Quote:
Originally Posted by smoked240
Very helpful info!! I'll pull up my map tonight and do some adjusting. My timing on the aem shows 36* while boosting but I'm assuming you subtract the 15* the timing was synced at?
Thanks for the help!
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no, no.
You set the timing in the ECU to match the crankshaft. I go over how to set sr20 timing in several threads. You need to verify the timing matches the crankshaft, or else nothing you do will matter and the engine will blow or give terrible performance/economy to say the least.
Once you can see (some number) at the crank, and it matches some reported number (at the ECU) then you check multiple rpm: does it match at idle? 2000rpm? 4000rpm? Make sure it always matches up.
Then you can make your changes. If you want 9* in boost you put 9* in the map. It runs where you tell it to. There are trims in the ECU "behind the scenes" such as TPS trims and coolant trims, AEM has more trims than I can count. So you have to go through the entire instruction manual looking for all the timing trims or at the very least be sure you are getting the timing you think you are getting.
It is very common for "tuners" to over time the sr20det engine. 36* is way too much timing. What does your knock sensor say about that? Further more the a/f should be consistent. It should not jump 10x units (from 13 to 14 for example) while holding steady throttle (steady vacuum signal) the only "jumping" it should do is from 14.5 to 14.8 during closed loop operation, such as cruise and idle, off the narrowband Oxygen sensor, if closed loop is enabled. A good fuel map has very gradual, smooth changes.
random example, notice how it smoothly goes from one value at the bottom to another at the top, there are no jagged areas, no dips or crevices "pot holes" in the map, the engine will transition smoothly and the a/f remains consistent when you hold a load value.
http://smg.photobucket.com/user/jonb...emmap.png.html