First off, special thanks to Matt Pelto (Mardigrasmax) for supplying the injector and shipping it to RC Engineering for me.

Now here is the data that I just recieved via fax from RC.

Injector Type : SAT 14.9
Injector make : JECS
STDF : 315
Part# : FBJC1101 001 1705
Test Pressure: 52 psi (3.5 bar, standard in the 2002 Maxima)

INJ.#1
CC/MIN 315.0
Pattern Excellent

LBS. / HR. - STATIC: 30.00


Horsepower @ 80% Duty Cycle at listed BSFC

@ B.S.F.C OF .65 36.9
@ B.S.F.C OF .55 43.6
@ B.S.F.C OF .50 48.0


---------------------------------------------
And the flow rates at 3.0 bar or 43 psi

Injector Type : SAT 14.9
Injector make : JECS
STDF : 270
Part# : FBJC1101 001 1705
Test Pressure: 43 psi

INJ.#1
CC/MIN 270.0
Pattern Excellent

LBS. / HR. - STATIC: 25.71


Horsepower @ 80% Duty Cycle at listed BSFC

@ B.S.F.C OF .65 31.6
@ B.S.F.C OF .55 37.4
@ B.S.F.C OF .50 41.1

 

i'm pretty sure this is all good info...too bad i dunnoe wat all the numbers means...

 

Thanks Matt...how about the Z injectors now???

 

 

Can you break this down into layman’s terms for us common folks?

 

 

damn 315 isn't half bad...I know some cars that would kill to have stock injecotrs flowing like that.

 

Ive got a set for sale

 

english man.. english

 

Using 3.0BAR

95-99 Injectors are ~240cc
300ZX TT Injectors are 370CC

So 270cc is pretty good for a NA application even at 3.0BAR

At 3.5BAR they could support 288bhp at 80% duty cycle(open time)

 

I think this is what you were looking for Sprint.

 

I posted the data while at work and didn't have time to elaborate. And I figured if I left anything out I would get grilled.
The way I presented the data is easier to read than the papers I got from RC which would confuse you even more. These responses are funny because just as Matt sent the injector off I had about ten different people ask me if I knew how much these things flowed and at the time I had told no one what we were doing.

Just as Mardi said, @ 3.5 bar (52psi) these injectors are good for roughly 288 crank hp under very good conditions. 30 pounds per hour static flow rate is pretty big for a stock NA motor. Usually boosted engines have injectors that large.
But the interesting thing is that they're almost maxed out already. The last time Scott dynoed his car I hooked up a dwell meter and monitored the duty cycle of his injectors. His VQ35 took the injectors all the way to 80% duty cycle at 6300 rpm which is way too much fuel (see 288hp). And he only put down about 214hp at the wheels. He suspected that his car was running too rich and this partially proves that. He and I both ordered Apexi S AFC-II's to install and tune our cars hoping to improve the gas mileage.

As for the laymans terms check the numbers in bold.
VQ35 injecters. 30 lbs. 315cc or whatever floats yer boat.

 

Those are pretty good numbers, but we can't use the injectors in our car because they are a different type right?

Also since the Z/G have more hp would it lead one to believe that they have even bigger injectors to compensate for the extra power?

I'm really interested in the potential power for both VQ30DEs as well as VQ35DEs, but I'm still beginning to understand all the variables involved.
-hype

 

You can't use our injectors in your car because they won't physically fit. But you can use the 300ZX injectors since they're the same style. At least one person on the .org has done so :cough: Mardigrasmax :cough: and it seems to be working fine :cough: untill his next upgrade :cough: .

For those of you who really want to know about this stuff I highly recommend 'Auto Math' by John Lawlor. http://www.amazon.com/exec/obidos/tg...glance&s=books
It's a good read that one can learn alot from. I bought this book years ago and I still refer to it from time to time.

 

am I undertanding you right that Nissan makes the 2k2 run rich stock??

 

No im saying that his car runs too rich. Mine isn't as bad nor is blubyu2k2's car.

 

all your flows are belong to us

 

I can't speak for other 2k2 / 2k3 max's, however my car is running extremely rich. You can view my air / fuel graph HERE. Of course the Apexi SAFC II that I just ordered will change this!

 

TOYS!! YEAH YEAH!!!!

 

WOW!!!

 

YOU need to buy my car addae

 

you're telling me....I'm starting to go into modding withdrawl, plus riding the bus with these stanky *** crackheads is no fun gimme till June I should be back on the road in something!

 

Wow, dang. Is 14.7 optimal?

 

Yes, 14.75:1 is considered an ideal air / fuel ratio in order to achieve the best compromise between power and economy.

 

14.7 is called the Stochiometric ratio. The perfect balance of air and fuel. Of course you can't use 14.7:1 under WOT because the heat wil become too intense and melt metals. I don't see why these cars would need to ever run any more rich than 12.5:1 while making peak hp.
And just for a reference top fuel engines dump twice as much fuel into the chamber than there is air to burn. It literally takes that much extra fuel to avoid melting the aluminum.

 

Thanks for the clarification

 

Since he's probably going WOT, that's the Nissan closed loop ecu defaults? Man that is very rich.

 

I don't think it's Nissan's 'default' for the ECU. I have not seen anyone else's A/F ratio diagrams that look as bad as mine do. I just think with the combination of all my mods the ECU is 'confused' or something. Who knows. All I know is the SAFC II will help me fix this.

 

How is your mileage? If it sucks, I would seriously consider letting Nissan run a Consult diagnostic. Mods allow more air so if anything, it would be running leaner not richer. Plus the ecu and injectors should be able to compensate for any na mod you could throw at it. Maybe your base or WOT fuel pressure is off(ie.. too high)

 

I appreciate your advice. However if I'm adding more air flow and the ECU is not adjusting the fuel delivery to account for the extra flow, then you're right I would be running a bit leaner (assmuming the ECU's A/F settings are the same before and after I modded my car). I'm confident the ECU has adjusted itself based on my mods by giving me too much fuel ie. the terrible A/F ratio. I had the dealer check the MAF senser, O2 senser's, etc. just to make sure it wasn't something obvious such as this. Everything checked out 'ok'. They couldn't find any problems with my car. Another org member Studman, experience similar problems to me with his 2k2 after modding it. He started getting terrible gas mileage and discovered he was running real rich based on his dyno results. He bought the E-manage fuel device from Greddy to adjust his MAF senser reading going to the ECU. After doing so he gained about 7 HP and an avg. of 4 to 5 MPG. I'm confident the SAFC II will yield similar results for me.

 

And just you wait to let me show you all the cool things we're gonna do with them.