Porsche turbo boost reference timing retard

[vlad01]

what does it get its trigger from? dizzy or crank trigger?

I wonder if its using mechanical advance and some form or electronic trigger in the dizzy?

[Jayme]

it would be a fun thing to try, but the first ting I would do is lock the trigger (Assuming its mechanical advance of the trigger and not an ecu of some sort) then put an 808 on it, even if its spark only, then run the reference wires from one DFI to the 808, then tee off the bypass and EST wires to go to both DFI's. from what I understand of how they work, that ~should~ allow both to be controlled by the 808 at once. then you can just put a 2 bar sensor on the 808 and run nicely boost referenced spark map.

of course another alternative would be to throw away one DFI module and hook it up to an 808 as per normal, then use one of VL400's DFI > Ls1 coil signal converters and just double up on them to run 12x ls1 coils hahahahahahhaahah

[vlad01]

what signalling does the all those use on the DFI?

I thinking it should work on what you said, maybe some buffer in between?

only thing is how to get a signal crank trigger to operate both DFI? I would imagine the hall sensor might not drive 2 DFI at once due to the signals maybe too weak being spread across both? idk. i feel like wiring 2 together on my car just to see haha.

[VL400]

it would be a fun thing to try, but the first ting I would do is lock the trigger (Assuming its mechanical advance of the trigger and not an ecu of some sort) then put an 808 on it, even if its spark only, then run the reference wires from one DFI to the 808, then tee off the bypass and EST wires to go to both DFI's. from what I understand of how they work, that ~should~ allow both to be controlled by the 808 at once. then you can just put a 2 bar sensor on the 808 and run nicely boost referenced spark map.

I think that would work to run the two DFI modules, and would be like a new car with the much improved spark control. I am not sure how the dizzy pickup is being used to control a commodore DFI plate though, assuming its a standard dizzy setup of either points or a basic electronic pickup? They need the 18x3x signals to be able to send spark to the correct coil.

of course another alternative would be to throw away one DFI module and hook it up to an 808 as per normal, then use one of VL400's DFI > Ls1 coil signal converters and just double up on them to run 12x ls1 coils hahahahahahhaahah

This would be cool, soooo much spark energy. Could also use my programmable module and do away with two DFI base plates, even though it only has 8 outputs can drive two coils from one output in this case (it actually handles 4 cyl dual spark setups with individual drivers, some toyota engines use this).

[Gareth]

Here is what im sure is controlling the DFI and a photo of the pickup if that helps. It has one of those modules per coil bank.

[antus]

You should have a close look at the dfi modules. The circuit underneath may be the american trigger pattern and be different from the aussie commodores. The american trigger system is easyer to work with. It has 3 connectors one side rather than a rectangle one on the end of the dis.(just going off the top of my head here, not something i regulatly work with)

[Jayme]

looking online.... this may not be a GM dis at all..... apparently pacific motorsports (now dead) made them custom to suit 911's using a 60-2 crank trigger, the coils on top may look like commodore coil packs, but thats where the similarities end.

I think the easiest method for you would be to replace the entire system and use VL400's custom ignition module to read the crank trigger directly and drive 2x coils per output.

[Gareth]

I think the easiest method for you would be to replace the entire system and use VL400's custom ignition module to read the crank trigger directly and drive 2x coils per output.

excuse my dumbness, but... how does one of them know where boost is at and how to react to it? do I need to add an 808 and map sensor to it?

Looks like a handy thing that could fix a few other jobs we have on the go..

[antus]

Is there a maf sensor or map sensor connected to it? If not then it is just advancing with rpm like a weighted distributor with no vaccume advance would, with the only advantage being better dwell times and bigger spark than stock. Still far from optimal.

[Gareth]

no MAF or MAP, like me - dumb