<span class="highlight">Performance</span> <span class="highlight">Chip</span> - 4.8 Patrol

The same question was asked over at the Patrol forum

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Hi Peter

Some issues arose when I fited a unichip to mine and while I have dyno reports that show it put out about 12% more power , I very carefully tried to verify this and was unable to show that there was any improvement.

Issues are that these things work by advancing the static timing
then cutting this back and also changing the injection pulse width.
They only work on open loop.

The people who supply and fit Uni-chips seemed to have little knowledge of how these things really work and set my car up in such a way that it stalled off idle.

I seperately determined that my patrol could not have its static advance moved forward my more than 6 degrees else the ECU would not work properly, after this I set the advance and let them re-tune it from there as best they could.

Mine is a manual and if you have an auto this defect may not be apparant - but check it first yourself.

There are other things to be aware of if you get more serious , but one thing you should do is have some means of accurately determining your cars performance like an acceleromter so that you can see independantly if any installation works.

Seperately to the above I made a microcontroller to overide the oxgen sensor and deliver better economy, this works on closed loop but is not for the faint hearted as it can drive the ecu into a lean error mode.

Over its long life my 4800 has delivered a liveable 16.5 lt/100km
and just last night we got back from a bike ride of Simpson in which my car was driven by someone relatively in-experienced as a support vehicle towing a bike trailer and looks like it achieved a great 24lt-25lt /100km thru the crossing.

(if anyone tells my wife about this reply - there in big trouble)