M84 has no "Multi Config". Can I have an E85 flex tune?

[CraigComet]

I have an M84 and an M800, and am choosing which one to fit to a pretty basic old street car that's running a turbo and just the basic temp and pressure sensors, staged fuel pumps and a couple of fans. Nothing fancy.

I'm looking at the comparison between the M800 and the M84. Other than the M84 losing the chance to use the spare Ignition Outputs as Aux Outputs, I'm leaning towards using the M84 because it already has dual lambda enabled and wired into the harness. What I'm not sure about is the M84 doesn't have "Multi Config".
What does this mean?

I wouldn't mind setting up a flex fuel tune to run 98 octane or E85 or anywhere in between. Is this a function within "multi config"?

Thanks for any advice.

[David Ferguson]

Multi-config allows a switch to completely separate configs. For flex-fuel, you will want to run compensation tables within a single config. I know it has been done with M800, and I think the M84 would have the flexibility to do this as long as you can bring in the alcohol content sensor to use as an axis in the compensation tables.

[Stephen Dean]

Hi,

You need to use an external Ethanol content controller that provides an Analogue Voltage signal out, this is then wired into AV8 (User Channel 1). This value is then used with Fuel Comp 1 as a compensation table for the Fuelling, Ign Comp 1 for the timing and Boost Comp 1 for the Boost.

[CraigComet]

Brilliant - thanks gents, that's great to know. On that basis, other than forgoing some extra I/O compared to the M800, there doesn't seem to be a reason not to use the M84.

[Sean]

I've been looking in to this recently, I think we're going to try one of these as a cost effective option. Made in South Australia.

https://www.nistune.com/index.php/nistu ... ess-detail

[CraigComet]

Thanks Sean. Everything we need and nothing more. And a small Aussie company. Perfect.

[Sean]

Thanks Sean. Everything we need and nothing more. And a small Aussie company. Perfect.

If you remember, let us know how the installation goes, we are interested to know. Thanks.