I have looked and I didnot find what I was looking for. I may have missed it, if I did flame me, but show me the post please.


If I were to upgrade to 370 cc injectors and z32 maf, can I leave my base FP @40 like it sits now with the walbro intank?

I understand that it will start, may run VERY ricjh, but it will start. I was thinking that doing this and removing the FMU and adding a SAFC would be ok.

I know alex reccomends keep the FMU at 4:1 (IIRC), for possible power loss, but I thought that was with base FP @ ~34psi.

With the factory FPR being 1:1 I thought with the upped FP and z maf it would be ok.

Any thoughts. Also if I am out of my mind please tell me. I have been swampped with info on several issues I am looking at.

 

Well with 370cc injectors and z32 maf you want to run 27psi, I would guess 40 psi is just too much.

 

To much for idle or start up or under no boost?

 

The Z32 MAF from my understanding with the 370s will run you 1:1 @37PSI something like that. Now you will need to bump up your FP a bit up top if not youll run lean. Thats the understanding I got.

 

You need to drop your *IDLE* fuel pressure from 34psi(stock) or in your case 40psi to roughly 26-27psi per the board members or you'll quickly foul your plugs/02s and could damage your cat long term ESPECIALLY during cold starts when the ECU dumps in excess fuel due to being in open loop.

Anyways, the stock 1:1 FPR ratio is ONLY to MAINTAIN WOT fuel pressure as boost rises(StephenMax pointed this out), ie you can't count on it for ADDITIONAL fuel. It simply increases fuel pressure to compensate/counteract the boost pressure on the other end of the injector so you end up with the *SAME* amount of fuel.

My recommendation is to lower the base fuel pressure using an adjustable FPR to the recommended 26-27psi, use the FMU to provide the additonal fuel necessary under boost, and the S-AFC for fine tuning ~0.5 AFR ratio on the dyno.

Again, the 1:1 FPR fuel pressure compensation should NOT be included in your ultimate fuel pressure needs unless you eliminate it, however then you must make sure you bump up your FMU ratio to compensate.

 

Ok, that is what I could not figure out. Thank you

Thanks Alex... I've have had too much on my mind recently to get it right.

 

There is perhaps some confusion in this thread that needs to be clarified.


370's, A32 maf, A32 ecu - Mardigrasmax did this, and ejj is running this setup presently. In this case you need to compensate for the increased injector flow at idle and closed loop operation by lowering fuel pressure to 26-27 psi. Boosted operation may require extra fuel, either by fmu or SAFC.

370's, Z32 maf, A32 ecu - I have experimented with this setup a bit. I found that the fuel pressure does not need to be lowered to have stoichiometric idle, and the ecu is able to provide stoichiometric afr in closed loop operation. Acceleration at a throttle setting of more than about 40% results in some leanness. WOT operation is way lean, and I had to compensate with an SAFC by adding as much as 25% from about 5000 rpm on. An adjustable fmu like the Cartech unit could be used effectively in this case.

370's, Z32 maf, JWT ecu programmed for the injectors and maf - you're golden.

 

Just curious how you measured the a/f at idle? Was it the voltage on the o2 sensors?

Thanks for clearing the air. So an FMU and SAFC would be best for WOT.

Ok, sorry to make you repat yourself.

Thanks again

And I'll be trying th MAF on the charged side as well.

 

I have a wideband O2 sensor that gives accurate afr information.

By the way, increasing maf voltage by 25% at the higher rpm resulted in an afr of 12.5:1 at WOT (370's, Z32 maf, oem ecu, oem base fuel pressure, 1:1 fpr).

 

Thanks for the correction Stephen.

bags,

I'd try and run 40psi to reduce/minimize the amount of AFC correction, *IF* possible. If not, you'll need an AFPR to bring idle fuel pressure down.

I still say go with the FMU, since ADDing fuel with the AFC also indirectly increases timing, which you definitely don't want in the mid/upper RPM. I'd use the FMU to provide more then adequate fuel(pressure) and the S-AFC to pull the excess, which indirectly retards timing.

 

I am sold on the FMU. I just need a 4:1 disk now...


I have a few new springs to help with the boost, thanks dixit

The goal is 9 psi and a MEVI and the SAFC

Then I hope for 330whp/tq

 

Ok, So I want to run an A32 ECU, 370's, and Z32 MAF. I have an FMU and SAFC. What FMU disk size or SAFC settings should I use to keep me safe until I get to a dyno to see my AF

Will do this soon

 

What would you want your Base FP to be at with this setup ?? 34 or 37 ??

-matt

 

base fp and 4:1 disc maybe? i just swapped the 4:1 in on friday. mike-if you need that one, sorry. you may even want to get the 3:1.

bags, how has it been working out for you?

 

I did 4:1 and settings of 2400 rpm + 20% ...... then like 4000-5400 rpm -8% and then from 5600 and above +8%


I would not go above 4500 rpm with the SAFC in and NOT tuned. With turbos being different and piping being different, to many variables, unlike the SC'ers.

Also, I found out changing the GND on the SAFC will cause the settings to change.. FYI

 

Yeah, I was running base FP and 4:1

It was working out great, until my POS turbo feed pipe broke in half. Now the turbo is off the car while I make a new feed pipe.

I am still running the Z maf and 400cc injectors on 40psi of base FP. I have a starting issue when it gets cold (40deg and below) and my car sits for ~8hr

Just have to feather the gas a little during start up and for ~20 seconds or so during warmup or it'll stall out and take FOREVER to start

 

i was thinking more stock fuel pressure (34 psi). I know that it is a little different since I am sc, but i'm doing a datalogging tune with the WBO2

 

I have stock FP, but the walbro pushes it up to 40 psi. That's the only reason I mentioned it

 

Time to wire in a push button start and remove the cold start fuel dump that's causing your problems...

 

not since it's warm outside..lol

 

I've got a pushbutton start, A32 ECU (with emanage) Z32 MAF and 370s and I have cold start issues as welll when its below 35-40deg. When I try to start it while the engine is cold and the ambient temp is cold, if I don't tach it up to 2500, it won't idle.

 

Neal-thats cuz we live in the arctic circle.

I'm glad that mike and i are going to try and do this with both s/c and t/c in close proximity so we can help each other out if there are issues.

 

Im wondering if you have a safc can you run a z32 with out having to do anything to the ecu. Will that work?

 

That's exactly what some of us are doing

 

ok to try to clarify this, your recommendation for a Z32 MAF, 255 Walbro intank, 370cc Injectors, A32 ECU would be an AFPR set up 27psi (or would the stock one give you an okay idle and cold start) and also a FMU (has someone found that the 4:1 works better than the 3:1 or vice versa)

Thanks,
also, is sard the best AFPR that has an adaptor for our cars?

 

if you dont get the adapter from the sard, you can get one from www.sx7r.com and use it with either an aeromotive or aem fpr. I would not go with obx EVAR!

Base fuel pressure with those accessories would be stock fuel pressure. Bags, did you ahve to wire in a push button start?