R32 GTR 1000cc Injector Data Help

[BourneToLive]

Good morning, gents, 

I recently bought and installed the Bosch EV14 1000cc injectors from NZEFI and it included a paper with injector data for tuning, but the nearest tuner is nearly three hours away, and I just need the car to drive normally until I can make time for the trip. I will attach the picture. I have ap Power FC and was wondering if it was possible to input any data through the FC controller to improve its performance, for the time being. 

[Murray_Calavera]

What injectors did you have before you installed the EV14's?

[BourneToLive]

On 8/8/2021 at 4:10 PM, Murray_Calavera said:

What injectors did you have before you installed the EV14's?

I had the Nismo 555cc injectors. The injector data on my PFC showed 82% at 0.06ms.  
 

 

 

 

Edited August 8, 2021 by BourneToLive

[BourneToLive]

I meant 0.08ms. These are my settings. 

[Murray_Calavera]

Before you start changing anything, do you have a wideband o2 gauge installed? 

Are you just trying to safely limp the car to the tuner or are you planning to drive the car around normally and eventually take the car to the tuner? 

[BourneToLive]

On 8/8/2021 at 9:46 PM, Murray_Calavera said:

Before you start changing anything, do you have a wideband o2 gauge installed? 

Are you just trying to safely limp the car to the tuner or are you planning to drive the car around normally and eventually take the car to the tuner? 

I don’t have a wideband. 
I intend on driving it normally until I get it to the tuner in a few days. As of now, it idles fine and cruises fine. I just don’t want to risk breaking anything. 

[Murray_Calavera]

You wont know if your at risk of breaking anything without a wideband. You'd be surprised how far out a tune can be and still feel fine while driving around.

[GTSBoy]

On 8/8/2021 at 10:34 PM, BourneToLive said:

I intend on driving it normally

If that means <2500rpm and no load at all, then you could get away with it. Still not a great idea.

[BourneToLive]

I took my car to a tuner today and he said the injectors are too big for the PowerFC to handle. Told me to get a better ECU. 

[Kinkstaah]

This, while disappointing isn't entirely inaccurate.

There's only so accurate you can get when you have larger injectors and a certain 'step' you have to use to drive them. The minimum adjustment the powerFC can make results in it being too rich on one setting, and too lean on the other.

Newer ECU's allow for finer 'steps' which means these can be dialled in more.

That said, you'd think the tuner would at least be able to get it running with the whole '1 step too rich' being the norm. Especially after a 3 hour drive..

[BK]

On 19/08/2021 at 7:21 PM, BourneToLive said:

I took my car to a tuner today and he said the injectors are too big for the PowerFC to handle. Told me to get a better ECU. 

Complete bullshit, power fc handles them fine 

[joshuaho96]

Isn't the whole point of any standalone ECU to be able to put in injector characterization data and just have everything work unlike a Nissan ECU where prior to Nistune FP you had change MAF + injector together to keep load scales roughly in the right place? Searching around online it looks pretty simple to change injector settings while keeping the rest of the map the same, just write down the old settings for injector flow/latency before you start changing things.

[GTSBoy]

The problem with older/cruder standalones is not that you can't set the ECU to know what their flow data is, it is that they struggle to control the injectors to really short pulsewidths, which is what is required to idle (and possibly even light cruise/trasnsient) on very big injectors.

The PowerFC is old and crude. So it's not ideal for large injectors. But the evidence does show that plenty of people have successfully run ~1000cc injectors on FCs. They just probably have fat idle mixtures (because the alternative is lean idle, which is terrible).

[BourneToLive]

The tuner I took my car to is famous in Japan, and I assume he doesn’t want to taint his reputation by cutting corners and doing a risky tune. From just installing the injectors and without making changes, the car was able to start and idled better than most eco cars that tremble like crazy. It cruises fine, but runs very rich. I can tell from the popcorn in the rear from just lightly letting off the gas pedal and the smell (no leaks). I was able to drive it for a six hour round trip without any issue, other than what seemed like misfires at fifth gear below 2500rpm. This is my daily at the moment, and I know it’s risky to drive it without a tune, but four of my six cylinders were running very lean and two of them were very rich with the old injectors. I can’t extract my current map and send it to a tuner either because I don’t have a Hako or Datalogit to do so. Unless someone has one they want to sell. 

[GTSBoy]

If it was tuned by someone who knows what they're doing, it wouldn't have to be a risky tune. It would just (probably) be too rich at very low loads & idle.

 

[BK]

Of course it's rich if it was set to 550cc injectors and you threw 1000cc in there without changes... it's injecting at least 35% more fuel than it should be everywhere !

The way it works is your power fc is factory calibrated to the standard factory injectors, so GTR 440cc low impedance injectors by default. The method to change to 550cc is 440/550 = 0.8 or 80%, hence why your injector settings were at 82%.

On 08/08/2021 at 8:59 PM, BourneToLive said:

To set your injectors for the 1000cc ones is the same. As your data says they are 906cc at 3bar, it is 440cc/906cc = 0.4856, so you set your injectors to 48.5 - 49% - job done. If your tune was any good in the first place it will be a least 95%+ the same.

Also to note as the factory fitted injectors are low impedance as are the Nismos, so you need to delete the injector resistor ballast to run high impedance injectors. They are Bosch units they supply and should have come with one of these which I hope you are using:

[BourneToLive]

On 8/20/2021 at 9:00 PM, BK said:

Of course it's rich if it was set to 550cc injectors and you threw 1000cc in there without changes... it's injecting at least 35% more fuel than it should be everywhere !

The way it works is your power fc is factory calibrated to the standard factory injectors, so GTR 440cc low impedance injectors by default. The method to change to 550cc is 440/550 = 0.8 or 80%, hence why your injector settings were at 82%.

To set your injectors for the 1000cc ones is the same. As your data says they are 906cc at 3bar, it is 440cc/906cc = 0.4856, so you set your injectors to 48.5 - 49% - job done. If your tune was any good in the first place it will be a least 95%+ the same.

Also to note as the factory fitted injectors are low impedance as are the Nismos, so you need to delete the injector resistor ballast to run high impedance injectors. They are Bosch units they supply and should have come with one of these which I hope you are using:

I had already installed the ballast delete with the injectors. And I did research on the changes to Injector duty to compensate for the bigger injectors yesterday and gave it a shot. I set it to 52.1% at 0.06 and it stalled out any time I came to a stop, so I set it to 74.1% instead and it fixed that issue. Although, since my last tuner tuned the ECU to work with the 555cc injectors, I based my calculations on the previous injectors and came to ~64%. 48% turns the car and then shuts off immediately. 

Edited August 20, 2021 by BourneToLive
Typo

[BourneToLive]

I just tried 64.1% and it started and idled fine, except the RPMs seemed to fluctuate a bit more (between ~30rpms) than when it was to 74.2%, where it maintained a pretty consistent idle and stayed within ~10rpms. 

[GTSBoy]

On 8/20/2021 at 10:24 PM, BourneToLive said:

48% turns the car and then shuts off immediately. 

That would likely be a dead time issue and also related to the very short pulse widths required to idle it. The short pulse width will be badly affected by the dead time. Effectively you need "less scaling" at the low end (effectively giving you the ~75% that's working for you) and "more scaling" (which is actually "correct scaling") at larger loads.

I know this sounds like it contradicts what my first post said, but it doesn't really. The problem of older slower ECUs managing short pulsewidths is still a thing.

[BourneToLive]

I assume that can’t be adjusted without accessing the current map with an FC Hako or Datalogit, correct? 
 

Are the digits on the right (+0.06) the dead time? 
I calculated:

1000cc injectors -> 0.989 @ 14V

555cc injectors -> 0.6

0.989-0.6= 0.389 dead time

Or at least the nearest value I can get it to. 
 

and the injectors (based on last tune):

555/906= 0.612 or 61.2%

Is this correct? 

 

 

Edited August 20, 2021 by BourneToLive