Is It Possible To Run A V8 32V With 2 I4 16V ECU's And Harnesses?

[Nollywood]

Yeah, yeah, it sounds outlandish.

But as the topic states - is it possible to run a V8 32V engine with 2 independent I4 16V ECU's and harnesses? Obviously, VR might need to be shared by using a splitter, and individual fuel pumps and control may be required.

Are there any possibilities?

Thanks guys!

[Dan[FN]6262]

The B6 S4s have one ECU per bank.

I'd be interested how a crank signal would work, but otherwise I think it is possible. Would I want to do it myself? No.

[Nollywood]

The B6 S4s have one ECU per bank.

I'd be interested how a crank signal would work, but otherwise I think it is possible. Would I want to do it myself? No.

Crank signal splitting is quite common. Some owners run stand alone in conjunction with the original ECU, sharing a common VR sensor.

The reasoning behind this is the factory ECU keeps the instrument cluster, ABS, automatic transmission (if fitted) and climate control happy, while the stand alone or piggy-back system runs the motor. So a split VR output is very feasible.

[walky_talky20]

I don't think separate fuel pumps or control is necessary. As long as there is enough flow and pressure to the rail (even if the pump just runs constant on the 15 circuit), it should be just fine.

Separate control of ignition coil power supply is probably a good idea, but that would be sort of existing in each harness anyway.

[Dan[FN]6262]

Okay, curiosity has got the best of me, I have to ask lol... Why not use a factory V8 harness and ECU? Why do you want to make two 16v ECUs work? Not being a smartass or anything, serious question.

[chris164935]

I suppose as long as the firing order alternates between the two banks of cylinders, it could work. Or, if you can program the ECUs to talk to each other so that they know when to spray fuel if the firing order does not alternate between the two banks of cylinders. And the same would most likely be true for the ignition as well. Each ECU would have its own wideband O2 sensor. Depending on how many of other sensors it has (1 or 2 IATs, coolant temp sensor, etc.), the ECUs could use their own respective sensor or share signal of one sensor. Sounds like a wiring nightmare though... Not to mention you'd have to program/tune 2 separate ECUs.

[Nollywood]

I don't think separate fuel pumps or control is necessary. As long as there is enough flow and pressure to the rail (even if the pump just runs constant on the 15 circuit), it should be just fine.

Separate control of ignition coil power supply is probably a good idea, but that would be sort of existing in each harness anyway.

Thanks, Walky. I was hoping you'd chime in.

[Nollywood]

Okay, curiosity has got the best of me, I have to ask lol... Why not use a factory V8 harness and ECU? Why do you want to make two 16v ECUs work? Not being a smartass or anything, serious question.

Boost. Lots of it.

[Nollywood]

I suppose as long as the firing order alternates between the two banks of cylinders, it could work. Or, if you can program the ECUs to talk to each other so that they know when to spray fuel if the firing order does not alternate between the two banks of cylinders. And the same would most likely be true for the ignition as well. Each ECU would have its own wideband O2 sensor. Depending on how many of other sensors it has (1 or 2 IATs, coolant temp sensor, etc.), the ECUs could use their own respective sensor or share signal of one sensor. Sounds like a wiring nightmare though... Not to mention you'd have to program/tune 2 separate ECUs.

I've been looking at the ignition and injection maps, and the firing order of both the 1.8T and the V8 32V.

1.8T: 1-3-4-2
32V: 1-5-4-8-6-3-7-2

Each ECU will not be strictly controlling individual banks, the injector and coilpack connectors will need to be cross bank wired.

It's not impossible, the wiring wouldn't really faze me, that's the easy part. The hard work would come much later. Still, the pursuit of horses isn't easy.

[Wrath And Tears]

So the point is to have a v8 twin turbo? I could see using the 1.8 ecu with a standalone. If you want big boost you will probably need to go standalone anyway due to the unique set-up. This is all if you are looking to keep the wiring as simple as possible.

If you really want to split everything besides and add an additional 50 pounds of wires no reason you couldn't use two 1.8 ecu's in parallel. But then for big boost you would need to get them chipped. Unless you can get a deal it would be like $1500-2000 just to get a tune on both ecu's (if you need both of them tuned, and couldn't get some kind of discount).

Another way would be to split the work load of the two ecu's. Basic example is that only one ECU would be in charge of the engine while the other is in charge of cabin stuff, so technically you would only need one chipped. This is pretty much the same as running a 1.8ecu with a standalone.

Out of everyone I think you are the person to find out for us Nolly.

[Dan[FN]6262]

Boost. Lots of it.

LOL then why go about it in the most difficult way possible?

Standalone all day long. You could even build one using a factory V8 harness and/or ECU socket. Then you would have throttle modulated boost, meth, no lift shift, launch control and NAWWWSSS being controlled all in one box.

Don't get me wrong, turbo V8 for the win, but don't make it harder on yourself then it is going to be, if you are serious

[Nollywood]

Thanks for your input, Wrath, I appreciate it.

In my case, there's no instrument cluster to keep happy, not in the CAN sense. The cluster will be replaced with a STACK dash, and there's going to be no climate control or interior to think of.

I'm not a tuner, at least not with Motronic. But my buddy is, I shall be liaising with him a lot on this project.

[andyrew]

If your going to code the heck out of a couple of ECU's I would agree it would be way better to just start with one ECU and go from there. It should be WAY easier to manage than to have to split a bunch of different sensors.

Seriously... that seems like a LOT of additional work.

If your thinking of doing that why not just go megasquirt on the ecu?

[Nollywood]

If your going to code the heck out of a couple of ECU's I would agree it would be way better to just start with one ECU and go from there. It should be WAY easier to manage than to have to split a bunch of different sensors.

Seriously... that seems like a LOT of additional work.

If your thinking of doing that why not just go megasquirt on the ecu?

Thanks for your input, Andy.

I have considered a single stand alone. I used VEMS previously, which is a more updated Megasquirt. I didn't like it. I actually loved my old MK2 1.8 16V turbo, (pre-1.8T) which ran Lumenition. Made 342hp back in 1994, it was the best stand alone I've used. Sadly, Lumenition no longer exists.

MoTec is top notch, but also big money.

I would rather go with Motronic info other option exists. I like the OEM feel, the rock steady idle and ease of starting in all conditions. I also understand Motronic more, despite not being your average tuner, and I have more support too.

[chris164935]

AEM Infinity ECUs are one good option. Another are the Link G4 ECUs.

I'm using the Vi-PEC i88 ECU. It is the high-end version of the Link ECUs. But, the software is pretty much the same. It's very simple to setup and use. I've never messed with a stand-alone system before but I've learned a lot using the Link software. The Help section of the software explains pretty much EVERY aspect of every available option in the software. It's great.

[Nollywood]

LOL then why go about it in the most difficult way possible?

Standalone all day long. You could even build one using a factory V8 harness and/or ECU socket. Then you would have throttle modulated boost, meth, no lift shift, launch control and NAWWWSSS being controlled all in one box.

Don't get me wrong, turbo V8 for the win, but don't make it harder on yourself then it is going to be, if you are serious

My apologies for responding this late, I must have missed your post yesterday.

Points taken, I can understand where you're coming from. I will look into a decent SA, or a piggy back system that will run alongside the stock Motronic.

Thanks again.