Nistune Forums

Is the K-value is only read once when the ECU boots up after turning the key or if it is reread during running?
Or in other words, is the k-value read once into a scratch ram area and all codes only reference them here or does every code portion always reads this value for calculations from the eprom again?

reads each injection calc cycle

Thanks Matt

Hi Matt
Will a stock nissan firmware reread this value everytime too, or is this a special feature from the Nistune firmware addons?

Keeping in mind that you have modified the code for a consult implementation over USB this might be a function which has to be implemented for realtime tuning and is not typically part of the nissan code.

But i must know if a stock nissan eprom code would change the pulsewidth when the k-value would be changed on the fly.

To be more concrete. The car has 440 injectors running and a Z32 AFM in a Stage3 Setup.

But a conversion to LPG gas fails because these gas injectors are maxed out.
So the plan is with a switchable Eprom to return to a 370ccm Z32 AFM version - for this size of fuel injectors a gas equivalent injector exists.

Here the k-value is changed on the fly and also the correcting boost tables.
If both, the scale and also the k-value would be read from the eprom in all situations this would be a possible solution.

It's obviously clear that LPG is only for travelling and low load situations ( 99%) with reduced boost.
and for full load the switch goes back to fuel with maxboost and 440 injectors - a two stage turboxs boost controller is handled accordingy at the same time.

kind regards

we did not modify anything apart from adding a communications mechanism to the existing ROM code

so for stock firmware for injection is the same

Was wondering what the limitations are of gas injectors. Some people on forums have talked about using two per cylinder to get the required amount of gas in

you should be able to switch between two banks of an EPROM are you indicate having a LPG mode and a petrol mode.

That is a very good idea, because you can boost in petrol mode and then run stock / low boost in LPG mode with the smaller injector size

Hi Matt,

Injector flow and calibrator availability are bottlenecks for high-power applications.
Two injectors is a possibility but it is an expensive one.
For the material sold here, it seems that 440cc fuel injectors can not be replaced by a single gas injector. For the stock injectors of 370cc (CA18DET) it should be possible and one of my friends is seriously considering such installation.
I'll let you know how it goes.
Kind regards

We've been doing map switching on our EPROM boards for S13 SR20 for awhile now. 1MB EPROM allows you to program 4 complete images. You can switch between the images while the car is running no problem.

I'd stopped making the 4 map switching modules (although the EPROM boards by default will still take 4 maps). But now with the advent of E10 and E85 fuels there would be distinct advantages to be able to switch to a different tune for the different fuels, so I might start making them again!

CA18 is even simpler - just toggle the high order address line with a toggle switch for 2 maps.

PL