DIY ECU Interceptor

Dras · Post by **Dras** » Tue Jun 09, 2009 11:23 am

Hi All,

After a few mods on my GR, I am thinking of getting an ECU Interceptor for a bit of fine tuning. My problem is, they are all expensive. Being a software/hardware Engineer, I am thinking of making my own.

I believe I can put together an Interceptor kit for the FTO that will modify the air/fuel ratio in open loop mode and the ignition timing using a laptop and nice windows software for about $100. I am thinking the kit will only kick in when the engine is warm and settled so as to avoid cold/warm start issues.

My first question is, if I do this, would their be people interested in buying a 'solder up your own' Interceptor kit for this sort of price?

Secondly, are there members out there with tuning experience that would contribute knowledge to the project regarding how the interceptor should work (ie which signals should be monitored / modified) and how the windows software should look so that dyno tuning places will actually work with it?

Post by **Bennoz** » Tue Jun 09, 2009 11:58 am

Ever played with EVO scan? I'd be basing yoor project on that. To start with you get the cable to talk to the ECU plus you get software to monitor everything you could imagine. From there you just need to be able to modify the signal going through the ECU to make changes.

http://www.limitless.co.nz/

I've got a both the cable & software if you wanted to fiddle with that.

Dras · Post by **Dras** » Tue Jun 09, 2009 12:09 pm

Thanks Bennoz,

I have seen that project and have already ordered a cable (should be arriving any day now). I also have the specs of the protocol so that my unit will directly be able to get to these readings.

This would mean that the Interceptor unit would give you access to everything the cable does as well as the ability to make changes / log results and all for about the same price as just the cable.

Storm · Post by **Storm** » Tue Jun 09, 2009 8:00 pm

That sounds excellent. The EVOScan is a good tool but once yourealise your car is running the way it should be it kind of gets stale and sits in the glovebox doing diddly squat.

Being able to use it to fine tune the engine would be cool and I for one would pay carraige to sunny Scotland if the price was right.

Bill

Dras · Post by **Dras** » Wed Jun 10, 2009 9:52 am

Ok, after some thought, the way I would like to approach this is as follows:

Monitor all of the sensors using my Interceptor. Once the car has warmed up and is in open loop operation, my Interceptor takes care of driving the injectors and spark plugs. This way I am not confusing the ECU, I am just ignoring it's outputs.

The downside of this is that I will need to map out the existing functions of the ECU as a base. My plan is to simulate the sensors of the car in my lab so that I can relatively quickly read out all the info I need.

Does anyone see anything obviously wrong with my plan?

Does anyone have a GR ECU they could loan me on a 'you break it, you bought it basis'?