I mentioned a couple of weeks ago that I found that you can run the Z32 maf and 370 cc/min injectors at stock fuel pressure along with the unmodified A32 ecu with apparently no problems.

Last week I did an extended test where I ran that configuration for about 5 days. There were absolutely no problems in closed loop operation and open loop at startup.

I did find, however, that I would get detonation when boosting at WOT with a heat soaked engine. Boosting with the engine warm (but not hot) resulted in no discernible pinging.

I think it may be a timing issue since egt's were in the low 1400s, about where they are with the JWT ecu.

 

So, you think the detonation only occurred becuase maybe of a timing issue? Hmmmm, interesting. So, you think that with the combo of the 370cc injectors, Z32 MAF, and no FMU at stock FP, we would be ok in the long run, or should we still utilize an FMU at a very small boost ratio disk?

You the man Stephen.

 

I think it may be a timing issue, but I'm not sure. The egt didn't seem to get any higher than what I'm used to seeing with the JWT ecu. I should have tried to adjust the afr downward with the SAFC to see if I could tune the detonation out. I'll try that this week sometime. At any rate, it would definitely be a good idea to have some way to adjust afr downward at boost when going with this setup. Either SAFC or Cartech fmu.

 

So to run 740 cc injectors you could run the JWT dummy maf set up like on the TT Z?

Make a Y going into the manifold, on one side is a z32 maf, on the other is a dummy maf not hooked up. both have the same filter. So the working maf is only meatering half of the incomming air. The 740cc injectors are 2x the size of the 370s, So this might work for those who need more than the 370's. Nad dont want a true JWT set up. Timing will be an issue, nothing a J&S couldnt handle.

 

Nice observation. And maybe you could run 555 cc injectors with a dummy maf that has 50% of the flow area of the metering maf?

 

Any chance at getting it on a Dyno to see what the A/F is doing? Nice work btw.

 

*bump*Missed this one*bump*

Instead of a dummy MAF/Y-setup, couldn't you hack out the A32 MAF element and epoxy it into a PVC pipe of the desired proportional diameter?

Can either of you measure the ID of the A32 and Z32 MAF tube for me?

Thanks.

 

to get more fuel delivery at the stock fp, would you run 555's?

 

I'll have to measure to be absolutely sure, but I'm very sure it's 70mm. Final answer.

 

Just to confirm what you've said in another thread, both the A32 and Z32 MAF have the same ID, correct?

 

Yup, they are exactly the same ID as each other, and the ID is 2 7/8" which is 72-73 mm.

 

Thanks........

 

So for those with a 99+ who can't get the JWT, it sounds like it's feasible to run the Z32 MAF and stock ECU with no FPR, as long as you've got a J&S to keep tabs on the timing?

 

A hacked MAF is one of the best bang for the buck fuel control methods for forced induction. Simple, easy to calculate, and all it takes is some skill taking things apart and putting them back together...

 

You still need a FPR, but if you meant FMU, yes.

However, I'd still run a FMU, but with a 2:1 or 3:1 ratio if not using 555cc injectors.

 

Thanks, I think that's what I meant Please bear with me as I'm still learning the whole boost game.

FPR = fuel pressure regulator... used to adjust base fuel pressure?

and

FMU = fuel management unit... used to increase fuel pressure based on boost, with 2:1, 3:1, etc. equating to the increase in psi of fuel pressure per pound of boost?

Here's an excerpt from Stephen Max's original Z32 MAF/370cc injector thread...
So would I run the 2:1 or 3:1 just to make sure I don't run lean? If the 370cc injectors are 54% bigger than stock, and Z32 MAF reports 49% less air than stock, wouldn't I run a little rich due to the 5% difference?

 

yes, no, maybe so?

 

Maybe. The correlation of voltage at a particular air flow between the two mafs has not been established. What I mean is, the Z32 maf can measure 49% more total air flow than the A32 maf, but that does not mean that the voltage is always 49% less than what an A32 maf would give for an arbitrary air flow.

Now that I have the wideband O2 sensor hooked up with rpm and throttle position input data logging, I'm going to switch the A32 ecu back in and find out what SAFC adjustments are needed to produce a safe afr. Stay tuned.

 

If the maf in question is the same as the 89-94 maf's I have the vq map for it and the vq map for the z32 if anyone wants to see the differences in flow.

 

What do you mean "vq map"?

eManage map?

 

im pretty sure the 3rd gen and 4th gen MAF's are phisicaly different

but that dont mean there electronicly different

 

Nissan uses a "voltage quanitfier" map to convert the voltage output to a 16 bit number that the mpu uses to determine load. Each address, 64 in total, is a .08 voltage step. .08*64=5.12. The z32 maf is the same from 90-96. I have the binary file for a 89+90 max ecu as well. Does the 4th gen have an eprom or memory chip?

 

Done. refer to http://forums.maxima.org/showthread.php?t=288529

 

Hey everyone sorry to cut in but i have a 2003 maxima se auto and i am ready to start doing some modifications and dont know where to start.I just threw a rod on my 90 eclipse gsx turbo and have all left over parts from it but dont think anything could be used om my maxima,maybe the evo 560 injectors idk.I was wondering if there is a good maf/injector combo that would be an upgrade for my 3.5 that wouldnt require a ton of tuning.I do have a safc2 and w/b so i could tune if necessary.Does the injen cia make noticeable gains with headers, exhaust,and high flow cat or would going to a different maf/injector combo with exhaust be more effective?I guess i just dont know where to start but the car has 255 hp stock so this should be fun.