My timing map suck?
Apr 19, 2007, 02:45 PM
#31
I think you are cought up in trying to prove me wrong, that you failed to comprehend what i'm saying. Please re-read all of my posts. You are arguing semantics at this point. What i have been saying all along is this; adding fuel to slightly over advanced ignition timing can and will help combat knock. It's not a good thing to do at all, it's bad for power and safety. But to a certain extent it's possible to do. It happens all the time. Tuners do it, piggybacks do it. It's not proper at all. What i have also said, that if ignition timing is too overadvanced, adding fuel will not help the situation. So, you are arguing about nothing at this point, because nothing you are saying now, is anything i have not already said.
Fact is, you are agreeing with what i'm saying, but you don't realize it.
70% of your combustion chamber temps get extracted out of the combustion chamber VIA the spark plug, which acts as a heatsink to the head and from there the heat is obsorbed into the coolant. EGT's will be higher as ignitin timing is retarded, the more you retard ignition timing, the higher the EGT's. Say you start off at 10* ignition timing. EGT's are at xxxx*F. As you advance ignition timing, EGT's should go down, once you hit peak torque output, EGT's should go back up a bit. Once you go past peak torque output, EGT's will start to fall again, because you are loosing power. You might be 2-3 degs under the detonation threshold, but still loosing power. EGT's will obviously show lower, because of the loss of power output. Just because you are on the other side of power output does not mean you are automatically detonating. You could have another 2-3 degs of advance left before you reach the detonation threshold. Some of that is what you are saying about the heat being able to escape the combustion chamber because it has a longer time to be exchanged. That does not necisarliy mean you are experincing detonation. And your right, Throwing more fuel at it at that point won't make a difference.
anyway, i enjoy a good volly every once in awhile. But let's keep this thread on track. Let's not hijack it any longer(although this info pertains to the thread)
CJ
Fact is, you are agreeing with what i'm saying, but you don't realize it.
70% of your combustion chamber temps get extracted out of the combustion chamber VIA the spark plug, which acts as a heatsink to the head and from there the heat is obsorbed into the coolant. EGT's will be higher as ignitin timing is retarded, the more you retard ignition timing, the higher the EGT's. Say you start off at 10* ignition timing. EGT's are at xxxx*F. As you advance ignition timing, EGT's should go down, once you hit peak torque output, EGT's should go back up a bit. Once you go past peak torque output, EGT's will start to fall again, because you are loosing power. You might be 2-3 degs under the detonation threshold, but still loosing power. EGT's will obviously show lower, because of the loss of power output. Just because you are on the other side of power output does not mean you are automatically detonating. You could have another 2-3 degs of advance left before you reach the detonation threshold. Some of that is what you are saying about the heat being able to escape the combustion chamber because it has a longer time to be exchanged. That does not necisarliy mean you are experincing detonation. And your right, Throwing more fuel at it at that point won't make a difference.
anyway, i enjoy a good volly every once in awhile. But let's keep this thread on track. Let's not hijack it any longer(although this info pertains to the thread)
CJ
.
Apr 19, 2007, 06:45 PM
#32
Using an overkill of timing, slowing the burn rate with fuel, and using ECU knock retard as the tune is not really tuning. It's basically what comes from the factory in conjunct. with the low octane mapping so it can survive Joe consumer driving his car on low octane fuel.
One thing I know for sure, even with the trivial exp and knowledge I have, is that a tune that uses the quickest burn rate possible, and optimal timing in regards to that mix is by far a superior tune to the one that's tuned on ignition first and controlling the rate of burn with fuel (no wonder fp upgrade is prerequisite).
In an ideal world - 12.5:1 A:F with optimal timing, but in the real world when using the OEM ecu, which in itself is bubba engineered and done so rather nicely, were forced to find a happy medium for now, but the further your go in the above direction the more work it takes and even safer too.
Glad I could share my opinion
One thing I know for sure, even with the trivial exp and knowledge I have, is that a tune that uses the quickest burn rate possible, and optimal timing in regards to that mix is by far a superior tune to the one that's tuned on ignition first and controlling the rate of burn with fuel (no wonder fp upgrade is prerequisite).
In an ideal world - 12.5:1 A:F with optimal timing, but in the real world when using the OEM ecu, which in itself is bubba engineered and done so rather nicely, were forced to find a happy medium for now, but the further your go in the above direction the more work it takes and even safer too.
Glad I could share my opinion
Thread
Thread Starter
Forum
Replies
Last Post
RoadSpike
Lancer Engine Management / Tuning Forums
36
Sep 12, 2014 08:33 AM
