

[Xero]

k, thanks guys,

Fuel management is planned to be done with an Electromotive TEC-3, so I shouldn't have a problem just making sure that the huge injectors could get down that low, I was under the impression that they couldn't.

I want 7-9psi daily, but 20psi when I need it. The engine when I build it will be capable of a bit more, but from my understanding (as you can tell, it's been kinda going down the tubes lately), the turbo won't be. HKS GT2835R.

[float_6969]

Not to say I told you so, but, I TOLD YOU SO!!!

[Xero]

man, you like making me feel like a n00b, dont you...I will get you back one day, oh yes, I will...

[rs13]

Hi It was runnng lean due to the home made 3" air flow meter, its basicly the standard sensor pt in a 3" pipe when the standard is 43mm and the home made 75mm its getting a lot more air and sensing the "standard" flow, this leading to a lean mixture.When I used the piggy back ecu to adjust the opening time of the injectors it ran perfectle all the way to 8000rpm,if you use a standard air flow meter and bigger then the 444cc injectors from a skyline you will have a over fueling problem all the rev range on the standard chip.

Christian

[rs13]

I think that if you have a good enough control system, you could tune it way down at idle so that it would run alright. I don't think you could do it with a piggyback of anysort, but I don't have any hands on experience with injectors that big, so I'm not sure.

With my piggy back I ran a perfect air fuel ratio with 700cc injectors on as low as 0,1bar boost, this is aprox 1,5psi boost pressue.It has a fuel zero calibration where yu can change the input all over the rev range at once and then tune on each rev setting, this is used to compansate for bigger injectors, different air flow meters and other thingx that make a differens in what innput/output signal you use.I run a Perfect power SMT6 piggy back on my CA

Christian

[quest]

rs13have you adjusted your TIMING also, using the SMT6 piggy back ?

[rs13]

Yes I have adjusted it, I can adjuste timing, fue,l have extra injectors, make fuel/timing changes for NOS any somemore things.

Christian

[quest]

cool,I wondered how the nissan ecu would behave when u altered the timing via the SMT6 piggyback. The fuel never seems to be a problem to dial in, but when u alter timing you're going after bigger power.Emanage has issues with timing on the CA, but I read they had a patch for it.I've seen a guy run the SMT6 on a supercharged toyota truck that also has coil-on-plug ignition, and PP worked with him until he got it to tune like he wanted. Pretty neat product

I take it that you like yours, rs13

[Xero]

There is a top ECU tuner in Japan, tunes JGTC and D1 cars for a living. He prefers to use the Nissan ECU because it is so versatile and responds well to tuning, it doesn't try to **** with the tune, like the new EVOs or the STi/WRX's do. If you tune one of these "rallye monsters" eventually, they convert themselves back to stock.

[nab911]

Im planning on getting an e-manage system but after reading this i found out there are more systems out there than just emanage and safc 2

[boost_boy]

Quote »but after reading this i found out there are more systems out there than just emanage and safc 2 [/quote] There are many more that are better than those two as well.

[Xero]

Power FCSDSHKS FCON V-Pro (If you had the power writer which NO ONE has, other wise I'd get that)