sleepermaxima

iTrader: (2)

In preparation for my V2 install I have installed most of the upgrades for the fuel system. 370cc injectctors, AEM adj FPR and Z32 MAF. I just finished installing all of this plus a fuel gauge tonight. I took it out for a test drive and it seemed to run great but I got a considerable amount of knock (very audible) whenever I gave it more than 50% throttle.

I tried running with 26 and then 32 psi base pressure; even though the narrow band A/F reads rich during idle if I have it set to anything above 18psi base.

The pressure increased by about 8 psi between WOT and idle.

Could this knock be caused by running the wrong sized orifice in the FPR? I left the smallest one in there. Should I go with a larger one?

Could this be a problem with the 54% larger than stock MAF and the 47% larger than stock inectors? (those are the figures I read on a StephenMax thread somewhere IIRC) In which case I need to compensate by installing this SAFCII I have laying around? May sound silly but I would like to make sure I have not messed up this install and leave the SAFCII install as a last resort. I would like to get this set up to work without it if possible.

TIA,
D

Stephen Max

iTrader: (59)

If you are using the Z32 maf you shouldn't lower fuel pressure any. Keep it at 34 psi idle.

The tuning I did with a wideband O2 sensor showed perfect stoichiometric at idle and partial throttle cruising with 34 psi base fuel pressure. Acceleration at anything over about 45% throttle showed it going lean (which is why you were getting detonation). I found that it took a correction of +25% at high rpm with the SAFC to get the afr down to 12.5:1 and eliminate detonation. I have the correction values vs rpm somewhere in a thread, I'll have to look for it.

Prodeje79

I am about on the same boat as you, except I am still looking for a z32 maf and waiting for my JWT ecu to get back to me.

Where did you mount the z32 maf for now?

Where are you going to mount it once you install that sc?

Any pics? :>

Oh and do you have the hook up on a z32 maf? :>
The best I can find is $100 shipped for a guarenteed working unit.

sleepermaxima

iTrader: (2)

Thank you sir

Do you mean that this FPR was all for nothing? This is the first I have ever heard of this. I wish the search feature was working for more than 3-letter words again.

If you can get those numbers to me that would be great. Just let me know what PSI you were getting at the time if you were boosted (Remember that this setup is still NA). I'm going to install the SAFCII today (right now I hope) and order the wideband kit today as well.

Does anyone know anything about which orifice I'm supposed to be using in the fpr? Seems like no one talks about it... could it be that it doesn't matter?

Thanks,

Derrick

Bags

iTrader: (3)

Look on page 3,4, or 5 in this forum it's a thread stephen started

sleepermaxima

iTrader: (2)

I mounted it exacly where I had the A32 MAF. This is a pic of my old MAF... it's hiding behind the battery connection. I plan on running this MAF in the charge pipe . Reason being, I want to vent the BOV to atmosphere and not have to recirculate it back.

I have not taken any pics other than in its most dissasembled state. I can snap some off if you want.

I do not have a hookup for the MAF... wish I did. It was a B***H to find. I paid about 120-130 I think. It was used of course. You'll need a Z32 MAF harness. Let me know if you want one, I have a spare one that is a liitle beat up.

I wish you luck getting the ECU back. I stopped trying to contact them a while ago. I'm determined to get this running perfectly under boost without it. Sometimes, I like a challenge.

D

sleepermaxima

iTrader: (2)

Thank you bags. Found it.

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

D

Prodeje79

I would like to get that harness, I went to a junkyard this weekend and did not find anything. :<

Aren't you worried about using the z32 maf on the charged side?!?!?!
I would hate to lose such an expensive part!
I know Stephen is running it on the charged side, but JWT flips out if you tell them that. It would make life so much easier if I just did it this way.

I hope to get my ECU in a week or so.

I guess my main interest is to see a setup using the z32 maf on the non-charged side.

Thanks!

Stephen Max

iTrader: (59)

Five months and counting on the charged side, boosting to 10-11 psi pretty regularly and I've had it up to just over 12 psi once or twice. Keeping my fingers crossed, but I also have a spare.

Prodeje79

So has anyone done this the "JWT recommended way"?

I figure if I have to make custom piping, I might as well do this the recommended way?

Stephen Max

iTrader: (59)

If you can get the maf far enough away from the blower inlet it would work better than what I initially did, which was to put the maf in the wheel well ala CAI.

I believe the Stillen SC kit for 5th gens incorporates a pipe that leads from a remotely located maf to the blower inlet and lays on top of the charge air pipe that leads from the blower to the throttle body. So the maf is somewhere over by the battery and is sufficiently isolated from blower backflow. Something like that would have to be done.

Prodeje79

So why can I not just use my 5th gen kit as is, since I am using the z32 maf?

I do not want to hack my kit, so I was going to make all new pipes. That way I could eventually sell it as a 4th and 5th gen kit if I ever went turbo.

I guess Jay25 would know the answer.

I need to see some better engine bay pics of the SC installed on a 5th gen to understand this.

IceY2K1

iTrader: (3)

Kev and many others have tossed the "MAF pipe" and made a CAI in the fender as you describe Stephen.

I don't see how that would cause you problems and not them.

sleepermaxima

iTrader: (2)

I'll PM you pics and details about the connector. Expect them in a day or so.

I am not too worried about it. As far as I understand MAFs, if I watch the voltage on the maf, making sure it does not break 5V or stay elevated for too long it should not have a problem. Someone, correct me if I'm wrong. Stephen, what are you getting at 12 PSI? I'm going to start with the 2.8 pulley so I would like to know what to expect.

I think JWT has a point. As a rule, don't run the MAF on the charged side... it will be safest to keep it upstream from the blower. Furthermore, I think they have a list of mods that can pose as gremlins to their ECUs; which they emphatically refuse to support. But nonetheless, it's mine and I want it my way. So I'm charging the MAF and watching it closely.

D

sleepermaxima

iTrader: (2)

Just an update, I have installed the SAFCII the night before last. I thought I would not have to up the levels all that much... but I was wrong. I finally got the motor to stop knocking (audibly) after I bumped the correction factor up to about 35%. I'm thinking about "hacking" my old MAF to make it better suit the injectors.

I've ordered the wideband O2 kit from innovate yesterday. I don't like the "cross my fingers" method of tuning I've been using fo far.

Prodeje79, I have not forgotten about you. Sorry. They'll be coming shortly.

D

Stephen Max

iTrader: (59)

You mean maf voltage? If I remember correctly, about 4.3-4.4V. I have the data stored in my computer at home, I think. I typically see about 4.25V at 10-11 psi.

Prodeje79

Sorry for the question here.

So one fries a MAF sensor by exceeding 5v?

I wonder what volatage people see with the 2.87 pulley?

Stephen Max

iTrader: (59)

No, it's just that the MAF sensor can not generate a signal larger than 5V to send to the ecu. By design, 5V means maximum measurable air flow. Boosted people with oem MAF sensors are regularly hitting the 5V limit, which is why they use a fmu to increase fuel pressure in order to deliver the additional fuel needed (since the ecu can't increase injector duty cycle anymore after the MAF sensor is maxed out).