Psycho Dave

I was talking with a couple LT1 guys and they were telling me that you cant lock the fuel and timing maps on Lt1 edit. So basically as soon as you drive the car the computer starts relearning and setting itself to what it wants. Does LS1 edit work the same way? I dont see the purpose of buying it if you cant lock your maps to what you setup. Its still usefull for disabling things but my biggest reason for buying it would to be able to customize the fuel and timing maps and have them locked so the computer doesnt change them as soon as you get driving around. TIA

-Dave

ChrisB

Unless there is some reason you can't use closed loop feedback (e.g. leaded gas, open headers, etc) you want the computer to change the fueling on the fly?

why?

conditions are not static. weather, gas quality, etc. is constantly changing - even if slightly. The O2's give you precise feedback and allow for correction for this.

The point isn't to maintain some arbitrary fuel or timing value, but to maintain a consistent level of operation of the vehicle.

If you really want to disable closed loop feedback you can simply raise the temp to enable closed loop operation - effectively keeping you in open loop mode constantly.

Chris

Psycho Dave

Thanks Chris. Let me rephrase what I said to maybe make more sense to everyone and maybe get an answer that I understand a little bit better.

Lets say the computer has a stock baseline setup that it uses. During driving it works off that baseline to keep the car running at optimum. If you change that baseline in LS1 edit, does the computer leave it alone and just works from those new points to keep the car running optimum? What im trying to say is....If stock it gives 25 degrees advance at 3500rpm and the computer works from there to keep the car running at optimum. Then say I changed it to 30 degrees advance at 3500 rpm, does the computer work from the new setting or over time does it relearn/rework itself back to the 25 degrees it had stock. Basically what im saying is..if I change something to make the car run better or make more power, I dont want the computer taking itself back to stock settings and ruining all the work. I also dont want to be reloading the tuneup into the computer every other day because the computer changes it. So I didnt mean if I set it at 30 degrees advance I want it to stay at exactly that, I just dont want the computer taking it back to stock. I want it to work from the new tuneup. I hope this makes a little more sense. Thanks

ChrisB

The computer can not re-write it's own code, which sounds like what you are worried about.

The "learning" features of the computer are restricted to mainly s-trim and l-trim fuel functions (based on these values, derived from o2 readings, a correciton factor is applied to the base calculated values).

There is also an adaptive knock learn function where upon certain conditions a set amount of knock retard can be taken out without actually experiencing a knock event. This is the only thing that would have effect on your timing levels.

But these closed loop controls should work properly. If the amount of timing you are giving the computer is causing the knock sensor to go off then you need to find out why. It's possibly it could be false, but generally I have had good luck with knock sensors working properly. If would verify proper operation and then adjust your timing tables to prevent activation of the knock sensor.

Same with the o2's - assuming proper operation you may need to tweak certain tables (if you have changed the corresponding hardware from stock) to bring the l-trim values in line - once you have them set up properly the o2 action is desireable.

Chris