1G Parallel Ecu (stock + standalone) possible?

[Gonza97]

Greetings Group, I´ve been searching about this topic with not many info about it.
I´m currently planning in advance how to tune the car in the future by going with a standalone system, but I also would like to keep oem functions like cruise control (I DD my car so I use it as a commuter and also as the intended sports car). I´ve been reading that there is a possibility to use both ECUs in parallel so I can evade searching for reverse engineering chances on a standalone.

Now my question/s, is it possible or it has considerable drawbacks to take into account? or if I need supporting mods like bigger battery or upgraded alternator? Complexity?
Thanks in advance.

And just in case before someone mentions to use ECMlink, yes I have it in mind but I´m not from US so in my case I´ll have to import it and then IDK where to install it (first of all I still don´t know if my ECU is EPROM to socket) and later on have someone who can tune the car with it (which is not the case and I´m thinking about going with the local tuner´s trusted choice of EMS for peace of mind).

 

[steve]

The cruise control computer IS a second box. As long as you keep it connected to it's inputs and outputs the ECU type shouldn't impact it. If your ECU choice and engine mods stray too far from the normal then it might not work very well.

I'd suggest you not consider any tuning options that are piggyback to the factory ECU (Parallel ECUs) other than the common SAFC. The factory ECU hardware and software limit what fueling and timing changes a piggyback can make without introducing compromises.

So either get ECMLink or get a full standalone or keep your modifications to what a SAFC can manage. (Or convert the car to another Factory ECU, if your tuner knows how, like an EVO VIII or 98/99 DSM ECU).

 

[Gonza97]

Thanks for your reply Steve.
Kind of a noob question but what do you mean by the cruise control being a 2nd box? it doesn´t rely on the OEM ECU and it´s just an add on to the DSM?
In the hypothetical situation that I go with a standalone, call it Fueltech, AEM, etc... the 1G doesn´t need to get it programmed to an aftermarket ECU?

 

[steve]

As far as I know there were two different types of cruise controls on 1G's, the mechanical actuated system found on the 90 cars and the vacuum actuated system used on the rest. I'll discuss the 91+ type.

There is a control unit that operated/controls it's function just like there are other control units in the car for ABS or Automatic Transmissions. The FSM shows their locations.

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I don't have a 94 FSM handy but the 91 FSM Electrical manual shows of the FSM connections for the Auto Cruise Control Unit for MT and AT configurations. (the Engine/Chassis/Body discussed the operation and adjustments under Fuel System) You'll note that several sensors are shared between the ECU (MPI Control Unit) and this control unit, most notably the TPS, IPS, and VSS. If you interested in the AT version look it up in the FSM.

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[enriquez2000]

Switching to a stand alone should not affect cruise control or abs
.. unless you eliminate cruise control or abs parts. These components are not tied into factory ecu and is why they have there Own control units.

 

[Gonza97]

Great stuff to know pals. Thanks both Steve and Enriquez for your input.

 

[enriquez2000]

Great stuff to know pals. Thanks both Steve and Enriquez for your input.

@steve Is the genius.. i just play one on tv