Possible solution to 1uz-speed issues.

[NavySupra]

I'm talking to an automotive software engineer in the states who might be able to build me a piggyback unit that would plug into the lexus ECU. from what I can tell I might be able to split off the speedo cable and have one go to the dash, and another to a nissan speed sensor, say from a GLL 300zx. This would report to his piggy back unit, and it would interpret the data in the most efficive manor.

My theory on it is that when the clutch is depressed the piggyback will report to the ECU that the auto is changing gears. I would find the best power curve, which is probibly second, and some how cause the piggy back to keep the ecu thinking that its in second, or whatever. Ebrake, clutch would act as park/nuetral kill.

I'm not 100% on how its going to work yet, we're still going over the wiring diagrams and trying to establish everthing that the ECU needs. Though this is a project I'm working on.

-Shane

 

[Lambo]

Tricking the ecu

Hi Navysupra,

I too have been investigating this problem, i suspect the kickdown switch may also tell the ECU to retard or advance the spark at the moment of changing gears, and then the ECU reads the transmission speeds, and road speed, and revs to decide what gear to select, or maybe the Auto works like an ordinary gearbox and senses hydraulic pressure, don't know if this is the case anybody out there know?.

Best regards
Lambo

 

[Miles B]

Why don't you ask Harry on ALSC, who has decompiled the code in the ECU, if the gear maps are any different? I believe they aren't. I'm just going to tell mine the shifter is permanently in "1". Apart from that, when I get boost I'm going to hand control over to an Autronic SMC anyway. Why leave it in the hands of the stock unit with piggybacks which would probably cost as much as the Autronic.. which knows boost and you can fiddle with the maps 100%