Launch control for Motronic

[S2central.net]

Working on the analog adjustment today - will require some ecu mods and link cable to an external pot.

[Dan]

This thread makes me want to learn more about Motronic.

[Zoig]

Working on the analog adjustment today - will require some ecu mods and link cable to an external pot.

Is there a possibility that it could be adjusted via the adjustable intermittent wiper button on A4 B5 stalk?

Looks similiar to B4/C4 stalk, so it might be possible to install this to B4/C4 cars.

[prj]

Too much work.
But if you want to do it for yourself - it's likely you can.
The ECU expects a 0-5V input, that's pretty much all that there is to it.
Anything you can install that generates voltage in that range will work.

[Zoig]

Then it should work. According to B5 schematic the wiper intermittent control is via rheostat.



Edit, I just like OEM looking solutions

[S2central.net]

I also want to do this in a way that is compatible with the plans for flat foot shifting - or FFS to its friends This requires another little component to keep things safe in a corner case of operation. Me being me will want this to be something that can be cleanly installed with proper connectors and such.

There are all sorts of ideas for where the actual control pot would be placed. Watch this space on that one as there are other ideas brewing in my head for extending the capability of the mighty Motronic ECU and how to make it easier to connect to the outside world - I would like to build a prototype first... probably needs a simple PCB to be made though - ahh fun.

[S2central.net]

Figured the best way to garner opinions from those interested in a launch control option - with a subtle control knob that sets the rev limiter - was to do add a poll to this thread.

My personal preference is down near the diff switch area as there is good room in that area and its easily tweaked when the occasion arises.

A knob in the upper console switches or steering shroud is a bit less subtle and is more fiddly for installation...

Use of the wiper stalk knob is interesting but adds to the cost considerably and of course the pot would need to be the right range.

I am quite sure nobody wants new holes in their dashboard either - though thats up to them if they wish.

[Billman]

I have a question here! Is it possible to play with such a potentiometer and can trim injector PW, boost and advance?

Advance +- 10 degrees
Boost +- 0.7 bar
Injector PW +- 10 MS or so.

Something like this would be great!

[prj]

I have a question here! Is it possible to play with such a potentiometer and can trim injector PW, boost and advance?

Advance +- 10 degrees
Boost +- 0.7 bar
Injector PW +- 10 MS or so.

Something like this would be great!

In theory - yes.
In practice, if you want to do that, you just buy an emulator.

[Jonas_R]

How about making it so it could be change via VagCom? That would be nice

[prj]

How about making it so it could be change via VagCom? That would be nice

The launch control? I think the potentiometer is a better idea - because if your ecu loses power you will lose LC settings as well.

[Billman]

what if i dont want an emulator?
034 Motorsport said they are preparing an interface where you can change Motronic parameters with the laptop like on other cars 1.8T or Subarus etc.

[Jonas_R]

The launch control? I think the potentiometer is a better idea - because if your ecu loses power you will lose LC settings as well.

Yeah the launch control. Of course it is a problem if you loose the settings. But is it easy to implement or hard?

[S2central.net]

Firstly - it would not be easy to adapt this thru VAGCOM.

Secondly - from a practical usage point of view... the beauty of a simple pot control is (a) no reliance on laptop etc to make a change and (b) it can be fine adjusted for personal taste and in different weather - dry/wet or if you have slicks on at the drag strip.

I was a bit skeptical about Dmitri's claims for how he did this, but it is rather ingenious and simple approach that just works - we had a chat about how best to make it user adjustable on the fly with some added h/w and s/w to make it a really nice option.

When flooring the gas pedal at stand still - you can adjust the pot and watch the limited rpm rise/fall to where you want them... then pray for your clutch and driveshafts before zee launch - all under driver control with one little electronic aid that produces useful boost at lower rev limit while you have the throttle mashed wide open.

[Jonas_R]

Ok I can see the advantage with the potmeter.