Nissan ECU Tuning

zmanphx2000 · Joined: 10 Dec 2003 Posts: 4 Location: Phoenix Arizona

I've been doing a lot reading on Devins site and studying how the ecu maps all works.
I noticed there are only 16 load points per rpm point. I know a lot of stand alones have up to 32 load points.

The problem I see has to do when the map is expanded for 2 bar or maybe 30 psi of boost. That means the resolution per load point will be lower. A hypthetical example , 18psi will get the same fuel as 20 psi of boost because load point has to accomadate an wider boost rainge.

Is this what happens when you expand the map for higher boost?
Thanks,
Mike

RomChip200 · Joined: 27 Nov 2003 Posts: 196 Location: France

I think the Nissan engineers use 75% of the 16 load points for the range
-0.9 ... 0 bar because it's the range where you are most of the time.
Pollution, ecology reasons also.

And I suppose over 0.3 bar for example, the injector pulse stays the same whatever the airflow pressure is (till 1 bar for exmaple). It's the FPR which does the job, it is more and more closed with the pressure increasing and then, the amount of fuel increases even if the injector pulse stays the same.
I speak about a stock car though.

When the time for bigger injectors come, you have to play with this.
_________________
200SX CA18DET S13 '92.
300ZX TT '91.

Ryan · Joined: 24 Nov 2003 Posts: 86

Hi,

Don't forget that theese are correction maps, the motor will get more gas at 20 psi because the airflow sensor will see more air , and a longer pulse width will result(untill max pulse width), it will only add the % more to the pulse width from the last point on the map.

Cheers
Ryan