Q45 injector differences.

[280zx2by2]

Ok from my research all I have concluded about these injectors is that nissan forums are full of people who spread inaccurate info like wildfire...


But 94-96 purple tops seem to be what people are guessing are the ones the work when looking for a replacement 370cc+ junkyard injector for stock SR fuel rails...

My question is why?

94-96 Brown tops slide in just fine.

97+ Red tops slide in just fine.

Is it that they downed the flow of the red/brown tops?

[hobbs]

As far as USDM model cars go only two have used 370cc sidefeed injectors, the Q45 and Z32 300zx. Both models use 'phase one' and 'phase two' injectors depending on the model years. The 'phase one' injectors will NOT fit into stock SR/KA fuel rails and you need to be careful when buying/looking for these injectors, not all 370cc injectors are the same.

What should you be looking for when in a junkyard looking for 370cc replacement injectors? Later model 300zx switched over to the 'phase two' injector styles and are identified by the clip and a purple color injector. 'Phase two' injectors use a push style clip and not the earlier slide on plug with the U style retaining clip.

Also for the Q45, look for cars with the big chrome grill, these will have the tan/grayish top 370cc injectors that will also work in stock SR/KA fuel rails, you will need to remove the intake manifold to get at all of the injectors so expect to spend some time removing that but the effort is worth the pull, you end up with two sets of 370cc injectors.


Phase one injectors look like this:
http://www.gordonrichards.net/300zx/injectors.gray.purple.jpg
Note the retaining mechanism, slide on plug with metal retainer!


Phase two injectors look like this:
http://images.gasgoo.com/MiMwMDJfMDAyIzY4MTM2NzEwMA--/auto-part-370cc-fuel-injector-for-nissan-300zx-16600-21u01.jpg
Note that this style uses a built in plastic locking clip in the injector plug its self.


As for the red 259cc injectors you can find in almost any 90's nissan(sentra,maxima,G20,NA 300ZX) they will not supply much fuel other than about 180whp before you start to max them out.


TLDR:
-Phase two 300xzTT purple tops are 370cc and will fit into a SR/KA fuel rail just fine
-Phase two Q45 tan tops are 370cc and will fit into a SR/KA fuel rail just fine
-KA24DE,SR20DE,VG30DE are red top and 259cc and will fit into stock fuel rails just fine
-Q45 and 300zx phase one injectors will NOT fit into a stock fuel rail and will NOT plug into a stock KA/SR harness.

Also for future reference:

--------------------------------------------------------------------------------

This is a conservative rating at 3 bar. * indicate side feed or top feed inj sizes that can be bought from Nissan, Nismo or Tomei. Alot of the sizes you can not get but are there to help you if you are looking at a cetain flow rate by going to 4 bar.


3 BAR = 44 PSI, All the Nissans with Fuel Presure Regulators operate at 3 bar.

4 BAR = 59 PSI Running at 4 bar is better than running at 3 bar. Here is why, you can get more WHP from your inj at 4 bar, there is no xtra cost for a 4 bar program from JWT, you get better drivability at 4 bar because of better fuel atomization and you car will do better at the emmisions station becasue of better fuel atomization.

All Nissan Side feed injs are high impedence

For Low Impedance injs use 6.8 ohms 10 watt resister

The GTIR 444cc Inj is low impedence

91-99 USDM SR20DE = 259 cc side feed injs
00-02 USDM SR20DE RR = top feed injs

U12, U13, W10 and W11 SR20DET = 370 cc Side Feed injs
Pulsar GTIR SR20DET = 444 cc Top Feed injs

S13 and S14 RWD SR20DET =370 cc Side Feed injs
S15 RWD SR20DET = 444 cc Side Feed injs

SR20VET = 444cc Top Feed
SR20VE 20V = 350cc Top Feed
VR38DETT = 555cc Top Feed

Side Feed Injs

23 cc = 16 WHP
46 cc = 31 WHP
93 cc = 63 WHP
139 cc = 94 WHP
185 cc = 125 WHP * Pink GA16
---------------------------------------------185 cc @ 4 bar = 142 WHP
231 cc = 156 WHP
259 cc = 175 WHP * Red SR20DE
---------------------------------------------259 cc @ 4 bar = 203 WHP
278 cc = 187 WHP
324 cc = 218 WHP
333 cc = 226 WHP * Grey SR20VE
---------------------------------------------333 cc @ 4 bar = 261 WHP
370 cc = 250 WHP * Purple SR20DET
---------------------------------------------370 cc @ 4 bar = 290 WHP
416 cc = 281 WHP
444 cc = 305 WHP * Brick Brown SR20DET ( S15 )
---------------------------------------------444 cc @ 4 bar = 351 WHP
462 cc = 312 WHP
509 cc = 342 WHP
555 cc = 373 WHP * Yellow
---------------------------------------------555 cc @ 4 bar = 423 WHP
570 cc = 380 WHP * BLUE R35 GTR
---------------------------------------------570 cc @ 4 bar = 440 WHP
601 cc = 405 WHP * Yellow Tomei
---------------------------------------------601 cc @ 4 bar = 457 WHP
647 cc = 436 WHP
692 cc = 468 WHP
740 cc = 500 WHP * Red
---------------------------------------------740 cc @ 4 bar = 580 WHP

850 cc = 570 WHP SARD
---------------------------------------------850 cc @ 4 bar = 660 WHP

Nissan Top Feed Injs

350cc = 240 WHP * GREEN SR20VE 20V P12

444cc = 299 WHP * YELLOW RNN14 GTIR

444cc = 299 WHP * YELLOW SR20VET

570cc = 380 WHP * BLUE R35 GTR




MSD Top Feed Injs

36 lb = 250 WHP
50 lb = 355 WHP
72 lb = 520 WHP
96 lb = 690 WHP

MSD Injs do not run right at 4 bar so don't try it.


04-07 Subaru STI Yellow Inj
520 cc = 350 WHP

[280zx2by2]

What about the redtop phase 2 injectors from 97+ Q45's? Are they the same cc as later redtop phase 2 injectors?

[hobbs]

No idea, pull one from a junkyard car and spend the 20 bucks to get it flow tested, may turn out to be another big(370cc+) injector.

[280zx2by2]

Haha I could care less. I just need something that works so I can get my SR running healthy before I go to 550cc+.


Thank you very much for the help and info.