TeamSwift

THE GAS PRICES ARE NOT GOING DOWN, so, I'm working on a switch that could switch between a stock chip and another (i.e. rally) in nano seconds. That means it could be done while the car is running. There would be two LEDs (green and red) for each chip and just one soft button. It would be connected to the ECU via D connector. It will take me a few weeks to test it, so during this time I would like to know should I make more of theese things, is anybody interested in this? I'll keep you posted on the progress. Suggestions?

Sounds interesting, not sure if i would bother with this myself as im very lazy, but im intrigued, how are you going to mount both chips inside the Stock ECU, is there enough space?

Prab

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Renault 25! no better dash then this!

I'm not. They'll be mounted outside of the ECU on a seperate board mounted on the ECU housing and connected via D connector. (there are a few extra elements needed for this to work so i can't fit everything inside)

This is interesting - do remember that you can get all sort of wierd glitches if you extend that parallel data bus too far - a piggy back board mounted directly off the EPROM socket with a cable to a dash mount switch, might work better than a D connector.

Parallel data bus won't be extedned too far, both chips will be on the same piggy back board connected directly to the EPROM socket with a short flat cable (~10 cm) and then to a dash mount switch with a longer cable coming from the same 37 pin D connector. Piggy back will be mounted on the bottom of the ECU with 4 screws and connected to the socket with that D connector. I hope I won't get any glitches with such a short cable... I just can't fit everything inside, the board will be as big as a pack of cigarets.

It would be nice to have a quick way to switch the chips for emission purposes .

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I was thinking cut a rectangular hole in the ECU case directly over the EPROM socket and just have the leads extended an inch or so straight up through the hole.

Something I should point out is I'm just talking off the top of my head, based on limited digital design experience, and a complete ignorance of the ECU itself.

Yes, I tought of that also. We'll see if it works without glitches this way and if not I'll have to think of something else. I'm thinking of making something that's easy to do for everyone (eaven Casey! ) and that's just drilling four holes on the top of the housing of the ECU. Cuting a hole is a different thing and I hope it'll work this way. I'll post the schematics tomorrow.

Well all you would really have to do is solder both eproms on top of each other with exception of the Chip Enable pin. And pretty much get a DPDT switch to switch between the 2 CE pins. Mind you I wouldn't use just any DPDT switch. You have to make something that would prevent any kind noise across the contacts. You could probably use a couple of resistors, a few LEDs, and a couple of transistors.. It'd be an easy circuit to design.

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"Don't argue with stupid people. They just bring you down to their level and then beat you with experience."

That's exactly what I'm doing!
There is also a possibility that I could put both programs in one chip (27C256) that would fit inside the case of the ECU but this is not a shure thing. What do you think?

I like the idea, but would the chips be programmable? In other words, would the average Joe be able to modify at least one of the maps?

You don´t need to switch between chips. Just program the other one into the unused half of the map. And then just switch the Most Significant Bit of the Address.

I recall someone did this. Maybe Garndi or someone else.

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or have the chip only affect WOT. so cruise and part throttle wouldnt have different mapping. even gas mileage wouldnt be affected.

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Ok, this is the version vith just one programmable 256k EPROM...
This could fit inside!
What do you think?

EDIT: I've removed the schematics becouse the pin layout was not correct.

not sure if I'm the only one who remembers this, but adam has dual map chips with an external switch so you can toggle between maps. I had one and I think amxdreamer had one.. not sure how many of them were floating around, but if you're really serious about wanting one, you may want to get in touch with adam. eg. [email protected]

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'92 Swift GT, '94 Swift GT, '88 Turbo Sprint, '98 Swift ... all sold years ago

I think sokre13 asked Adam about it and he said he's working on it and nothing happened after. I wouldn't have gone through all this work if I could have gotten one from someone.
I'll try this one and see how it will work.
I'm not trying to profit from this, that's why I posted the schematics...

Yes, but it only uses the upper half. I guess the only reason Suzuki started to use the 256K chip in their ECUs was because 128K ones were starting to get rare and expensive. If you look closely inside the ECU, you will see that the Address MSB (Pin 27???) is tied high (+5V).

So.. No matter the size of the chip, it will only use 128K. So you can use a 256K chip to store two chips in each of both halves. Then, get a switch, a 4.7K resistor, a couple of wire, and feed the MSB with 0-5v.

I did a short write-up on this subject a couple of years ago. Must be somewhere over the forum.

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A company called Fueltronics here has been doing this since the very early 90's.

So why have this? You will really only have one program there that actually suits the engine, i.e. a stocker with a big limit will go slower as the power dies in the bum at the higher rpm, or a modified car will idle like crap with the tables changed to attempt some economy. I think this is why that product was dropped from their line.

However, ONE better use for it is to have a lowered revlimit, say when you send your car in for servicing....or when you park it, for security. Great idea for other uses...but for actually continually running the engine I don't think it's that super. But hell, it's only my thoughts, so go for it!

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Don't ask me, I don't know anything. And just because I'm a senior member, it does not mean I have as many wrinkles as ellpee. 1500+ posts and still I haven't got a clue.

Well that's this lower schematics... Those are not two chips there, one is a socket. I had to make it like that so it would fit inside the ECU case. What I said was: This is the version with only one chip that will have both programms. ECU will use the half I choose. What do you think? Is the schematics ok? I'll make the board next week.


This schematics is done like this so it resets each time you turn off the ignition, this means the car will allways start with the rally program (in my case)
I noticed an increase in fuel consumption eaven on easy drives on the longer trips and gas over here costs like hell! (5,5 $US / gallon)
I need an option of lowered rev limit, when you send your car in for service....or when you park it, for security as you said. One other interesting thing is emission. It's really a pain in the a$$ taking that ECU out any the time you need a stock chip.

Oh, I see now. Looks good !

How about deleting the 74HC14 while keeping the debouncing 10nF cap ?. You can also delete the 2 transistors, as a the CMOS outputs Q and /Q can drive both LEDs (25ma source/sink current while a LED typically operates at 10mA). Another option is to make a bistable from a 556.

So, you delete 2 transistors and 1 integrated circuit, making it smaller. I like the Idea of the power-on reset.

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74HC14 is here just to avoid contact voltage peaks and theese two transistors to avoid the overload of SN74HC74, it needs to be very stable becouse of a car use. I can't risk anything here, the board is made this way so it could fit inside so there's no space issues. It could work via 556 but I just did it this way... I'll try to make the board this week...

Yes, I know. Quite overkill, but works either way.

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I have to wait for the board another 10 days...

What ? You don't make them yourself ? I have a good trick to transfer the circuit from a Laser Print or a photocopy to the board, you just need an Iron, water, and, of course ferric chloride. No expensive photochemicals.

http://www.pablin.com.ar/electron/truco ... /index.htm

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Megasquirt tutorial --- http://caaarlo.50megs.com

Yeah, I did it in school only with stickers and it wouldn't turn out so great and it couldn't be so small. But this is an interesting idea with the iron...
Tell me more, please. The only thing is that this is a double layer board. I'll do this first two at that shop and test them in my and sokre13's car to see how it goes...