Page 19 in the ecu tuning manual It begins to show you how to get your afr in the ball par of 14.5:1 and I just want to make sure Im understanding this right:
1) vehicle gets up to operating temp
2) zero out or the letter "O" out the lighted cells
3) cut of the O2 sensor in flags
4) Adjust the k constant while to cruise partial throttle up to 3,000 rpms
During this time are you adding and subtacting in the cells that are richer than 14.5:1 or leaner or just adjusting the k constant?
5) It says that the cells that where "Zeroed" need to be set back to the stock value:
What exactly does that mean? Highlight all the highlighed areas and press "zero" or the letter "O"? What was the stock value before?
If im reading it correct you zero everything, cruise and make adjustments accodingly, when done just hit "O" for all the highlighted cells for low throtle and tune the O2 sensor back on...And then after that you can tune the un-highlighted cells(more so boost) with the O sensor on...
Trying to figure out this k constant thing....?
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Nissanclubman
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Re: Trying to figure out this k constant thing....?
Hi Mate, I see you haven't had any feedback so thought I'd chip in some comments.
I haven't gone to check out the manual however the AFR 14.7 and K constant adjustment are only loosely related.
The Nissan ECU has heaps of different adjustments that keep the motor in tune during warmup and when up to temperature. Fundamentally if all of these are stripped out the ECU has a fundamental tuning design based around 14.7.
The K constant is a bit like a set point control that adjusts that underlying base tune so you can manage fundamental changes affecting that base tune like Injector sizes, MAF meter changes etc These thing affect the whole tune of the ECU eg If you increase your injector size by 50% then you need to reduce the K constant by the same % otherwise your whole tune will be out by that amount. Tuning the MAP cells is the place to go once you have the K constant correct then, generally speaking, you don't change it again..
If however non of the core engine parts are changed then you probability won't alter the K constant from the factory setting, you would go to the fuel map and tune the particular cells for the AFR you're chasing.
A big NOTE however is you need a Wide Band O2 monitor to do your tuning not the std narrow band that comes with you car. Also be aware there is a lot of other things that affect idle, WOT performance and general drive ability that may need the AFR to be richer that 14.7.
Hope this helps. Cheers for now Richard
I haven't gone to check out the manual however the AFR 14.7 and K constant adjustment are only loosely related.
The Nissan ECU has heaps of different adjustments that keep the motor in tune during warmup and when up to temperature. Fundamentally if all of these are stripped out the ECU has a fundamental tuning design based around 14.7.
The K constant is a bit like a set point control that adjusts that underlying base tune so you can manage fundamental changes affecting that base tune like Injector sizes, MAF meter changes etc These thing affect the whole tune of the ECU eg If you increase your injector size by 50% then you need to reduce the K constant by the same % otherwise your whole tune will be out by that amount. Tuning the MAP cells is the place to go once you have the K constant correct then, generally speaking, you don't change it again..
If however non of the core engine parts are changed then you probability won't alter the K constant from the factory setting, you would go to the fuel map and tune the particular cells for the AFR you're chasing.
A big NOTE however is you need a Wide Band O2 monitor to do your tuning not the std narrow band that comes with you car. Also be aware there is a lot of other things that affect idle, WOT performance and general drive ability that may need the AFR to be richer that 14.7.
Hope this helps. Cheers for now Richard