JAY25

iTrader: (38)

Okay unfcked the spiking issue after a 13.4 PSI run on the freeway WTF! and got a CEL with that. Came home hooked up the Scan tool read the codes and reset it. Turned the car back on and set the gain down to 50% worked it up to 56%. Very smooth boost now. I still spiked to 9.9 but thats fine with me.

IceY2K1

iTrader: (3)

What were the codes? Lean code?

Try playing with the boost ratio too, ie lower it while slowly increasing gain and monitoring overshoot.

JAY25

iTrader: (38)

bank 2 lean. The 370's is whats saving my azzz. I have to do more work on this car to get it running like my SCed car.

Ill update you guys about this SBC-ID. Theres some hoses I am going to shortened and the location. Also this Boost controller takes two readings. I am going to get my 2nd reading elsewhere.

IceY2K1

iTrader: (3)

If the ECU saw it, you know it was lean as hell.

What FMU disk or ratio are you running?

JAY25

iTrader: (38)

My FP is high as hell, w/the 370's on purpose its at 50KPA. thats a bit over 65PSI. plus I I have my SAFC on positive numbers after 6K. EGTs did not even hit 750C, they are below that. Ever since I installed my 370s I never seen 800C. Car runs fine. it was for a split second remember once it reads spike it knocks that PSI down immediately.

Redmax

iTrader: (20)

Jay i am a little confused when it comes to fuel pressure, so why is it that you are running higher fuel pressures?

IceY2K1

iTrader: (3)

370cc w/65psi is good for ~433bhp(100% DC). ASSuming you're running a A32 MAF, you were at 100% DC.

Considering you put down 325whp@~10psi with an additional 3.4psi, that's around 350-360whp and 433bhp is ~368whp.

I'd say you cut it close.

[edit]
BTW, your SAFC setting above 6K rpm aren't doing anything, since your MAF is max'd at 350bhp.
[/edit]

IceY2K1

iTrader: (3)

Since he's no longer got an airflow referenced system(A32 MAF is good for ~350bhp), his injectors are at 100% duty cycle and he must increase fuel pressure to force more fuel through the injectors.

JAY25

iTrader: (38)

because I am spiking all the freaking times so I have not even installed the other FMU yet, until I get this issue resolved. I thought I did fix it, but I guess it did not. I believe the day I thought I fixed it the temp dropped the next day and maybe thats the only thing I can figure out. I am going to do more things to get this module closer to the waste gate. Ill let you know the deal when I am done.

JAY25

iTrader: (38)

i am not trying to boost 13PSI, I am just trying to get 9.7, maybe a spike to 10 would be cool but thats it right there.

IceY2K1

iTrader: (3)

Jay,

I'm not trying to bash you, but why the hell aren't you running a Z32 MAF yet?

You could definitely benefit from one.

JAY25

iTrader: (38)

is that **** plug and play or what? Dont I need a JWT ECU for the program?

IceY2K1

iTrader: (3)

Not exactly, but from the sound of it, your brother, StephenMax diagram, and 10mins. is all it would take.

NO~!

nismology

iTrader: (8)

So do the 370's have the ability to flow more fuel than the A32 will allow it to when it's maxed out, say with a Z32 MAF? I'm just trying to figure out if his injectors are at 100% DC because the MAF is maxed out, or because of the injectors physical inablility to flow the amount of fuel needed at stock fuel pressure... Are the injectors, the MAF or both the bottleneck in his system?

IceY2K1

iTrader: (3)

The A32 or Z32 MAF will peak at a certain voltage, say 5Volts, which the ECU knows is 100% duty cycle, say 8ms.

Now for the A32, it peaks at 5V around 350bhp. At 350bhp and above, it *CONTINUES* to send the ECU 5V, so the ECU keeps sending the injectors 8ms.

Now for the Z32, it peaks at 5V around 420bhp. So, from 350bhp-420bhp, the MAF voltage is less then 5V and the ECU is commanding the injectors less then 8ms of pulse width. THIS IS WHY YOU CAN'T RUN A32 INJECTORS WITH A Z32 MAF withOUT being LEAN However, with the bigger flowing injectors, you still have more fuel then the stock injectors, the MAF can still measure additional air up to 420bhp, and the ECU can extend the pulse-width back to the maximum injector pulse width of 8ms.

At this point you need a reprogrammed ECU to extended the maximum pulse width.

MAF is maxed out, so the ECU won't increase the time the injectors open. In the example above, 8ms would be the limit.

ECU.

The MAF isn't limiting his whp, he's just taking a riskier approach to controlling his air/fuel ratio with fuel pressure. He'd like to have tuning abilities with his SAFC, however that is limited by MAF max metering capability.

Redmax

iTrader: (20)

Since i am using the emanage , my base fuel is 34 psi , right now at wide open it probably goes to 42 at most, but will it truly rais eto 65 or so with hat much boost? I have no fmu. Also will I be able to get 400 hp out of my injectors? a Maf is not an issue here since the greddy pressure sensor reads 3 bar

MardiGrasMax

iTrader: (14)

You will not be able to get 400 wheel hp out of the 370cc injectors. You will need to up your fuel pressure a bit and trick the e-manage. But you still wont get 400 whp. Call me or have Adde call me and I can help you out.

PS: can I barrow your e-manage support tool cable in a few weeks to do my initial set up and tuning

IceY2K1

iTrader: (3)

Jay,

You can get a 95 or newer J30 or any Z32 MAF on www.car-parts.com for $75-$85 or even cheaper if you call around.

Here's what I've found on wiring it so far:
http://www.jimwolftechnology.com/wol...%20NISSANS.PDF

IceY2K1

iTrader: (3)

All you need is to connect the grounds, 12V, and figure out which A32 MAF wire is the 0-5V signal to the ECU.

Sounds like a piece of cake.

subs1000w

why only the 95 or news MAF i thought all the z32 and j30 mafs were the same

Julio

Now for the Z32, it peaks at 5V around 420bhp. So, from 350bhp-420bhp, the MAF voltage is less then 5V and the ECU is commanding the injectors less then 8ms of pulse width. THIS IS WHY YOU CAN'T RUN A32 INJECTORS WITH A Z32 MAF withOUT being LEAN However, with the bigger flowing injectors, you still have more fuel then the stock injectors, the MAF can still measure additional air up to 420bhp, and the ECU can extend the pulse-width back to the maximum injector pulse width of 8ms.


Not trying to be a pain, but the z32 mafs can definitely read more than 420 bhp. There are guys running 450 whp (z'ers), let alone bhp.

nismology

iTrader: (8)

Yea but aren't they running 2 MAF's? Each one is responsible of reporting only half the total incoming air so if they are used in tandem, of course the metering capabilities are gonna be more than just one MAF.

MardiGrasMax

iTrader: (14)

420bhp with 370cc injectors
520bhp with 555cc injectors

The MAF is not the issue.

subs1000w

one more piece of the puzzle solved

excelent

IceY2K1

iTrader: (3)

I thought OLDER, but typed newer.

Not sure about 96+ or when they stopped making J30s, since I-brands usually carry over a year or so past Nissans.

IceY2K1

iTrader: (3)

What jOo talk'n bout?

350bhp with 370s assuming stock fuel pressure.

Stephen Max

iTrader: (59)

~350 bhp at 80% DC. ~420 bhp at 100% DC. (Depends on bsfc).

IceY2K1

iTrader: (3)

(lbs/hr)xDC
------------- X 6
BSFC


(370/10.5)*0.8/0.6 x 6 = ~281.905bhp (80% DC)

(370/10.5)*1/0.6 x 6 = ~352.381bhp (100% DC)

What am I missing here?

Julio

I wasnt saying that the maf was the reason why the motor cant surpass the 420bhp mark. All I was saying was that this quote was incorrect:

Now for the Z32, it peaks at 5V around 420bhp

I wanted others to know that this wasnt true, and get bad info. The truth is, the maf is at about 65% of 5V at 420 bhp.

nismology

iTrader: (8)

What you say is true because the 300ZX is using 2 MAF's. If you had read my reply, you would have understood that you can't use the Z as an example.

IceY2K1

iTrader: (3)

5V was an example NOT actual.

Also, 420bhp is what JWT states, so I'd assume that's correct.

[edit]
Where do you get 65%?
[/edit]

MardiGrasMax

iTrader: (14)

Stock 300ZXTT has a single MAF. With 555cc injetors this combo is good till 520 crank HP. So the single Z32 MAF can meter 520 crank HP, but needs the 555cc injectors to keep up with the fuel demand over the stock 370cc injectors in the Z32

Sorry, Im a boost boy, so I was factoring in boost pressure, and .55 BSFC is more realistic, I guess thats about 11.5:1 AFR. option?

IceY2K1

iTrader: (3)

Yeah, but StephenMax has pointed out that the 1:1 ratio of the stock FPR is for NA, however for FI apps, you must calculate bhp based on the delta.

I agree closer to 0.55 BSFC is probably more realistic, however I've calculated 0.58 BSFC on at least one dyno and would rather be conservative.

I don't remember BSFC-to-AFR relation of the top of my head, but that sounds about right.

Stephen Max

iTrader: (59)

You're right, Icey. My mistake.

Except that I think that a Maxima engine is efficient enough that a lower bsfc than .6 lb/hr-hp can be used, for supercharged engines at least.

I dynoed at 285 hp with a duty cycle of 80-85%. That means I was making about 340 bhp. Working backwards using the 85% DC, I calculate a bsfc of .52, and that was with tuning resulting in 12.5:1 afr. A richer afr will increase bsfc, of course.

ilumo

Ok, thats good. That gives me a little more hope for my 370cc injectors handling 350 whp. So for people running aftercoolers, the BSFC could be even less correct (than .6)? because they provide cooler IAT's thus reducing the need for more fuel to cool the combustion chambers.
I have a question about the FMU though. Say you max the a32 MAF, and are at 100% DC. Depending on what ratio disk size you are using, you COULD be richening up the mixture too much when you are boosting at higher levels. Is it possible to decrease the MAF signal with the AFC even after the maf has been saturated.

Example: you are running up to 13 lbs of boost, with the 6:1 ratio disk and 370cc injectors... and at 10 lbs, the maf hits 5V from 350BHP... with the fuel pressure at 71 psi. thats fine, but then you goto 11 psi of boost, then your FP is at 77 psi @ 100% DC. thats getting to be too much, then at 12psi of boost, the FP is at 83psi, way too rich, and 13psi of boost, its at 89...

So when you maf gets saturated after 10 PSI of boost, is it still possible to modify the signal with the AFC? You should still be able to, correct? Or is there some safeguard against that? Thanks

IceY2K1

iTrader: (3)

SC vs Turbo, IC vs. non-IC, intake temps etc...

0.60 is recommended as the best "safe rule of thumb" for rich pump gas turbo'd cars, SCs are 0.55. I wouldn't ASSume anything less UNLESS I was on a dyno monitoring AFR, had wide-band such as yourself, or running J&S Safeguard.

I'm *NOT* going to put up numbers and call them "safe" for *ANY* member to assume they can run.

Every cars' operating conditions/environment will determine what BSFC/AFR it can safely and optimally run, so going with what your car or his car or whoevers car has achieved as a general guideline isn't an option IMO.

JAY25

iTrader: (38)

I highly agree with you on the conditions/envirment etc..

why do I say that. I had my car tuned for 39 degree weather/dense cold air. now the exhaust is popping because the car is running rich. Temps are in the 70's and I am now driving my turbo max as a daily driver.

Stephen Max

iTrader: (59)

You can only use the SAFC to adjust saturated maf voltage downward (resulting in leaner operation), so your fmu mo' betta being providing more than adequate fuel pressure. This is actually the safest way to use the SAFC, since it won't result in a possibly dangerously lean situation if the stops working or loses power.

HitManSE

iTrader: (1)

I must say, that is one jacked up power curve