R34 A502 and Injection adjust

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DistSynth
 

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R34 A502 and Injection adjust

Post by DistSynth »

Hi everyone.

I have a question about "Injection adjust" (not "TP Injection multiplier" aka KCONST). Does it work on my ECU or i need to reflash it with FeaturePack image?
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Re: R34 A502 and Injection adjust

Post by Matt »

It will need to be reflashed to use this new parameter. However I will be adding in the next version an 'injection divisor' which is available for NEO ECUs (which does not require feature pack)

It will allow changing the injection time (without affecting TP) from 0.5x - 8x injection so is good for rescaling from 370CC to 740CC injectors without touching K constant, and is available in the standard Nissan ECU firmware

Still use K constant to adjust for the increased measure of load when upgrading MAFs (since the main aim is not to change any TP load scales in the ECU)
DistSynth
 

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Re: R34 A502 and Injection adjust

Post by DistSynth »

Thank you for reply.
Could i use this params for changing MAF?
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Re: R34 A502 and Injection adjust

Post by Matt »

Only use it for changing injectors. Changing MAFs should still use K constant
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Re: R34 A502 and Injection adjust

Post by DistSynth »

Offtopic questions:
Now i use Nistune 1.2.23RC. So... Where now Min/Max TPulse width tables? Why Max TPulse width looks so strange?
Image
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Re: R34 A502 and Injection adjust

Post by Matt »

I found the Japanese have the TTPmin/max wrong for these engines. I've done some thorough investigation in the ECU maps and updated the software

Changes from 1.2 to 1.2.24

(a) Maps labeled TP limit/TP recover are now displayed as boost limit/boost recovery.

They are actually for the boost voltage (0 - 5.12 volts). This translates from 0 - 17 psi which is what the NEO boost sensor is capable of. More info in doc below

The ECU uses a counter which increments when the sensor voltage is over the selected table value. Once the counter reaches the 'boost counter' value the fuel is cut. Normal counter value = 10 and can be increased to 255 maximum to remove > 17psi boost cuts if increasing this table to maximum is not sufficient

(b) Maps labeled TTP min/TTP max are now displayed as TP limit/TP recovery.

If the boost sensor is diconnected, or in error, then the Theoretical Pulsewidth (TP) is used for boost cut instead of the boost sensor. Same as earlier Nissan ECUs. This was incorrectly called TTP min/TTP max which explains why TTP min had such high values

Similarly a counter is used for waiting for a specified time (10 counts) until performing the cut. 'TP counter' parameter is the max counter value before doing the cut

(c) New map identified TTP max has been added.

You will note that apart from very low RPMs, that this table is set to maximum. This is why this table (which was always never shown to the user) never needed modification. These ECUs do not have a TTP min table like the earlier ECUs. You can make the TP load value as low as 0 due to absence of these tables

Same applies for other later model ECUs (S14 240SX, A32 Maxima, Z32 300ZX 1996 etc). They just do not have the minimum TP table. I'm not sure why since it helped stablise drops in AFM voltage. Perhaps some other logic in there, or the change with how enrichment was calculated (instead of using AFM, RPM, temp based enrichment tables, we just have a VE enrichment table)

More info on NEO specific updates here:
http://nistune.com/docs/Nistune%20NEO%2 ... Tuning.pdf
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Re: R34 A502 and Injection adjust

Post by Ligouri Rd. »

Matt wrote:...However I will be adding in the next version an 'injection divisor' which is available for NEO ECUs (which does not require feature pack)

It will allow changing the injection time (without affecting TP) from 0.5x - 8x injection so is good for rescaling from 370CC to 740CC injectors without touching K constant, and is available in the standard Nissan ECU firmware

Still use K constant to adjust for the increased measure of load when upgrading MAFs (since the main aim is not to change any TP load scales in the ECU)
Any chance of seeing this injector divisor in the definition file for other ecu's using standard ECU firmware? Do you know what ecu's have this divisor (S14 non-obd2 KA24DE mabye)?
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Re: R34 A502 and Injection adjust

Post by Matt »

Only the NEO ECUs have this divisor.

Sorry nothing in the S14 KA24DE. I've kind of gone through the injection code to death on that model and it requires a 'feature pack' update for adding a 'total injection multiplier'. I've coded most of it together but the Type 4 board needs some memory opened up to fit in the new code.

Xilinx chips need updating so I will be doing exchange boards for this and providing AVP with updated boards and firmware to cover things from the USA

One I finish doing the S13 CA18DET and VL RB30/Z31 VG30 feature pack code and released it I can put the work together for the S14/B14 models

The injection adjust only has limited functionality in some ECUs.
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