Upgraded MAF with Upgraded Injectors, NO Tune! Possible?

[dg_performance]

Im a little new to the nissan world but i figured i would see what you guys think about this idea of trying to avoid ecu tuning with power upgrades.

A rb25det Maf reads 0-5.12V.... and that is based from 0-4423 Flow UnitsUsing the stock 370cc injectors the computer needs no tune since it is all stock!

A z32 Maf reads same 0-5.12V ... but at a differnt flow rate of 0-7546 Units Since the rate of difference between them is .587

In theory "586cc injectors" ( i know they dont make that exact injector size) with a z32 maf could run perfectly on stock rb25det ecu? Right?

The ecu would be basically doing the same math without knowing the upgrades are installed.

If the factory ecu should run the injectors at the same rate of air it sees from the MAF. I think it would be compensating for the upgrades without knowing!

Has anyone done something similar to this?

[eh?]

Quick and easy way to blow an engine.You left out the other side of the equation.

[WhatsADSM]

Yea that is asking for trouble on the ignition timing.

Truthfully trying to "avoid ecu tuning with power upgrades" in general is a bad idea.

[Sil240]

Don't do it. Spend the money and do it right

[Cjmartz2k]

That's only good enough to get the thing to idle and drive to the tuner. There is a lot more to it than just matching the injectors to the MAF.

[dg_performance]

Here is my situation...being my first nissan, i dont want to kill it.... point me in the right direction please on what i need or where to go to get what i need. tuning is my weakpoint. i have only safc tuning under my belt with a wideband logger.the story:i just broke in the clutch and wanted to finally romp on the rb a little figuring it would hold 13 psi on stock injectors, ecu, maf ....and it runs like a** when i jump on it. the thing runs perfectly fine driving normal breaking the clutch in.

Rb25 series 2i upgraded the oil pump, water pump, thermostat, belts, plugs, ect....all that!isis intake maniq45 tbwalbro 255lphcustom t4 manifold gt35 turbo .68 hot side3" ic piping50mm dump3" exhaustspec stage 3

[gawdzilla]

first thing... stop romping on it

you already spent good money on parts, so don't blow them up and trash your investment. the gt35 is much bigger than a stock rb25 turbo. you can easily max out the maf/injectors with it.

here is what i would do in no particular order. imo all these are very important.

1) what injectors are you running? you probably need at least 600-700cc's if you want to see the full potential of that turbo. otherwise, the stock 370s will only give you ~300 whp safely with normal fuel pressure.

2) get a tunable ecu. a lot of people like nistune these days, which is also budget friendly.

3) get a z32 maf to support the additional airflow. you can use the stock rb25 maf to about ~400ish whp before it maxes out.

4) wideband and tune. if you're not comfortable DIY, find a capable tuner.

[dg_performance]

im using the stock injectors and maf and ecu since i was breaking in the clutch while i saved up more $ to get fueling/tuning other parts.

i have a z32 maf not installedi have a aeromotive FPR will be putting in as soon as my fuel rail fitting comes in.

i did not want to install the above to mess with factory ecu tune.

i have a wideband i will be putting in asap now!

[Cjmartz2k]

K, bottom line, you need to get an ECU like a Power FC, Nistune, AEM, etc. Then you need to put it in, install the Z32 MAF (which will still probably come up short considering the size of your turbo) and get it tuned by a pro. Tweaking out fuel with a SAFC is one thing, but tuning a 600hp capable turbo'd car is WAY different.

[Darius]

Im a little new to the nissan world but i figured i would see what you guys think about this idea of trying to avoid ecu tuning with power upgrades.

A rb25det Maf reads 0-5.12V.... and that is based from 0-4423 Flow UnitsUsing the stock 370cc injectors the computer needs no tune since it is all stock!

A z32 Maf reads same 0-5.12V ... but at a differnt flow rate of 0-7546 Units Since the rate of difference between them is .587

In theory "586cc injectors" ( i know they dont make that exact injector size) with a z32 maf could run perfectly on stock rb25det ecu? Right?

The ecu would be basically doing the same math without knowing the upgrades are installed.

If the factory ecu should run the injectors at the same rate of air it sees from the MAF. I think it would be compensating for the upgrades without knowing!

Has anyone done something similar to this?

Mustang guys do this all the time, so there has been quite a bit of trial-and-error done to ensure that certain injectors work with MAF upgrades using the stock ECU or even with an ECU reflash.

With the RB, I wouldn't recommend it. Save up for a good engine management system and go about it the right way. You'll learn more than how to cobble together a system of parts that won't work together as well as if they were running in harmony under the control of a well-tuned ECU.

Yes, I just used the word "harmony" in a sentence.

[GSDKinked]

Im a little new to the nissan world but i figured i would see what you guys think about this idea of trying to avoid ecu tuning with power upgrades.

A rb25det Maf reads 0-5.12V.... and that is based from 0-4423 Flow UnitsUsing the stock 370cc injectors the computer needs no tune since it is all stock!

A z32 Maf reads same 0-5.12V ... but at a differnt flow rate of 0-7546 Units Since the rate of difference between them is .587

In theory "586cc injectors" ( i know they dont make that exact injector size) with a z32 maf could run perfectly on stock rb25det ecu? Right?

The ecu would be basically doing the same math without knowing the upgrades are installed.

If the factory ecu should run the injectors at the same rate of air it sees from the MAF. I think it would be compensating for the upgrades without knowing!

Has anyone done something similar to this?

We basically have the same set up. And all these guys are right, don't expect to beat on this thing as is. It's good enough to drive an put around on but not to romp. I have a JGY top feed fuel rail, Z32 TT ECU and soon a new FP regulator coming in. WAIT UNTIL YOU HAVE ALL THE NECESSARY PIECES TO THE PUZZLE BEFORE YOU DO ANYTHING. RBs are NOT cheap to build or REBUILD. Don't go blowing up an investment.

Stock injectors won't take you anywhere near the efficiency range of the turbo, hence why it is running like s*** when you romp on it. Just be patient and wait. All the fun comes in due time.

[dg_performance]

So if i got a z32 ecu.... what year z32 ecu should i go for? I got a 96 rb s2. If i am going to go this route i thing nistune would be the olny option.

Or should i save up a little more and buy the apexi power fc? Does this have more tuning capabliities that the z32 ecu? I kinda like that the PFC has the handheld device that i can look at anytime 2 c how things are running.

By going with the z32 ecu i should be able to run the z32 maf i already got with the skyline stock 370cc injectors right? I only have to repin the ecu correct? How many wires we talking about?

[GSDKinked]

So if i got a z32 ecu.... what year z32 ecu should i go for? I got a 96 rb s2. If i am going to go this route i thing nistune would be the olny option.

Or should i save up a little more and buy the apexi power fc? Does this have more tuning capabliities that the z32 ecu? I kinda like that the PFC has the handheld device that i can look at anytime 2 c how things are running.

By going with the z32 ecu i should be able to run the z32 maf i already got with the skyline stock 370cc injectors right? I only have to repin the ecu correct? How many wires we talking about?

I believe it is either 3 or 6 wires (someone correct me on this) and any TT ecu from 1990+. And you will have to have the ecu tuned for the injectors and maf still. And if you're running gauges, the handheld device for PFC is useless besides for changing things. And unless you plan on pushing the limits of your motor, it is completely unnecessary. Aussies are putting down 600 to 700whp in the forums with dyno sheets on Nistune. If that doesn't tell you the capabilities of the software I don't know what does.

[RustspecS13]

From what Ive read its 12 wires to change around. Really its not that big a deal since you get OEM reliability and huge power potential.

And you can use any Z32 ecu since you will change the base tune before you run your car.

~Alex

[dg_performance]

I contacted nistune and they recomended a 90-91 z32 ecu.... and i was told it does not matter if the ecu was tt or na or manual or auto. something about the ROM image on the nistune runs the ecu so ..... i guess any work.

i was told to stick with these certain range of numbers printed on ecu sticker. 1990-1992 (23710-30Pxx, 31Pxx, 37Pxx, 40Pxx,41Pxx, 46Pxx,47Pxx, 48Pxx)should make it pretty easy to find an ecu if a tt one is not needed.