Actual size and lag time of s15 injectors

[Noakesy]

Hi all 

I have conflicting info about the stock s15 jap spec manual injectors

I require the correct cc and lag times for my apexi

 

I have seen cc range from 440 444 448 and 480cc

And as fo lag times .5 .583 .78ms

As well as confusing the nismo 480 with 1.100ms

 

My new injectors are 850cc with a lag of .780 at 14volt 

 

Are the stock lag timea measured at 14v also

I did speak with john at fc hacko and recomened i spoke with paulr33 

 

 

[GTSBoy]

Well, they're not 480, and it wouldn't matter if they were supposed to be 440, 444 or 448, as <1% difference is far smaller than the random tolerances anyway.

As to the dead times.....dunno. But the part numbers are well known and I have seen very good tables listing all Nissan injectors against part # and specs, which I', not going to google up now.

[Noakesy]

Thanks it more what the apexi wants. I have googled for a few hours with not much definitive as well as the apexi manual. So many people saying they are 480cc i dont belive it myself.

I will be going with the 448cc and .583ms

As a stab in the dark starting point

Im sure alot of people have been down this path. 

[joshuaho96]

On 11/18/2021 at 11:03 PM, Noakesy said:

Thanks it more what the apexi wants. I have googled for a few hours with not much definitive as well as the apexi manual. So many people saying they are 480cc i dont belive it myself.

I will be going with the 448cc and .583ms

As a stab in the dark starting point

Im sure alot of people have been down this path. 

I have recently sent my OEM RB26 injectors out for service as a part of preparation for California emissions. Also as a part of that because I really don't want to waste perfectly good o-rings 6 months down the road I asked them to test the dead time and all that fun stuff. The spec for the stock injectors at 3 bar was something like 480 cc/min, I got 500 cc/min on average. The OEM ECU reports 0.77 ms dead time, their testing reported closer 0.5 ms. I asked them multiple times whether that made any sense, especially whether 4 bar having roughly similar but slightly lower dead time was normal for old injectors. Their answer was yes. I haven't started engine map development yet so I can't say whether their report was truly accurate but something to think about.

[Ben C34]

Yeah nah.

That's my take.

[Noakesy]

Ita actually 4% difference from a 448 to a 480

Going to a 850

[GTSBoy]

1% difference was between the 3 sizes clustered around 444.

[Dose Pipe Sutututu]

480cc is when it's a 3.5bar.

Stock fuel pressure is 3 bar, they're in the 450cc range.

Also if you're tuning on an ancient GameboyFC ECU just adjust the dead time till you hit stoich with the idle fuel cells at 1.00.

Don't over think it.