Safc 2 on stock sr

[shawn1331]

Hey guys i have searched and didn't really find a lot of info regarding a stock sr, most guys had bigger turbos etc.

I have a redtop, stock t25 stock maf stock injectors stock ecu, fmic hks ssqv and 3 inch exhaust, running about 10lbs right now. looking to make a bit more jam.

I've heard some guys say that all else stock an sr is good til 250whp then evrything basically maxes out.

Could i reach 220-240whp fairly safely with a dyno tuned safc 2 setup? I dont want to dump a ton of money into my sr bc im building up a new motor for next season so it's a daily this year, and 230 or so would be a ton. I have a wideband.


Please don't bother saying to get a proper map because if its not safe on a safc by a competent well respected local tuner than i won't ill just leave it stock as i said i dont see the point in spending 1000's for 4 months of fun.

[Croustibat]

You obviously already know the answer. Why even bother asking the question again ?

Unless you actually don't want an answer, but rather a justification to using an SAFC.

Sorry, but these things belong in a bin. And yes, get a competent tuner make the tune because you also obviously have no idea how an SAFC operates, nor what "makes more HPs" in a tune.

[MADE]

While not optimal you can probably hit your low target safely. I knew people who used SAFC sucessfully. I dont see it as being a good $ for the gain.

[shawn1331]

LOL fuck of crousibat. I never said any of that. I've never had first hand experience with one and wanted some input. I only hear of people using them with different mafs and injectors then original and trying to change their set up completely.

Take your high horse out of here because I don't need it. No reason to be a douche bag, I'm not new to 240's at all. I've never used a safc


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[shawn1331]

Thank you made. Appreciate the input


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[Croustibat]

I've never used a safc


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Then keep doing that :)

It is a piece of crap that alters the MAF signal, you can set your AFR somewhat properly at the expense of random ignition timing. Hence EVERYONE says it is crap and a hit on THE SEARCH BUTTON would have answered your question.

And again you KNEW the answer as you already stated it as the last sentence of your first post.

I don't care if you are new or not, if you act like a cunt, you get that kind of answer.

[OBEEWON]

SAFC is great on JZ engines, but not Nissan engines. Your SR will poop its drawls.

[silverarrow27]

SteveShadows use to use one on his s13 in his drag racing days. Hit him up to see if he'll give you some suggestions.

My recommendation is to order whichever EMS you were planning to go with originally for your built motor and use it for your current setup so when your new motor is done and installed, you already have the EMS in place and ready to get retuned. But that's just me though.

[Croustibat]

SAFC is great on JZ engines, but not Nissan engines. Your SR will poop its drawls.

No it is crap on both. The reason JZ engines tolerate it more is because the stock tune is ultra conservative in its timing and fuel settings.

[OBEEWON]

No it is crap on both. The reason JZ engines tolerate it more is because the stock tune is ultra conservative in its timing and fuel settings.

I don't like your attitude.

[Kingtal0n]

No it is crap on both. The reason JZ engines tolerate it more is because the stock tune is ultra conservative in its timing and fuel settings.

This is correct, but with respect to its MAP sensor

a 2jz-gte JDM engine can easily be tuned at 500rwhp with a safc2 (or other piggyback) for a daily driver and this is one fantastic daily.

Learn how these objects work.
An safc ONLY does something this:
maf input voltage -> maf voltage adjustment -> maf output voltage

It wires in like this:
Maf sensor -> safc -> ecu


Do some research, what voltage outputs do stock maf sensors coorelate?
ex. maximum voltage of the stock 2jz-gte MAP is 4.877 volts? (= 4,877mv)
it correlates with 437bhp on the stock engine with 0.1 miles, and average 397bhp on an engine with 150,000 miles, and about 17.15psi (fuel cut on 4,911mv)
Because a MAP does not measure moles of air, the constant in the fuel map will not longer fuel the engine if volumetric efficiency is increased. Where a maf sensor would notice the additional airflow, if it does not exceed max value. Why do these sensors have maximum values? Using an appropriate sized sensor gives better resolution than a larger sensor would. Never use a larger maf than necessary.

What is a maf? A wire that must maintain a temperature setting, rigidly mounted inside a tube of fixed volume? The amount of voltage required to keep that wire a specific temperature is what we are seeing. because the ECU has an equation setup that converts maf voltage to mass of atmosphere, literally how many moles of atmosphere/O2 are there available to react with, it could directly calculate a theoretical air fuel ratio using predetermined constants (like the fact that atmosphere is not 100% O2 and may vary, and the fact the volume of the maf tube does not change, and that the alternator will be supplying 13.2->14.5~volts) changing anything related to these calculation constants such as injectors maf or ecu, even just changing the voltages they are working at will have an effect on the mass of fuel ultimately injected based on the maf signal. Tweaking it directly with a dial sounds like a great idea...

... however there is, sadly, another map will go along for the ride, the timing before top dead center map. If the ecu suddenly seeing less moles of air entering the engine per unit time, it will calculate that the cylinders are suddenly less full, it will think volumetric efficiency has dropped because you turn the dial counter clockwise. This normally means it would be safe to throw a few more degrees of timing in there... when in reality, you just dialed your maf voltage back with your hand, and the cylinders are actually MORE full than they would ever normally even be, this is where you want to be removing the timing, so not only do you not remove timing, you are making things worse by adding it.

Not a whole lot of room on the sr20det for timing to wander
http://i23.photobucket.com/albums/b378/draglarry/P1220403.jpg

[jedi03]

Plus one on don't spend money twice...get the ems and call it a day!

[Croustibat]

I don't like your attitude.

I usually do not sugar coat things.
That is the truth, and it only took you a line to read instead of a wall of text.

By all means, check for yourself.

[OBEEWON]

You are right-ish.
But like the fellow said above it works at no danger to the JZ engine. It's not optimal but hey. I've had it on the SR and RB and its terrible. But on JZ stuff I've seen mid 5's with solid AFR's and EGT's etc.

[5280VertDET]

Here is a better option:

http://www.j-k-tuning.com/ecuservices.php

OBD1 Nissan Installation of 2-chip daughterboard + Basemap chip $125

[Croustibat]

+170$ harness conversion
+400$ for the software

meh.

Honestly, for his level of modding a simple mail order chip would be enough.

[Jimmy Up]

I made 239hp, and 240tq on a dyno, stock t25 SR with an SAFC 2. I popped 2 motors in 3 events. I just put everything back to stock, and had the best weekend of drifting I've had in years. The car felt great and I won't be making any extra power until I go stand alone.

[shawn1331]

Well my next motor isn't another sr hence the reason I don't want to pay $400-800 for a tune.

I'm just going to leave it as it is at the stock 11psi an have fun until it either dies or the snow falls again. Didn't mean to start an argument.


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