how safe or not safe is this?

[trybal]

I just installed some 550cc injectors on my sr. I have stock t25, 3inch from turbo back, boost controller and thats about it for the motor as of now. I just got the injectors for a really good deal so i installed them. The car seems to idle solid, just high, at about 2k.

Would it be stupid to drive running that fat or no? I also have a safcII i just haven't installed it yet

[HyperTek]

should be ok.. install the safc if you can to prolly decrease teh fuel ratio?? i dont know

[trybal]

i just don't wanna overfuel the slut and mess something up, and the nearest dyno tune is about a 45 min drive...

[gear]

im pretty sure you'll be fine, i just wouldnt drive it hard until its tuned. Excess fuel makes the car run like shit, fouls the plugs, makes the oil foul quicker, and ruins catalytic convertors. (not necissarily all those at the same time, but it can be any combo) Id get it fixed relatively soon if possible.

[trybal]

yeah, i hooked up the safcII today, guess its time to decrease the fuel by 30%.. and i have no cat so that rules that out :-D

[trybal]

so i hooked up the safc but the car won't start with it hooked up, and i don't wanna mess with tuning it till i can afford to have someone else do it. So i disconnected the mafs from it. So running with the 550's shouldn't cause hydro lock or anything? The oil does look alittle thin right now and the oil smells abit gasy in the valve train

[DJ_Sunrise]

its gonna foul things up. have u ever done a compression test where the fuel injectors are still connected? if u have, congratulations! its how you blow your piston rings :D. imagine the same effect. all that gas is getting into oil. if u so much as have the motor running besides going for a tune, make sure it has fresh oil. keep trying to lower that fuel if u get the safc to work.. i would honestly try to get the car towed for someone to tune.

[shayrgob240]

I think you're just gonna waste gas. lol. But do get it taken care of asap

[johngriff]

Yeah, Um, YOU DONT NEED 550CC INJECTORS FOR A STOCK TURBO. What is the point? Since the 370cc injectors can handle the stock turbo @ 14psi, there is no reason to change injectors until you upgrade the turbocharger.

So, shelf the 550cc's until you uprgrade the turbo.

Oh yes. With the MAF unplugged, the ecu will send MORE injector open time, than with the maf connected, so you are once again hurting the engine more.

If the car does not start, after the AFC install, you have incorectly installed your SAFC. I would also suggest, selling it, burning it, or trashing it, because it is the WORST Air Fuel Computer Solution with vehicles with a DIS Load Based Ignition system.

[trybal]

yikes.. no love from you guys i see. Well i just picked up a z32 mafs and a fpr. Im keeping the injectors on here. I don't have stock ones anymore, 2 of them were shot. And how would hooking up the safcII wrong make the car not run? I know i hooked it up right. Thanks for attempting to make me feel like a douche though

[Wei240]

well, you see, people here are saying, unless you upgrade other stuff (like the turbo AND some type of good fuel management), it's kinda pointless... because the stock t25 maxes out around the same time the 370 injectors and maf, so if you upgrade your injectors, maf and not the turbo, what's the point... (besides potentially fvcking up everything else big time)

[trybal]

because i can. Whats the difference between my running 10lbs of boost with these mods, then someone with a 2871 runinng 8lbs on the same mods..? nothing... I upgraded because i had the chance to upgrade for cheaper than fixing with stock parts. So i did it, which im sure most of you would do also.

[S14DB]

Cause the 2871 flows a lot more air at 8psi then a T25 at 10.

[steve shadows]

should be ok.. install the safc if you can to prolly decrease teh fuel ratio?? i dont know


should be ok?:goyou:

Are you out of your fing mind?

Have fun soakingthe rod bearings.

It will ONLY* be ok if you install the afc and dial down fuel correction at least 35-38% across the board. I typically suggest people run 40 psi with vacum connected on sr and even then typically i need to pull an afc down to -40 or -42% all the way across the board.

NEVER install oversized injectors on any engine without a surefire way of properly controlling the open timeo or ecu.

Power FC or other more invasive management would be a much better bet to safley tune for this scenario even with the setup you have.

[steve shadows]

yikes.. no love from you guys i see. Well i just picked up a z32 mafs and a fpr. Im keeping the injectors on here. I don't have stock ones anymore, 2 of them were shot. And how would hooking up the safcII wrong make the car not run? I know i hooked it up right. Thanks for attempting to make me feel like a douche though

ok...

douche or not using an AFC is simply a bandaid.

It will allow you to do a ruff pulldown of injector via tricking the MAF sensor signal to the ecu, but it will not allow you to properly control and tune for appropriate timing and injector open time as a ems like a power fc or a aem etc would.

If you dont want the help so be it but John is right on most of what he said.

Use the afc to run the z maf, but IMO all you really needed to safely turn up the boost with an AJD fpr for your stock rail and fp gauge with the 370cc.

When you get the chance go pfc or haltech.

[trybal]

See, thats more of the helpful info i was looking towards getting. A gt series turbo is just a paycheck or 2 away, but in the meantime i would like to have a car to drive ya know. And lets say i do have a gt series turbo. And i drive around town all day without hitting boost, with the mods i have. Why would that be different than running what i have with the t25. It sounds strange to me that you need a bigger turbo to run this.

[NemeGuero]

You don't need a bigger turbo.. its just pointless to have 550s with out it.
370s are more than enough for your *current* application.

[trybal]

Thank you^^ kinda the answer ive been looking for. I did the injectors because i got a deal and i plan to upgrade my turbo very very soon, so why not get the supporting mods outta the way ya know. I don't consider myself anywhere near a expert in cars or turbos for that fact, but i know my way around a car. Im just looking for some advice on what to do to be able to run with these injectors. not how stupid i am for putting them on there. I know they are to big for my current setup, im not that stupid.

[johngriff]

Well..

The way the ecu determines fuel is pretty simple. It uses a table, that could resemble a MS Excel Spread sheet. Across one side runs RPM values, say from 0-8000. Across the Bottom runs load values, say from -30psi(vac) to maybe 14 or so.... err (map sensor will type settup will be used for example). There are typically 20x20 cells on the spread sheet, with each cell representing an injector open time. When two values intersect (rpm vs load), the ecu referances the corresponding injector open time as the signal to send to the injectors, measured by legnth. Typically with side feed injectors, you useable injector open time will be between 1.5-45ms.

At say 2000 RPM w/ -10(vac) at non WOT TPS the injector open time for a 370 is probably 8-10ms (milliseconds). If you plug in the 550cc injector, at the same rpm vs load point it will dial the same injector open time for that point, 8-10ms. You have now just injected about 35%-40% More fuel into the engine, making it VERY rich.

The solution to controlling the larger injector will be to "re-referance" the injector open time for this point. The SAFC accompolishes this goal by interfering the MAF/MAP signal. You use the afc to make the MAF signals referance to -20(vac) equal to -40(vac).

Doing this will force the ecu to reference a different cell on our fueling table. In which case this cell might contain 5.5-6ms injector open time, this will bring our AF/R on to target.

BUT! Using a dis ECCS car there is a very large catch. Because the ECU also completely controls the ignition system, it to is referenced the same as the Fuel Table. Actually the two stack onto each other the same. The ecu uses the same data LoadvsRPM to reference each ignition cell as well. SO, if you NEED to use the cell for -40 when you are actually at -20 you will also be using the cell for -40 ign timing.

This is where everything gets VERY f'd up. Your ignition advance and retard curves will now be permanently 35-40% behind where they should be. So when the ignition should be advancing for light load boost to help the Motor accelerate, it will still be using a vacum timing (32adv for mid range vs 15adv for vac/idle). This will have drastic effects on your fuel economy.

But wait, there is more. After the ECU Starts to reach full load, it will trim advance (retard timing) to keep the engine safe from detonation. Keeping in the therory that we are 35%-40% behind our loaded ignintion curve, where the timing should be 20-25adv you will be at 30-35adv. Too much advance timing promotes Knock, Ring failure, over heating, and head gasket failure.


All in all, you have hurt yourself much more, by upgrading the injectors, then proceeding to you use a dangerous fuel contoller. If serious engine damage does occur you could be out as much as a comparable EMS system when taking into account the cost of injector upgrade + SAFCII+Engine rebiuld or new JDM engine.

In short. IF this is your Daily Driver, Replace the 550cc's with 370cc's and cruise it stock. Peice the parts together for a good setup on the shelf, then install all at once. Purchasing the correct components the first time will always save you time money, and hapiness in the long run. Also, do not be afraid of systems like the PFC (i recomend against), or the Haltech. These systems have become very easy for the beginner to tune, with base maps loaded, and a efi book or two, you will have your car streetable in a matter of hours. There are also more AWESOME resources for you to read up on, to make an informed desicion on EMS systems. www.efi101.com is a great place to start!

Have a great day.

If you need any other help, dont be afraid to shoot an email at me as well.

John

[email protected]

[trybal]

Thank you so much^^^^ props to that write up for me. I never looked at things that way till now. Well i guess i will go out and buy another set of stock injectors. On the other hand, do you recommend slapping the z32 mafs on there with the stock injectors?

[johngriff]

If you decide on the Power FC I would keep the Z32 AFM, but the pleasures of using a MAP sensor over a MAF are comparable to illicit street drugs. I would hunt for a Power FC DJetro, or the Haltech, which both use a 3 bar map sensor. Yet, a little known fact about the PFC is that you will need a Certified Excel Tuner to make significant modification to your PFC. You can locate one on Apexi's website. The labor rate (ie dyno time + power excel tunner) is from $250-$400 per hour. The only other current solution is the Data Loggit out of NZ/Austrailia which is a third party component that will void your Apexi PFC warranty.

For the Stock T25@14psi the Z32 Air Flow Meter will be moot. The OEM SR or KA maf will suffice in this instance. Plus you get to run open turbo, or just turbo w/an air filter with the MAP, which always looks tits.

There is also a couple other things to say about EMS systems.. the EXTRAS, anti lag, all in one boost control, nitrous control, fan control, DATA LOGGING (LIFE SAVER!!) plus alot more.. there are alot of really cool things that would take 2 s13 dashboards of small boxes to make up for with just one good Haltech.

Give me a call i have some "unreleased" equipment for the haltech you might be interested in.

John
714 493 0293

[johngriff]

I am bumping this, because people NEED to READ this.

Don't get an AFC / AFM manipulator.

[nicku]

My setup is redtop, s15 t28, nismo 555cc, stock maf, boost controller at 12psi, safc, plx wideband. Right now my safc is set at -30 across the board. And the car is running fine. Do you think I can boost up a little more? When will the stock maf max out at this kind of setup?

[DarkPhoenix]

Don't get an AFC / AFM manipulator.

Besides not having enough resolution, why would running an SAFC be a bad thing? Sorry, I have been running turbo cars for ten years, and everyone of of them either had the old school AFC (5 knob) or an SAFC2, with great results. My last car was a 1992 Galant VR4, with an HKS VPC and an SAFC2, and I will able to tune it for 400+ whp on 720cc injectors, and still get 30 mpg on the highway. This was a street tune, with a wideband and EGT.

Haltech would be great and all, but when you can tune a street car with a fuel controller and it would be cheaper (Around $200 for the AFC and the Haltech is about $1100+ for the E6X), why not go that way? I'm not trying to bust balls here, but I am curious.

[SlideWell]

^^^^ +1 on that. shiet, Keisuke didn't say anyhing bad about my friends s14 when he was tuning it out to over 400hp. ive only heard great things about using an AFC. if you could explain why thatd be great.

[johngriff]

The reason why is because the nissan ECCS system changes the ignition timing based on the AFM load input into the ecu. You need to have control over the ignition timing to prevent knock. Without knowing the base settings of the ignition you are flying blind when doing an SAFC tune.

The emanage is a good low cost solution to this, so is the Perfect Power.

http://www.perfectpower.com/

Basic Air flow meter manipulators are junky at best. And DSM's are known for responding VERY well to AFC's, this is probably because of the linear design of their ignition maps, compared to the non linear loaded/unloaded points in most nissan maps.

[DarkPhoenix]

The reason why is because the nissan ECCS system changes the ignition timing based on the AFM load input into the ecu. You need to have control over the ignition timing to prevent knock. Without knowing the base settings of the ignition you are flying blind when doing an SAFC tune.

The emanage is a good low cost solution to this, so is the Perfect Power.

http://www.perfectpower.com/

Basic Air flow meter manipulators are junky at best. And DSM's are known for responding VERY well to AFC's, this is probably because of the linear design of their ignition maps, compared to the non linear loaded/unloaded points in most nissan maps.



But DSMs have the same issue with ignition control that the Nissan's have. On a 2G it's worse due to the OBD2 configuration, making any timing changes impossible without either a NEO, or another separate timing controller. I was just curious because of my success with them, in my DSMs and my Z31s and Turbo S301s.

[nicku]

so John, you are saying that if I keep using safc, enventually , i will blow my engine?

[johngriff]

AFC NEO? I did not know they can control timing, and am 99.999% sure they can't. My experience with the neo was that of a dressed up fat girl. I would rather just have the plain old fat girl with the safc-II than the neo, it was much easier to tune.

I am NOT a DSM expert, so don't quote me, in my experience, what I've seen, I have seen allot of DSM's go fast with AFC's.

Will you eventually blow your engine? Who am I to judge, it is really dependent on so many variables, I can't start. If you are knocking, then yes, you will blow your engine. That can be from timing, lean af/r's or and ESPECIALLY HEAT.

I just like to know WHAT my ignition values are, and to view the tractive effort output (tq) of the engine, ensuring it is making the most power before the detonation thresh-hold.

nicku: what is the end result of your concerns? Take the car to a dyna-pack or a dynodynamics, get the tune checked out, have the technician check it out with with an advanced knock detector, you will have your answer from there.

[tgd89]

What about something like nistune, as compaired to a haltec? Though I don't think you can use a MAP with it.

[smelly240]

so you know - you can run a z32 maf with 550s and apparently it will run almost exactly like stock.... i didnt believe it until i seen it. afc sucks wee wee.

nistune is a type of daughterboard that added a few things including real time programmability and stuff. Its a lot of $ tho - u might as well get a E6K or something from johngriff

[drftmark]

so you know - you can run a z32 maf with 550s and apparently it will run almost exactly like stock.... i didnt believe it until i seen it. afc sucks wee wee.

nistune is a type of daughterboard that added a few things including real time programmability and stuff. Its a lot of $ tho - u might as well get a E6K or something from johngriff

http://www.zeroyon.com/pics/installs/inectorsMAF/550Z32-1.html

Thats what this guy is talking about ^

Anyway, listen to john, he knows his stuff. I bought a Haltech E8 from him and I am getting it tuned this monday. But trust me, hes awesome and will help with anything.

[jspaeth]

If you decide on the Power FC I would keep the Z32 AFM, but the pleasures of using a MAP sensor over a MAF are comparable to illicit street drugs.



hahahah fucking hysterical

[jspaeth]

What the fuck is with people....I am reading some people's responses in this thread and am dumbfounded.

John explained twice that using AFC to alter injection causes the ingition to get messed up.

God.

[OfourTHREEfive]

I never thought that the timing would adjust and cause knock with the SAFC2, good to know.

Have to save up and go emanage :(

Should I just bite the bullet and go EmanageUlti john?

[DarkPhoenix]

What the fuck is with people....I am reading some people's responses in this thread and am dumbfounded.

John explained twice that using AFC to alter injection causes the ignition to get messed up.

God.


The only way I see that even being possible is if the ECU doesn't alter the timing. The way it should work is if you adjust the injector pulse enough to cause it to lean out, the ECU should pull timing. The way it knows it should pull timing, is by use of the knock sensor, if so equipped. Most cars that are running a fuel injection, all have provisions to pull timing in a lean, or low octane condition. That is why most cars that "require" premium petrol, will run fine on regular, but it will pull timing to protect itself.

Now, all an AFC does is "trick" the ECU into seeing a different value from the MAF, basically causing the ECU to reduce the amount of time the injector stays open, to attempt to match the values that the O2 sensor reads, with the the MAF is showing it. Nissan ECU's aren't too different from the Mitsu ECUs.

Basically, what I am saying is using an AFC will not cause you to blow up your engine anymore than a Haltech, eManage, or AEM EMS would. It all matters in the tune. If you tune it properly with a wideband O2, there is no reason that someone using an AFC can't have a safe running car.

[g6civcx]

I agre mostly with johngriff. You can use an AFC as a band-aid, but the AFC doesn't have the adjustability of a standalone.

[nicku]

John, I am just wondering if im not looking for crazy horse power. My target is probably 280 or something like that. Is it okay to use just safc since I just want to slightly tune my car?

[hstylez]

Great information here. Thanks John :bigok:

[BoostinGST]

John, I am just wondering if im not looking for crazy horse power. My target is probably 280 or something like that. Is it okay to use just safc since I just want to slightly tune my car?
if you just want to slightly tune your car you would be better off getting an enthalpy tune, the safc is a good product, just not as good with our cars... yes it will work, however to make hp using it will be hard since you will be pulling timing when your adding more fuel if im correct. i think you would be better off with something else like an emanage, map-ecu, pfc, or the mail order tunes. just dont cheap out or you might end up getting to spend the money later on another motor. also get a wideband, you can safely tune your own car for the street.

[e1_griego]

It's not rocket science, jesus.

Using the tps and the maf, the ecu comes up with a TP (theoretical pulse) value based on input from the tps and the maf. Basically the ecu works as a lookup table, so there's a big map of TP vs rpm, for BOTH fuel and timing. When you manipulate the the maf signal, you change the TP, which in turn fucks with both the fuel and timing.

It's not ideal.

Alex

[johngriff]

It's not rocket science, jesus.

Using the tps and the maf, the ecu comes up with a TP (theoretical pulse) value based on input from the tps and the maf. Basically the ecu works as a lookup table, so there's a big map of TP vs rpm, for BOTH fuel and timing. When you manipulate the the maf signal, you change the TP, which in turn fucks with both the fuel and timing.

It's not ideal.

Alex

Right, which is the point I am getting at.

Nistune looks really really cool, I have played around with the software, and a couple other vendors, I like the idea of live tuning via usb using the daughterboard solution. I would like to see more mainstream support, and get my hands on one to tune live to really back it.

Yes, save your money for the Ultimate over the Blue.

The emanage is a piggy back "clamp" system. It "clamps" the standard injector grounds, and uses its OWN drivers to make new injector grounds which are user defined. When you make changes to the fuel, it does not effect the ignition table, because you are not manipulating the AFM signal to effect the VE (load) to effect the injection.

I LIKE the AFC for two functions. Air Flow Meter Conversion (like stock to N60) and the off throttle correction function. Where when using an open atmosphere bov you can correct the blow back and use it as a stall saver. Othere wise I don't like it for manipulating the AFM signal, I just don't think its correct.

Yes, Ideally the AFC would only change injector pulse, but It does not. The computer you are using must have its OWN ground drivers for the injectors to do this, whether it is a piggy back or user programable computer/replacement computer.

There are allot of different solutions engine managment, that scale from hundreads to multi thousands. Its about your budget and what goals you need it to accomplish. Its just that AFC's are NOT a replacement for engine management, hands down.

[e1_griego]

Its just that AFC's are NOT a replacement for engine management, hands down.

YUP :)

Yes, nistune looks rad and it's something I'd like to buy this year. I'm currently just using a stanza ecu, datascan (for the maptrace), a rom emulator and rom editor, and a wideband (yay single cam). Not as slick as nistune, but a helluva lot better than afc.

Alex

[adictd2b00st]

There are allot of different solutions engine managment, that scale from hundreads to multi thousands. Its about your budget and what goals you need it to accomplish. Its just that AFC's are NOT a replacement for engine management, hands down.

i don't think anyone ever really said it was....... while you on the other hand made it out to be like he was running an FMU for "management". yes an afc isn't the best option, but its not the worst either. i daily drove an s13 with z32 maf/550s/s15 t28 on an afc for almost 2 years with no problems at all. just keep it within its limits.....

and before someone tells me i don't know any better, i've owned multiple cars running an afc / haltech / power fc so i do have bit of a clue

oh and to the one who said he would be fine running those injectors WITHOUT the afc, thats just ridiculous :eek: i really hope noone is following that advice!

[johngriff]

Well its really more of this theory that AF/R is everything about tuning the car.

At best AF/R is a management of heat and not so much directly proportionate to the amount of power output by the engine. The ignition timing has much more to do with making power numbers only secondary to air flow. Don't take this out of context, its just a 11/1 to almost 13/1 AFR will produce the same amount of power as long as heat is kept in check (thus not detonating).

Simply tuning the fuel alone is not doing the upgraded turbo any justice.

[Matej]

How far can you get with just tuning the ECU? DOHC KA to be specific. My ECU already has some kind of an N/A tune, it came out of a track car owned by a guy who runs a tuning shop, so I'm curious, is tuning the stock ECU only good for an N/A application, or could it be possible to tune it for a basic T25 setup with 370cc injectors and eliminate the need for aftermarket management? Just curious, sorry if that's a really stupid question, I'm a noob when it comes to engine management.

[adictd2b00st]

Well its really more of this theory that AF/R is everything about tuning the car.

At best AF/R is a management of heat and not so much directly proportionate to the amount of power output by the engine. The ignition timing has much more to do with making power numbers only secondary to air flow. Don't take this out of context, its just a 11/1 to almost 13/1 AFR will produce the same amount of power as long as heat is kept in check (thus not detonating).

Simply tuning the fuel alone is not doing the upgraded turbo any justice.


this is true, i agree with you on that one. piggybacks can only do so much and there is definitly a point when it isn't really an option anymore

[johngriff]

It is possible to tune a factory ecu to handle that kind of setup or even bigger. The problem is having live control during the tuning process, and being able to modify the tune easily when conditions change.

That is why a daughterboard system like nistune is on the surface so promising, my only question is support, and a track record of reliability. That is why I want to get my hands on one.

[mifesto]

i may be picking up a s14 which has 550cc injector and z32 maf running roughly 1.2 bar on gt28.... it already includes the intec rom ecu. i think i may buy the safc2 just to do light adjustment under wideband... i dont think timing will very much long as my adjustments are small and afr is smooth and about 11.5 at top end....and ofcourse zero knock.

[johngriff]

mifesto: There really isn't much reason to use the safc2, if your ecu is allready chipped for your current setup. IF it isn't running correctly on the chip you have, exchange/upgrade the chip before buying and installing an safc.

[slow40sx]

if u have an adjustable fpr u should be straight

[johngriff]

Eh, tuning turbo cars off of fuel pressure regulators is no bueno my friend.

Adjustable's are good, to make sure you have a good baseline set, but you always want that fuel pressure as a constant part of your efi tuning formula.

[johngriff]

I am bumping this from the dead for people to read, because I see allot of chit chat about tuning with AFC's again...

[Choku_Dorian]

I am bumping this from the dead for people to read, because I see allot of chit chat about tuning with AFC's again...

thanks.

not that i am looking into tuning as of right now but some great info to read over for us who aren't tuning specialists.

[RPSport.net]

thanks.

not that i am looking into tuning as of right now but some great info to read over for us who aren't tuning specialists.

Exactly! There is allot of good info buried on zilvia. Sometimes some of it needs to be zombified, and trotted out for discussion.

[fullthrottle]

I am bumping this from the dead for people to read, because I see allot of chit chat about tuning with AFC's again...


I am bumping this from the dead because I just bought an afc neo and then decided to search about it. I will never EVER buy another part like this before searching. Honestly if I could only have access to one website for the rest of my life it would be zilvia.net/f/