This is a question for those of you who use programmable ECU's...

This is sort of a confusing question, so bear with me. What kind of timing advance (total) are you able to run in the upper RPM range? With my LINK ECU, I am told that I am running too HIGH timing advance... The max programmed limit currently is 30 degrees advance, but tapers off slowly 2-3 degrees as RPM climbs to 8000 RPM. Some tuners tell me that I should have only a max of 12 degrees total advance in those RPM ranges. The problem is that I make more power up there with more advance, but logic tells me that I should be getting detonation. Am I on the right track? can someone help me a bit?

 

You would need to see what the air fuel ratio is doing in the high rpm with the timing set there. As long as you are staying rich enough, then you should be fine.

 

Currently the AF ratio is about 13.2 and going up to 13.7 as RPM climbs. I see the need to add a little bit of fuel, but I am still confused on the timing issue. Can I be at full advance (32 degrees) in those upper RPM's or should it taper of slowly? What I have is a timing map that stays consistant from about 3000 RPM where it is at full advance and doest change until about 7000 RPM and drops 2-3 dregrees from that point.

 

You can run as much timing as you want as long as your fuel can handle it without detonating. The question is whether you are making more or less power. If you make more power with lots of ignition timing and your octane is high enough that you aren't detonating, then you are fine.

 

Kingtut33, I appreciate your responses. thankyou. Do you use any type of programable ECU yourself? I understand what you say about fuel limits as far as preignition, but is it common for a "programmed" ignition map to have little variance at each RPM level and throttle position?

 

Do you guys think 20 degrees on a stock B16 with 94 octane is too much advance? I think I can hear men playing marbles inside my combustion chambers - but I'm paranoid.

 

i dont' think 20 degrees is alot at all.
what i would do is try anywhere from 26~30 degrees timing with your a/f at about 12.9~13.2.

 

so, maybe get a FPR and bump it a bit? I don't think it runs that rich stock does it?