Ok.. after having had the pleasure of reading many old threads last night...

It's a given that one must get a recalibrated ECU with larger injectors (especially the 370cc/min 300ZTT ones) or these injectors would "wash out" the combustion chamber when in open loop.

4th Gen injectors are RED in color and flow approximately 240cc/min
4th Gen injectors are side/galley feed variety (vs. 5th Gen top feed)
4th Gen VQ30DE can use injectors from TT 300Z(i.e. 370cc/min) without fitment problems

Can anyone answer (or correct the facts above) the following questions?

What do the COLORS of the top of the injectors represent? (I assume they don't consistantly code for flow capacity)

Would NA Z32 injectors also be a "direct fit" on the 4th Gen? (I believe they are rated at 270cc/min?)

 

This is not true, take MardisGrasMax, he put 370cc injectors in his 4th gen Max and no ECU upgrade. Just recently dynoed it at almost 400whp running 15lbs of s/c boost.

Dixit

 

I thought he did use an ECU.. I qouted him from his dyno thread

" Using the G force NA ECU to ramp up the timing in the low and mid rpms gained ~15hp/15tq. "

NOT to say it is programmed for bigger injectors, but just trying to help

BTW dixit.. I am SO JEALOUS of your car

 

http://forums.maxima.org/showthread....ight=Injectors

That is the thread that shows that he installed them without upgrading the ECU. He did the Upgrade later for timing since he is running so much boost and to retard/advance timing for knock/ping control.

Dixit

 

I think there is also other injectors that are a direct fit for 4th gens, I think they were from a Silvia, but I could wrong, I don't have time to do a search right now, but I also believe they were larger than the 300z injectors......and Mardigras doesn't have any ecu for his injectors, the ecu adjusts to them but you have to lower you base fuel pres. to 20psi, and this would only be good for boosted cars because you need the fmu to get the psi back up because the fuel wont atomiz good at that low of a psi. Also I would say the 300z injectors are the biggest you could get away with the ecu compensating for. Hope I didnt post any wrong info.

 

He's using Fields AFC and adjustable FPR to trick the ECU.

 

The G Force ECU is for a normal NA Max with stock injectors.

The Fields dosent effect part throttle driving.

I lowered the base fuel pressure with an adjustable fuel pressure regulator. Their is a few threads about it, search is your friend.

 

Hi Matt! I think we can all concur that you are not the "Norm"... I remember your setup...including the tuning with the lower base FP and 3:1 disc...

I'm thinking the SE-R or NA Z32 injectors at 270cc would be more "friendly" a swap than the 370cc TT.

BTW - the question was not of the ECU mod but color code and compatibilitiy with NA Z32 injector...

 

Ahh.. ok.. thanks for the info. Man, keeping up with what he is doing is hard. And I am still wondering about some things.. but maybe time will help

Thanks again for correcting me

 

I hope you don't mind me asking a related question.

What is the minimum level of boost you can use the 370cc injectors along with the minimum 3:1 calibration disk for the Vortech fmu?

For instance, suppose you are running 9 psi of boost with a 6:1 or 8:1 disk in the fmu and stock injectors. Could you use the 370cc injectors with the 3:1 disk and not be running too rich, or is 9 psi not enough boost for that combination of injectors and fmu disk? Of course, you would have to use an adjustable fpr like Matt does to lower the base fuel pressure so that it won't be too rich at idle, and for fine tuning you would want something like the s-afc. But in general, at 9 psi, would the 370cc injectors along with the 3:1 disk flood the engine or not?

 

It would be too much.

 

Thanks Matt, even though that's not what I wanted to hear. So, to go with the 370cc injectors, I would need to either go to a smaller pulley size to make more boost, thus increasing the fuel requirement, or lean out the AFR with a s-afc? Or both?

Thanks.

 

Stock 350Z injectors are 300cc/min. Power Enterprise has 380 and 510 cc injectors available.

 

The problem is, they are probably TOP FEED like the 5th Gen so it wouldn't be a direct fit... 300cc ones would be cool , +12%

 

AFC for sure either way!