pcmhacking.net

Sooo, was pondering today what to do about the o2 sensors in the race car, old VS pcm ran two 4 wire sensors, the 424 runs one... Was thinking that id run the wideband in one side and narrow band in the other and just swap them from side to side from time to time. Then after much JD, i got wondering is the 424 is capable of reading from both sensors as far as the wideband side of the sensors goes?

Id guess that there is possibily a hardware limitation?

Any ideas on the best ways to approach this issue?

Whilst thinking about the issue, i realised that the wideband lead is waaaay too long, was going to upgrade the connectors to DT series while i was at it, but then realised that the spart has the controller built not only into the lead but onto the connector, fuck...

So i pulled it apart to see how hard this problem really is, too some photos for anyone interested...


That wideband is about a meter long out of the pack..

A little trick there, so as to not cut underlying circuits or wires, just score the heat shrink and then reheat and watch it pop open..


I thought this was a cool pic of the shed...

You could log 2 with one of VL400's loggers if that helps

Yeah that does, ive got one of them...

V1 or V2?I have a V2 I'm just setting up for the first time. VL400 has done some great instructions even with pictures but I'm still struggle. never modified an ADX before. I posted my attempt in the V2 thread. Hoping someone who knows can check it for me hoping to log a mates wingless sprint this weekend. You get them up your way?
Once I get it right I could help you if you already know maybe you could help me?

V2, used it to log our workshop VT for a short time only. It came ready to suit that car.

I too am an ADX virgin would love to help, but im not the person for that, yet..

There aren't many wingless sprints in our area, maybe 2 i can think of.. Never tuned one, have seen tunes for them, pretty extream timing figures from memory

Care to share? Not real sure on the timing methanol can take. And only guessed the VE. I know the drilled injectors couldn't take much fuel before they killed spark due to no spray pattern I was guessing.

Isn't there spare analogue inputs on the ecu you can just plug into?

Methanol: very roughly +5 degrees?

Also with the wideband cable, not sure on that type of connector but i believe the bosch units have a calibration resistor in the connector. If you change the wire or plug you may effect the readings. Decide if thats worth the risk and maybe take some baseline readings from a car in a known state (idle at x degrees temp) and repeat after modification to test for changes that may have been caused by the cable mods?

yeah methanol wants a bit more timing due to the slower burn rate!

as for extreme timing figures, what do you call extreme ? when I tuned a V6 sprintcar on the dyno it only wanted about mid 20's in the most part for max torque!

as for the logger .... if you use an adx that's already setup the log the analogue inputs you probably only need to change the display settings and the calc for it .... also note that if the calc is too complex the logger can't do it, but I can probably help with a bit of that I have done a few adx's for different cars of my brothers and such.

Isn't there spare analogue inputs on the ecu you can just plug into?

not sure... If it is possible, would it have an effect on the 'VE learn' or will that only work off of the signal of one sensor? If that is the case, maybe I should wire for one sensor and fit two and just swap the plugs around often? The exhaust on this car is a full twin system - no balance pipe.