WRX9/10 ALS + Launch I/P

[Robbied]

Hi,

Almost finished the install of a WRX9/10 and SDC 3 into a 2009 Impreza, couple of questions still remain however!

The car has a rotary pot previously used as anti-lag. (0-5V output essentially). Can I use OEM pin A3 (M800 Channel AT5) for this input? Cut link 3, join link 1 by the looks of things?

I need an input for a start line RPM limit switch, (pulled to 0v when pressed). Is there a spare input I can use for this?

Many thanks,

-Robbie

[mrsaturn7085]

There are some inconsistencies within the white paper regarding pins A3, B14 and the fuses required for the use of each input pin - verify with a multimeter, it's not difficult at all.

Pick two from AT4, AT5, or AT6 for the rotary pot and grounding switch (for reasons explained below, I suggest AT4 for the grounding rev limit switch). Some modification of the factory wiring will be required for each. DIG1-4 and the other AT inputs will all be used up on that model year.

Now, as far as I've been able to figure out, you're probably not going to be able to have the rotary switch working like you want... but you might be able to get creative with it. The problem is that there are no provisions in the M800 for rotary pot ORB map switching (as a voltage divider). What you *can* use a resistance based rotary pot for is multi-map switching (meaning FULL map switching, between two or three configurations files), or you can use the rotary pot for a trim axis input (i.e. trim pot).

Since the rotary switch is not suitable for a straight-forward selection of ORB modes (off/mild/full) here's a few ideas for you:

1. Use three multi-map configurations that are identical except for ORB settings. Config one is ORB disabled, config two (AT5 grounded) is ORB mild, and config three (AT6 grounded) is ORB full. In both config two and three, the ORB mode is "3" (throttle based - no activation switch). The rotary switch has a logic table as follows:

Position 1 - AT5 = high, AT6 = high
Position 2 - AT5 = low, AT6 = high
Position 3 - AT5 = high, AT6 = low

*search other threads regarding multi-map switching to understand the need to use AT5 and AT6

2. Configure the rotary switch (electrically) to act as two switches (corresponding to input functions 13 and 24). The logic table differs from the first suggestion, above, and you have a little more freedom in selecting which AT input you use from AT4/AT5/AT6:

Position 1 - Function 13 = off, Function 24 = off
Position 2 - Function 13 = on, Function 24 = off
Position 3 - Function 13 = on, Function 24 = on

*take care in designing electrical circuit using a rotary switch - diodes may be necessary to get it to work this way

In all cases, you will need to use AT4, AT5, and AT6 to get this all working. I suggest using AT4 as the ground switch for the RPM (launch) limiter so you don't prevent yourself from using method 1, above, if you choose method 2 and then later change your mind.

Is the car an old Prodrive car that was running Pectel before? Sounds like how they had the ALS and launch set-up on those cars. If so - I might have a few questions for you if you have some time.

[mrsaturn7085]

One other quick note - I recommend method #2 as I am not sure if you can switch the multi-map config with the engine running... I have yet to play with this function to test it out. I'm pretty sure map switching would require an ECU reset... the engine *might* stay running, but you might stall.

[Scott@FP]

Set up the multiposition switch as a custom sensor on a user channel, set up the cal so it outputs values from 1 to 9, use this on any axis in any table. Make sure the sensor cal eliminates any hysteresis issues.

[Robbied]

Thanks gents, very helpful.

We ended up using those AT inputs as couldn't see any other spare channels, the engine uses most of the PnP inputs already as far as we made out.

We ended up being a little crude and using a 3 position toggle for ORB off/1/2, and then the 3rd input for a the RPM limit. It kept it inline with the customers other car so at least the ORB switching was the same across the two cars.

We did however get the diff position to display on the AIM dash as a number coming from the SDC3. This is pretty neat and there wasn't really another option as the OEM clocks don't exist.

It was a car built in Europe but using a Prodrive overlay loom and yes it had a Pectel GpN/R4 ECU and a very simple but not functioning diff controller that looks like it was more at home in a Halfords showroom.

Thanks,

[mrsaturn7085]

Using the rotary pot as a 9 value axis works well IF you can do 4D maps. For many M800 maps, being limited to 3D makes this less useful.

ALS maps, and to a lesser extent, cam control (especially combined with ALS), are both maps that could easily benefit from 4D.

Robbied - could you please PM me your e-mail contact info? If you have time, I would like to ask some technical questions about the Prodrive loom. Information overseas on these cars is difficult to come by!