Eprom switch project

[Gery83]

I had the idea, why can't I use my car normally with factory consumption, and some days with a tuned chip. So how to make this without removing the eprom each time?

I made myself a simple eprom switch. This board you can place in the ecu, and with the ENGINE NOT RUNNINGyou can easily switch between two eproms.

I have not tested it yet, because my engine is right now in many pieces...
But it works this way:
The two eproms are connected parallelly, except the Output Enable (OE) pin. With the switch you can choose between this pin of chip1 or chip2.
We also need 2 pull-up resistors with 22k value.
And theoritically thats all.

Here are some pictures:

To fix the board, you need to drill three holes, as marked on this picture:
100_3655.JPG

100_3662.JPG

100_3665.JPG

A picture of the Layout editor:
board.jpg

The PDF file of the board:
eprom_switch.pdf

[jimnielsen]

Thats totally cool Gery - I love to see hardware projects! You can also accomplish a similar thing with the Moates ostrich 2.0 - and after you plug it in you can switch eprom code very easily.. it even supports bluetooth.

jimn~

[MaxiBoost]

nice job ,
you can switch it when idle !

I was make and before use too (quadro chip !)

[Gery83]

nice job ,
you can switch it when idle !

I was make and before use too (quadro chip !)

Really?
I probably haven't tried it, if you don't say so.

Thanks!

[arjunior45]

You can switch at idle as far as you have not altered the maps data that concern idle. Who does such a job?

I use a 4 maps eprom switch with a 27c1001 eprom and switching from one to another at idle gave me no problems at all.

In a friend of mine we use the same 4-maps eprom switch and he switch from one map to the other even at high revs. Only that all the maps are quite similar.

Have faith in Maxiboost, you can switch even at idle.

Nick

[Gery83]

You can switch at idle as far as you have not altered the maps data that concern idle. Who does such a job?

I use a 4 maps eprom switch with a 27c1001 eprom and switching from one to another at idle gave me no problems at all.

In a friend of mine we use the same 4-maps eprom switch and he switch from one map to the other even at high revs. Only that all the maps are quite similar.

Have faith in Maxiboost, you can switch even at idle.

Nick

Thanks guys!

[Brul(tm)]

You can switch at idle as far as you have not altered the maps data that concern idle. Who does such a job?

I use a combi prom from Squarda. Unfortunatly the are no longer available I have 4 maps. I should have some information in the mail somewhere with information about thirt party switch solutions. Must look in to this if required.

About the switching, this can be done at idle or when accelerating with running engine. No problem at all with the solution from Squadra.
Never change to a different map when deaccelerating, you will get fuel cuts and other strange reactions from the engine.

Greetings,
Marc

[Juan AR155Q4]

You can switch at idle as far as you have not altered the maps data that concern idle. Who does such a job?

I use a 4 maps eprom switch with a 27c1001 eprom and switching from one to another at idle gave me no problems at all.

In a friend of mine we use the same 4-maps eprom switch and he switch from one map to the other even at high revs. Only that all the maps are quite similar.

Have faith in Maxiboost, you can switch even at idle.

Nick

Nick,
Is the eprom switch a DIY?
Have you got any schematic of it?

[arjunior45]

Nick,
Is the eprom switch a DIY?
Have you got any schematic of it?

yes, it is a diy, based on a Japanese friend project. Sory, I have not the exact pcb schematic as I was forced to change the position of the switch pins {move it to the side as for the 2 maps switch in the photo} in order to avoid contact with ecu walls.

Hope the followings attachments to help you.

[Juan AR155Q4]

Great Nick!!!
You ?re a big source of info!!!

One question, I don?t understand the first position. This means that without conecting pin 1 to any other it?ll set the 1 map?

[arjunior45]

Great Nick!!!
You ?re a big source of info!!!

One question, I don?t understand the first position. This means that without conecting pin 1 to any other it?ll set the 1 map?

Yes, with 1st position {not connected to the other two pin you read {if I remember well} the bottom of the bin.
If you make this 'switch' write a 1001 eprom and read it afterwards. You will see the exact location of the maps in the bin making the various connections. Sorry, I do not remember them exactly and after a HDD crash I lost lot of infos - notes.

Need to read one of the 1001 eprom I have to tell you the locations but I can not do it right now.

Nick

[WhizzMan]

Switching EPROMs without digital "dampers" like this DIY is tricky because the ECU will see no or different chips a few hundred times in about 1/10th of a second while switching. The more elaborate solutions use some extra electronics to make the switch in 1 go. The simple DIY solution works fine with the ignition off, but for switch-while-running I'd recommend the kits that have damping.

[Borbetier]

Well, old thread, but is there any 4-Switch available for sale yet?
Or is this DIY Solution that good working, you don´t need one to buy and do it all yourself? Any improvements regarding the damping?

Not only Alfas do have the 27C256 in their ECU ;-)

Regards from Germany
B.

[Borbetier]

BTW: I´ve contacted squadra and they said

"Yes we made those a long time ago. We don't make them anymore. Also all components and layerboards are gone. Sorry."

Now, as I am no electrical engineer, I barely understand the scheme:

The inner "lines of circles" are the chip, the outer lines is the socket, Connections, Resistors and Capacitor are all clear, but what kind of switch is used and how does this switch work?

The "2Timer" from moates has one (1) wire coming out and a switch for "connected to mass / not connected to mass"...