Twin selectable ECU maps???

[George_Of_The_Jungle]

Hey guys, wanting your thoughts on an idea.

the basics of what i want - a stage switch.....

I'm thinking about having a switch that switches between, a number of maps. Economy map, FIRE-BREATHING map

is it possible?

Piggy back chips?

i dont know?

any ideas?

[e21Jason]

It's a standard feature on most aftermarket ecu's inc the piggyback ones, what's your budget.

Jason

[Speedtouch]

I have seen this done, by Yanks, eg http://forums.pelicanparts.com/showthread.php?t=421262

You can use a larger EPROM (512 instead of 256 type) which can then be programmed with two maps selectable by a toggle switch.

[Turbo-Brown]

In my mind, there is only one map.....and that the correct one!

You could have different maps for different fuels perhaps, or I was talking to a guy the other day about having his meth injection rigged up to a map switch so when it runs out the map changes to one that doesn't rely on the meth.

On a turbocharged engine you could change the boost charactaristics (if you've mapped your boost that is)

But if you're having your engine mapped, your mapper should be looking for maximum power at full throttle, and half decent economy elsewhere. Power and economy are not mutually exclusive (thankfully!)

[George_Of_The_Jungle]

what's your budget

what ever i can make my self...

or a small number of pennies.....

I dont want to.... well i would like a stand-alone ECU, but not gonna happen. just looking for a reliable way of having parallel chips, then a switch that closes the loop to one or the other.

how many outputs come from the chip? the inuts wouldnt need to be switched? just the outputs?

[e21Jason]

Remount your ecu so it is easy to get at and swap it over between chips woudl be the easy way.

Build and MS set-up and get even more benefits. What would the map differnce be target AFR's

Jason

[George_Of_The_Jungle]

AFR's

???

[e30_Turbo]

MS can do different maps and emerald can swap using a toggle switch.

I'm totally with Alex on my views re maps and mapping.

One map has so much scope to cover all driving conditions, for one fuel tho, so I guess with a little race fuel up it you'd want to make some changes or maybe a flame thrower map for setting the car behind on fire, if that's your thing.

I bought and built my MS V3 for less than £200 so it can be done on a budget.

AFR, Air Fuel Ratio - most ecu's will cross ref AFRS against actual using a WB and make adjustments accordingly, how fast and how much are set by the user.

HTH, Fozz.

[FlappySocks]

As what others have said, one map. You only really need to switch if your switching fuels (like to LPG). If your on a budget, and you want to do it all yourself, then MS is the way to go. You can have your fire-breathing mode, just my stamping on the accelerator pedal. MS knows when your in a hurry! The choice between modifying a 20 year old EFI system and MS with all the extra benefits that it brings is a no brainier, and not expensive.

[George_Of_The_Jungle]

what sort of power figures do you get with MS?

[march109]

what sort of power figures do you get with MS?

Same as you get withought unless the previous map was way out and the engine has more to give.

[Speedtouch]

Another option is to solder in a 'breakout box' into the Motronic ECU's EPROM socket and lead this out to either a ZIF (Zero Insertion Force) quick-release socket for easy chip changes or like you say a board with two EPROMs with their inputs wired in parallel and a toggle switch to select which chip's outputs are used. It wouldn't cost too much - some Veroboard (or a PCB if you're feeling flush), ribbon cable, a switch, a couple of EPROM sockets and odds & sods.

[George_Of_The_Jungle]

In my mind, there is only one map.....and that the correct one!

You could have different maps for different fuels perhaps, or I was talking to a guy the other day about having his meth injection rigged up to a map switch so when it runs out the map changes to one that doesn't rely on the meth.

On a turbocharged engine you could change the boost charactaristics (if you've mapped your boost that is)

But if you're having your engine mapped, your mapper should be looking for maximum power at full throttle, and half decent economy elsewhere. Power and economy are not mutually exclusive (thankfully!)

thinking about it this is going to be the best method, have it properly re-mapped. a map that produces 'mucho' torque throughout the rev range is going to be powerful, and economical when driven non-enthusiastically
still going to cost top dolla though isnt it.
any way thanks for all your thoughts

[EndaW]

This is simple.
You use a 27c512 and write map one to the higher side of the chip and map two to the lower side.
You run a wire from pin2 of the chip to switch from h/l.
Upper bytes start 0000f in the source.

[Ant]

or, double easy.

open the ECU and drop a ZIF socket on the PCB, mod the upper case and swop as and when.

what Enda has proposed is spot on, indeed the 073/071 is a page file setup as std, hence the fuel quality switch.

using a 512kb chip and twin maps would mean you can swop on the fly though, unlike the ZIF proposal

iirc, Tandy used to do a twin eprom PCB kit for just such a purpose.

[EndaW]

My god, are there any tandy stores around these days ? ive not even heard the word tandy since I was a kid and yes, as you said, they used to sell twin boards, even in plcc format 32 and 44.
Maplins come along as far as I know but tandy was like the spectrum 48k of the electrics stores

[Ant]

must confess, I've not seen a Tandy for at least 5 years or more.

Dammit, getting old !

[EndaW]

There used to be one in my town, it was the only place to get rechargable batteries, I remmember when having rechargable batteries was like having a tv with a remote controller and no wire.

[Speedtouch]

Presumably, you'd need to run in the program each time you switched over, so the car would run rough for a while?

[Ant]

on the 173 style ECU there is no ram as such, the rom is used as ram so once the toggle is made the file should swop straight accross.

you could do this on the 073 series too, if you jumpered the on board 8k ram out of the loop

fyi I checked with radio shack online and the twin eprom PCB kit they used to make is NLA, what happened to electronics as a hobby ?

Re the MS, no AFM is a major bonus, imagine spending £££ on remaps with a 20 year old mechanical device as the main metering device ( shudder ) Obv a new AFM is very low on anyones list of must haves.

you could also switch between two maps without a toggle.

example.....

MS has two fuel and ign maps, plus two closed loop look up tables ( one for each map set ) + CLT and IAT based trim maps, plus provision for mapped boost tables x 2

you set the MS to switch from one to the other @ a given throttle opening, say 70% so lean cruise map with loads of timing below 70% then after 70% the second maps would be employed, this would give 12x12 X 2 and great resoloution for mapping with.

That said, a "cane it map" + wideband and some closed loop lean cruising look up tables @ low throttle opening would achieve the same result