Help me understand Z32 MAF + Larger injector

[maxima92se]

Ok before I start please read and understand the below Link. Its a nice explanation of the how the Z32 MAF works.

http://forums.maxima.org/3960772-post1.html

Now my question could be stupid but I am here to learn so here we go. From what that thread shows on how the Z32 MAF works, If was to run the Z32 MAF and a set of 440cc injectors, now here me out here, there might be a possibility that I can run 4in and 4out on a VAFCII for the sensor type and be able to run the car a little richer than normal under 3K rpms because if I understand correctly you cannot tune below 3K because the ECU uses stock set parameters and the car will run super duper rich with 440cc without AFPR.
Reason why I because I want to get rid of excess stuff in the bay like FMU and needing to get a FPR??

I will compare it to running DEK injectors on the 4thgen right?? because the Z injectors are 370cc iirc therefore I will be 70cc over but The DEKs are 290 vs 210cc on the DE and there is no need really for AFPR really??


Its like 2:20am and I am a little tired but I think that might work. If you have questions please let me know.

Thank you.

[98whitemax]

hey you got them injector sizes all wrong vq30de-k and vq35de have the same size injectors iirc. im 100% sure that 350z injectors are 290cc.
as th ins and outs i have to check again ill let you know on that.

[The Wizard]

As for the link you provided, it's all theory. I believed in what was said in that link and nothing proved to be true for myself.

I installed 550cc injectors and the Z32 MAF and my Max barely started and would barely idle. I had to keep my foot on the gas to prevent it from stalling.

Right before I installed the injectors and MAF, I installed the EMU and didn't change one parameter...ie let it run like stock. After I installed the injectors and MAF, I had no choice but to get it tuned by a pro. I had to drive one hour with the horrible conditions I mentioned above to the tuner shop of choice. When I got my car back, it started and idled like a champ, and drove like a raped ape.

[maxgtr2000]

z32 maf is good for 370cc injectors no afpr.
z32 maf w/ injectors bigger than 370cc and afpr w/stock fp just needs minimal adjustment.
z32 maf and injectors bigger than 370cc and no afpr needs tuning/scaling.

I think people wanting to do set ups get confused. FMUs were used with supercharger kits because there was no engine management. Just bolt everything on, hit boost, the fmu raises the fuel pressure, makes the stock injectors perform like bigger injectors. Proper engine management can increase/decrease the injector pulse to put you where you need to be.

Proper fuel management is something like an emanage ultimate that can scale down the larger injector pulsewidth. I'm not a fan of vafc/safc since timing is also a factor in boost, especially in turbos, in s/c they are ok. Emanage blue can handle larger injectors but the scaling effects timing indirectly. On the blue you can run an afpr and do the scaling that doesn't effect timing as much. An afpr raises your fuel pressure (1:1)in boost and will allow you to run stock fp with larger injectors.

If you want to stay with the vafc/safc get an afpr , set it to the stock fp (or less) and tune from there.

[maxima92se]

Originally Posted by 98whitemax

hey you got them injector sizes all wrong vq30de-k and vq35de have the same size injectors iirc. im 100% sure that 350z injectors are 290cc.
as th ins and outs i have to check again ill let you know on that.

Sorry. i was talking in reference to the VQ30DE.

[maxima92se]

Originally Posted by maxgtr2000

z32 maf is good for 370cc injectors no afpr.
z32 maf w/ injectors bigger than 370cc and afpr w/stock fp just needs minimal adjustment.
z32 maf and injectors bigger than 370cc and no afpr needs tuning/scaling.

I think people wanting to do set ups get confused. FMUs were used with supercharger kits because there was no engine management. Just bolt everything on, hit boost, the fmu raises the fuel pressure, makes the stock injectors perform like bigger injectors. Proper engine management can increase/decrease the injector pulse to put you where you need to be.

Proper fuel management is something like an emanage ultimate that can scale down the larger injector pulsewidth. I'm not a fan of vafc/safc since timing is also a factor in boost, especially in turbos, in s/c they are ok. Emanage blue can handle larger injectors but the scaling effects timing indirectly. On the blue you can run an afpr and do the scaling that doesn't effect timing as much. An afpr raises your fuel pressure (1:1)in boost and will allow you to run stock fp with larger injectors.

If you want to stay with the vafc/safc get an afpr , set it to the stock fp (or less) and tune from there.

Thanks for the info. Ive had 440cc injectors with me even before I got the SC and never installed them. EU was an option but looking up feature etc seems like Eu has way more than I ever need. I just need a good reliable set-up. I want to get rid of that FMU and run something more reliable.
If you are familiar with the VAFCII or similar can you pull fuel from the motor i.e control larger injectors I read somewhere that the ECU can adjust for 14.7 in closed loop but if it cannot can one pull fuel to aid the ECU in adjust for stoich??

Thanks.

[Nealoc187]

Originally Posted by maxgtr2000

Emanage blue can handle larger injectors but the scaling effects timing indirectly. On the blue you can run an afpr and do the scaling that doesn't effect timing as much.

That is not accurate.

If you tune on the Throttle Position map is the only way what you said can hold true with EB. If you tune it correctly (i.e. on the proper map, which the TPS map is not) timing is not affected in any way by IPW changes.

Tuning on the TPS map is equivalent to tuning with SAFC with regards to timing changes, but the TPS map is meant to be used for minor corrections to driveability throttle positions, not for in-boost tuning. In boost and at throttle positions over 25% or so, the TPS map cells should all be zeros.


With regards to I30tMikeD's post - I don't know why some people couldn't get it to work but he did. He's one of my good friends and I rode in, drove, and worked on that car many times. I was listening and laughing while Jim Wolf himself told mike that what he was doing (555cc w/ Z32 maf and stock ECU) was impossible. The simple fact was that the car ran MUCH better with that setup and a stock ECU (which was my ECU by the way, my old ECU out of my wrecked 96) than with the JWT ecu which was specifically tuned for Z32 MAF and 555cc injectors. Stock ecu also made like 70whp more on the dyno than the JWT ECU did with that setup.

[maxgtr2000]

I don't use tps. Once you put in the injector value the emanage blue scales the injector by lowering the maf signal, the lower maf signal causes the ecu to lower ipw and advance the timing. My timing was slightly advanced when I looked at it on an obdII scanner and I have 370cc injectors. My current air/fuel map values only have a range from -1 to -4 (-4 @idle). That's one reason the maf voltage in and maf voltage out never match up even if the airflow map is all zeros because of scaled injectors.

To the OP. A32 ECU, Z32 MAF, 550 inj and 10psi results

Originally Posted by Nealoc187

That is not accurate.

If you tune on the Throttle Position map is the only way what you said can hold true with EB. If you tune it correctly (i.e. on the proper map, which the TPS map is not) timing is not affected in any way by IPW changes.

Tuning on the TPS map is equivalent to tuning with SAFC with regards to timing changes, but the TPS map is meant to be used for minor corrections to driveability throttle positions, not for in-boost tuning. In boost and at throttle positions over 25% or so, the TPS map cells should all be zeros.


With regards to I30tMikeD's post - I don't know why some people couldn't get it to work but he did. He's one of my good friends and I rode in, drove, and worked on that car many times. I was listening and laughing while Jim Wolf himself told mike that what he was doing (555cc w/ Z32 maf and stock ECU) was impossible. The simple fact was that the car ran MUCH better with that setup and a stock ECU (which was my ECU by the way, my old ECU out of my wrecked 96) than with the JWT ecu which was specifically tuned for Z32 MAF and 555cc injectors. Stock ecu also made like 70whp more on the dyno than the JWT ECU did with that setup.

[mastercater7]

IMO and judging off of my own experiences, the z32 MAF and JWT ECU is a great way to get a good solid tune. I have had zero problems with my tune and it is always a solid 11.5 AFR unless I turn the fuel pressure up or down. I have tried other tuning options but still prefer the JWT z32 tune. As long as you aren't planning on other major modifications, this setup would work great. Also with the MAF detecting boost, you can adjust boost levels (until you reach the MAF's max) and the ECU will adjust accordingly; even with a stock ECU. If my car wasn't driven daily, I may have gone a different route. I am running 600cc injectors on a VQ35 and have the extended rev program. I doubt I will run boost with the MAF on the non-charged side again.

Nealoc- That is interesting that he managed to run the 550's with z32 and a stock ECU. Did he run an AFPR as well for minor fuel adjustments? My car also did not run with the stock ECU and z32 MAF; however I was running 600cc injectors on a VQ35 swap. I had an EMU at the time and had everything set at zero. As soon as I made the injector size adjustments, the car ran fine but I still needed a tune. Ever since I went with JWT I have had zero tune issues.

My $.02, hope this helps!
Zack

[I30tMikeD]

HA! Have not been on this forum for a long, long time and when I do I see a post about my old turbo I30. Gotta love it.

Z32 MAF, 550's, stock ECU, and SAFC worked good for me. What the OP stated did not makes sense. 450's and Z32 MAF? Did he mean A32 MAF?

[maxgtr2000]

Originally Posted by I30tMikeD

HA! Have not been on this forum for a long, long time and when I do I see a post about my old turbo I30. Gotta love it.

Z32 MAF, 550's, stock ECU, and SAFC worked good for me. What the OP stated did not makes sense. 450's and Z32 MAF? Did he mean A32 MAF?

(Z32) 300zx maf.

[Shadow]

When I had my car, I ran 670cc injectors (the biggest ones Deatschworks had at the time) with a Z32 MAF, emanage blue (only one available) and stock ECU. At the time, there wasn't an aftermarket ECU for the '97+. I had a SARD FPR and turned down the fuel pressure to ~26psi at idle. The car idled a little bit lumpy, but the rpm's stayed level. There wasn't bogging or anything like that. The only thing I had to do was to install a push button ignition; otherwise the car would flood on warm starts. The car also ran just fine, if I stayed off boost, I got ~20mpg.

I tried a lot of different fuel setups and the last one with big injectors was probably the best way to go for me. I had:

Stillen SC w/ T-rex fuel pump, stock injectors, and Vortech FMU. This was fine for the SC, but it ran rich at the top end. Eventually the wire for the fuel pump came loose (crappy shop install) and the car ran lean. This eventually cost me a motor.

Turbo w/ 370cc injectors, Walbro 255, stock MAF, BEGI FMU, SARD FPR, emanage blue. This was how we setup initially w/ the turbo because I couldn't find bigger injectors. Again, it worked fine and made good power. But we ran out of both injector and maxed out the MAF voltage at ~4500 rpm so were basically tuning with the adjustable FMU. Car ran rich like this, but it did work.

Finally we put in the 670 Deatschworks (well, really 665-667cc's) and a Z32 MAF. We turned the idle fuel pressure down to ~26psi, otherwise we couldn't start the car most of the time since the injectors would flood the motor. Also, lowering the FP allowed the car to idle since the stock ECU couldn't manage the big injectors and the emanage couldn't do anything at idle. The emanage was able to scale the injectors since the Z32 was set up for 370cc's so we were still within the range. This setup had the best A/F graph in that it remained almost flat and we were able to control it with the emanage.

If possible, I'd avoid FMU's just because the make it hard to tune and it's one more thing that can fail.

[maxima92se]

Originally Posted by Shadow

When I had my car, I ran 670cc injectors (the biggest ones Deatschworks had at the time) with a Z32 MAF, emanage blue (only one available) and stock ECU. At the time, there wasn't an aftermarket ECU for the '97+. I had a SARD FPR and turned down the fuel pressure to ~26psi at idle. The car idled a little bit lumpy, but the rpm's stayed level. There wasn't bogging or anything like that. The only thing I had to do was to install a push button ignition; otherwise the car would flood on warm starts. The car also ran just fine, if I stayed off boost, I got ~20mpg.

I tried a lot of different fuel setups and the last one with big injectors was probably the best way to go for me. I had:

Stillen SC w/ T-rex fuel pump, stock injectors, and Vortech FMU. This was fine for the SC, but it ran rich at the top end. Eventually the wire for the fuel pump came loose (crappy shop install) and the car ran lean. This eventually cost me a motor.

Turbo w/ 370cc injectors, Walbro 255, stock MAF, BEGI FMU, SARD FPR, emanage blue. This was how we setup initially w/ the turbo because I couldn't find bigger injectors. Again, it worked fine and made good power. But we ran out of both injector and maxed out the MAF voltage at ~4500 rpm so were basically tuning with the adjustable FMU. Car ran rich like this, but it did work.

Finally we put in the 670 Deatschworks (well, really 665-667cc's) and a Z32 MAF. We turned the idle fuel pressure down to ~26psi, otherwise we couldn't start the car most of the time since the injectors would flood the motor. Also, lowering the FP allowed the car to idle since the stock ECU couldn't manage the big injectors and the emanage couldn't do anything at idle. The emanage was able to scale the injectors since the Z32 was set up for 370cc's so we were still within the range. This setup had the best A/F graph in that it remained almost flat and we were able to control it with the emanage.

If possible, I'd avoid FMU's just because the make it hard to tune and it's one more thing that can fail.

Thanks for the info. I guess I am just going to be playing with different fuel set-ups. I am hoping of running the 440s, Emanage ultimate and AFPR. Pull the FMU and VAFCII. hopefully this will work. Right now I have the Z32 installed and Its running like shyte at idle. The A/F at idle is around 16-18. Very loopy and the car stalls big time. This is running the Z32 MAF at 2in 4 out. If i run it at 5in 4out, the car idles perfect 14.7-14.9 but its goes pig rich as soon as you tap the gas Below 9(Zeitronix can only read that low). At 2in, 4out it idles horribly but once i get on the gas (still need to tune) its around 10.2 but pulls like a bat out of hell. I wont tune till I figure out the idle issue.