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tonight, I was bored, and I had a few extra hours befor eI call it a day, so I figured "hey, why dont' I datalog chris's car while it is running good to see what it is doing" so I drove it around and the fuel trims were at -25% (yes, fuel TRIMS...plural...I will explain that later)I took it down my little "road course" (anybody that has been over to the house knows about that :-P) and the car had crappy timing...about 10 to 14 degrees advanced at wot (I assumed it was from not having an fcd. no biggie). I also noticed that short term fuel trim goes to 0 at wot. I figured it out (this is also why teh car runs and idles fine with 525 cc injectors). there is a short term fuel trim and a long term fuel trim..........they ADD UP. the ecu reads the o2 voltage while it idles and adjust th eshort term fuel trim and then adjust th elong term fuel trim (which stays constant through the entire rpm range). jsut so happens max is -25%. well, while th ecar is driving around or idling, the ecu adds or subtracts to that figure by however much necessary to bring th eo2's into a respectable range (after the o2 sensor has warmed up of course) at idle, the ecu leans it out another 25%.....making it a total of -50% adjustment from the "factory". I watched th ecar do this with my own eyes. you could hear the tone change after a minute or so of it adjusting. and at wide open throttle, it seems to dump the right ammount of fuel for boost (it looks like it is figuring out the fuel needed by throttle position and rpm). so then, I was like......hmm....the timing is crappy, adn th ecar is running safely rich.........let's try the ever coveted AFX ECU (light shines from heaven). so I took it out of my car (which will have to have another cylinder sleaved, and said my prayers :-P. checked the compression and plugs before doing it. plugs looked good, and compression was 175 across the board. after putting it in, car started adn did it't fuel trim magic. then I had to fight with it to stay connected to th elogger (my ecu has ALWAYS been retarded like that). and I finalyl got it to stay connected. timing stayed between 18 and 24 (averaged about 21) still with no type of fcd whatsoever. I thought that was pretty dang cool. and with the new extra 10 degrees of timing came a new 30-40 some seat fo the pants wheel hp  . I kid you not, the car felt almost as fast as my car at 18 psi......and yes, th ecar ran 18 psi without a hitch. egt's between 1300 and 1400 on the gauge, and air/fuel pretty rich. the car was strong enough to spin "both" front tires from a roll in 1st and second gear just like my avenger (and chris's car has soem HEAVY 17x8 tsw revo's with some pretty good sumitomo tires......it couldn't spin them like that before). I was amazed. it pulled great and ran me into the corners HARD. I stoped FREQUETLY to check the status of the car, and it was still doing perfect. I also wanted to see where this new "rev limiter" was on the car (take in mind that chris's car is now using the afx fuel curves and not a dfi). car it rev limiter at 7800 rpm (a hair away from the advertized 8200 rpm but better than th estock 7300 rpm fuel cut. I don't think chris's ca ris ready for that high of an rpm yet anyway seeing as how it slung BOTH acessory belts off, so the car had no alternator OR power steering after that test. no biggie. I can get belts later. and to top ALL this stuff off. th ecar NEVER got a map sensor code OF ANY kind :-D with th eafx ecu. went down th estreet quite a few times and cycled the ignition quite a few times, and no error codes at all :-D. I didnt' retard timign at all because an average of 21degrees advance is "exactly" where I woudl like the car to be at this stage without extensive tuning. I may get one of those missing links for th ecar, btu that wont' be until it is ready fo rdyno testing. the car has pesky oil leaks (I suspect it is from WAY back when the motor was assembled, improper betplate sealant was used.......that is an assumption), and it has a little blow by, but nothing out of the ordernary fo ra car that has been boosted for this long. th eafx ecu drove around fine, and feld like the 0psi dip at 4 to 4500 rpm wasnt' "quite" as bad as stock, but still there. one of those missing links shoudl clear that right up, but I am not going to worry about that now. I actually had something go right for a change. car still has 175 psi of compression across the board (puts it at about 8.5 or so to 1) and plugs look a little rich. "ABSOLUTELY PERFECT". I think the only reason to have an e-manage on the car now is just to say it has one :-P
A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on............
A.D.P.
"...If you do too much, people become dependant. If you do to little, people loose hope. If you do it right, people won't be sure you've done anything at all."
bring it on...........
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. I will still put the e-manage on the car, becasue I like for things to be controlled and adjusted manually, but the car could honestly drive where ever now without it safely.
