I was killing some time today by going through F-body schematics and noticed that it would be pretty easy to make the timing run straight up (no electronic advance or retard). I understand that this is the same as disconnecting the EST wire, but does anyone know if this could be of advantage in everyday driving? I know it would help fuel economy if you were getting false spark knock, but conversely it would hurt fuel economy if the timing were advanced. I haven't messed with turbos or nitrous much yet, so I wonder if you could connect a relay on the wire and have it pull out all advance when the turbo/nitrous kicks in.

The red switch is the bypass switch/relay of which I'm speaking.

NOTE: Even though I've indicated VIN E, all the wiring for all engines in 1991 are the same with the exception of a color stripe down a wire here & there.

 

It would be a SLUG!!, terrible fuel mileage, barely idle, etc.

 

Under normal circumstances, yes...but I'm curious if it would be a good thing under nitrous/turbo. It could really simplify some things or could even be a fail-safe if there were a problem. It would, however, idle just the same as my car does in the morning when I first key on -- when the car is in open loop.

 

Your timing still changes when in open loop. If you lock it out it's either going to be a dog at part throttle because it's too retarded, or it's going to knock like nuts at WOT because it's too advaced.

The only time running locked timing is a good idea is if it's in an all out race motor that spends most of it's time at WOT. Have you ever heard guys reving the crap out of their motors while sitting still to "clear" them out? They do this because the timing is so far off at idle and part throttle it causes them to load up with unburnt fuel. If your getting spark knock fix that problem first.

 

This wasn't a "fix" for spark knock. I was just looking through schematics and became curious. I did not know that the spark advance changed in open loop, though.

 

The power of computers is that your able to give the engine the exact timing that is required to make max power under any condition or load. With it locked out your only able to make max power under one condition and load. What you really want to be able to do is have complete control over your timing. The only way to do this with your stock ECM is to look into DIY chip tuning. Then you'll have the power to do anything you could imagnine with your timing.