Anyone convert from drive by wire (DBW) to cable?

[Hobby Racer]

My 2006 WRX donor is a DBW car and I am considering using an aftermarket ECU that does not support DBW (MegaSquirt 3). I will need to convert to a cable operated throttle body. I was wondering if anyone has experience with this?

Do you only need to swap the throttle body from an earlier WRX? Or is there more involved? Also are the 2.5L EJ255 throttle bodies a different diameter than the 2.0L EJ205's?

[michael everson]

I don't have an answer for you, but might be interested in your DBW setup if you decided to change.
Mike

[Aero STI]

The bolt pattern between the DBW and DBC throttle bodies is slightly different, so the easiest swap is to change manifolds. I have a ported and polished DBC manifold if you really want to go down this route.

I've followed the MegaSquirt development for quite some time and actually have a complete setup waiting to be soldered up and installed in a car. In my opinion, installing a megasquirt instead of the factory Subaru ecu, especially the 32 bit version on the '06+ WRX, would be a step in the wrong direction.

What is it that the MS3 offers that the factory ECU does not?

[Hobby Racer]

What is it that the MS3 offers that the factory ECU does not?

I've squirted my FFR roadster and love the tuning flexibility. But for the 818R I'm planning I like the following benefits of the MS3 over the factory ECU.


Streamlined wiring (most of the factory harness is not needed in an 818R)
Built-in water meth injection control
Flat shift features.
Ability to log additional sensor data
But most of all the live tuning!

[TahoeTim]

Wayne is working with MS on my behalf to develop the dbw interface. I think they are very close if you want to wait.

[Hobby Racer]

Wayne is working with MS on my behalf to develop the dbw interface. I think they are very close if you want to wait.

Wow, that would be amazing. Keep us posted!

[Aero STI]

Streamlined wiring (most of the factory harness is not needed in an 818R) - Valid point, but factory wiring can be stripped way down
Built-in water meth injection control - Ok, sure. I stopped messing with meth injection 8 years ago and never looked back, but any new micro-controller and a few sensors could best current meth controllers
Flat shift features - LC, ffs, anti-lag are available with open source or Cobb Accessport
Ability to log additional sensor data - the unused sensor wires, like TGVs, can be used for logging other sensors
But most of all the live tuning! - available with Accessport


Regardless, you've got to go with what you're most familiar and comfortable with.

[Hobby Racer]

Ability to log additional sensor data - the unused sensor wires, like TGVs, can be used for logging other sensors


How does the ECU know the old sensors have been re-purposed and how will they appear in the logs?



But most of all the live tuning! - available with Accessport



I didn't know that. I had been researching the opensource alternatives and they do not offer live tuning. I will have to rethink my options now.

Thanks.

[JeromeS13]

How does the ECU know the old sensors have been re-purposed and how will they appear in the logs?
Thanks.

The ECU doesn't "know" anything has changed. It only sees a voltage input from the TGVs. So, you just have to log TGV voltage and you'll get the voltage of whatever you have coming from whatever sensor you choose.

[Hobby Racer]

The ECU doesn't "know" anything has changed. It only sees a voltage input from the TGVs. So, you just have to log TGV voltage and you'll get the voltage of whatever you have coming from whatever sensor you choose.

Might that cause the ECU to "act" on those inputs. Since the readings would not be what the ECU expects.

Other than the TGV, what other inputs could be re-purposed as I would like to log 4-5 new sensors that don't currently exist.