Has anybody heard of a mod where you put in a second ECU into your car, with a simple switch that controls them - chip one has minimal performance, but your fuel economy is something special, but chip two is max performance, wringing out every single last percentage point of a BHP, regardless of what the fuel consumption is?

Have I just made that up, or does it exist, can it be done, is it practical, is it safe, and who would be good to ask?

Have heard of custom engine management systems that can do this, but not any more than overhearing bits of info, not any rock solid stuff unfortunately

Pity, really - I kinda liked the idea of having a flashing button marked "Pursuit Mode", like they did on Knight Rider (man, the 80's rocked!).

MagnaMorbius said:

Pity, really - I kinda liked the idea of having a flashing button marked "Pursuit Mode", like they did on Knight Rider (man, the 80's rocked!).

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To go this far you would need a bit more than a switch and an ECU.

There are a number of manufacturers who make ECUs with more than one setting. The idea is more for racing applications than anything else.

For road use they are only any good when having forced induction because on n/a cars the difference would be far to small to justify the finacial outlay..

NOS switch?

Helz said:

NOS switch?

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Much better idea.

This was very easily done on the Punto GT's. They worked on the 27C256 eprom and all you had to do was to use the 27C512 instead, with the two bin files, the standard and the upgraded one saved at the same file. Switching was easily done with a switch connected at the A15 pin of the chip, which controlled the most significant address bit, changing addressing from 0-256 to 256-512.

Pity our centos use the 27C512 and there isn't a 1024mbit pin compatible eprom, to perform the same trick...

But its not like you could flick the switch while you were driving it right ?. surely you would have had to reset the ECU, by either turning off the ignition or disconnecting the battery for this to work ?. And how would the engine cope with looking at a new map, but still the same learned tuning parameters ?

Owen.

stylers said:

But its not like you could flick the switch while you were driving it right ?. surely you would have had to reset the ECU, by either turning off the ignition or disconnecting the battery for this to work ?. And how would the engine cope with looking at a new map, but still the same learned tuning parameters ?

Owen.

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ECU switches on and off pins A0-A14 when it needs to access various memory addresses. We do the same thing with pin A15, so we don't need to turn power off. Switching is instant too, because it happens within the eprom itself.

I have manufactured a PCB that can host two 27C512 and select one by the CE (Chip Enable) pin#20. Should be fast enough too, to switch while running, but didn't find the time to check it thought...



Learning of the ECU depends on the condition of the engine and whether the chip is car specific or not. And i don't think that 10 or 15 miles of learning is that much of a trouble, unless you intent to switch back'n'forth everytime you leave the city and enter a motorway and vice versa...

What about if it's because there's an irritating cretin in a VTS who I see, every day, on the way home, and insists on ragging his car to death beside me? I can't be bothered racing him (1.6 vs. 1.2), but just once I'd like to flick a switch, sit next to the smug little sod, and then burn off into the sunset...

ok, i just thought that the processor might hang if the EEPROM was addressed like that. but if it works, it works.. cool. I think there might be switching time issues with swapping between two EEPROMS for the 27c512's too.. thats a nice little PCB btw..

Owen