BlackGT Posted January 22, 2009 Share Posted January 22, 2009 So I've been playing with BOV's now that I am running around with my new FMIC, and I can't Vent To Atmosphere on either of my BOV's since they both leak at idle. I'd like to VTA, because I get a lean dead spot after I accelerate (& get into a bit of boost), then lift off the gas a little bit. As you can see in the log titled "light throttle lean after boost" when my BOV vents back to the intake (upon slight throttle lift - like after I have made the pass), the AFR reads about 18:1 for a while, this is in load cells where it should be 14.7:1. How do you tune for this? I've also attached a log that shows me holding steady throttle opening, and the manifold relative pressure is hovering around 0, you will see a little ways down the log that the AFR suddenly turns lean. Any help is appreciated. Thanks, Jeremysteady state lean log.pdflight throttle lean after boost.pdf Link to comment Share on other sites More sharing options...
mwiener2 Posted January 22, 2009 Share Posted January 22, 2009 is the engine under load or overrun in this lean spot? My Mods List (Updated 8/22/17) 2005 Outback FMT Running on Electrons Link to comment Share on other sites More sharing options...
BlackGT Posted January 23, 2009 Author Share Posted January 23, 2009 is the engine under load or overrun in this lean spot? Its under light load, about 11-20% throttle opening, maybe calculated load around 1.0. thanks for looking, Jeremy Link to comment Share on other sites More sharing options...
mickeyd2005 Posted January 23, 2009 Share Posted January 23, 2009 Tune your MAF scale before something bad happens. Link to comment Share on other sites More sharing options...
BlackGT Posted January 23, 2009 Author Share Posted January 23, 2009 Tune your MAF scale before something bad happens. I hear you, certainly a valid point with that much A/F trim learned, but why would it run the asked-for AFR for many seconds, then go lean just like a switch? Could it be that I passed some sort of threshold into open loop? I'm also confused how I could be so far off with the intake calibration. I have a K&N Typhoon with an X02 FMIC, and I used the intake cal that was posted up on RomRaider for the same combo. I probably should just stop being lazy and tune the intake... Thanks for your help, Jeremy Link to comment Share on other sites More sharing options...
mickeyd2005 Posted January 23, 2009 Share Posted January 23, 2009 Log the parameters using romraider listed in this spreadsheet. Winzip the logs and PM or email them to me. http://www.romraider.com/forum/topic1871.html Link to comment Share on other sites More sharing options...
mickeyd2005 Posted January 23, 2009 Share Posted January 23, 2009 I hear you, certainly a valid point with that much A/F trim learned, but why would it run the asked-for AFR for many seconds, then go lean just like a switch? Could it be that I passed some sort of threshold into open loop? I'm also confused how I could be so far off with the intake calibration. I have a K&N Typhoon with an X02 FMIC, and I used the intake cal that was posted up on RomRaider for the same combo. I probably should just stop being lazy and tune the intake... Thanks for your help, Jeremy In one of the other threads, you said you are using Cobb ST. Did you account for the column shift in the MAF table. Note that the first row is shifted over by one cell to account for the cell labeled [Table2D]. This is how we paste 2D tables into Romraider. Link to comment Share on other sites More sharing options...
BlackGT Posted January 23, 2009 Author Share Posted January 23, 2009 Yes, I am using ST, and I did account for the shift in the cells when I copied them. That spreadsheet looks pretty powerful, I'll work at getting it done over the weekend, thanks. Link to comment Share on other sites More sharing options...
BlackGT Posted January 23, 2009 Author Share Posted January 23, 2009 Log the parameters using romraider listed in this spreadsheet. Winzip the logs and PM or email them to me. http://www.romraider.com/forum/topic1871.html I'm looking into the spreadsheet and since I have ST, can I log the parameters listed and send that to you, or is a romraider log required? Also looks like I need to switch back to stock injectors for now. Jeremy Link to comment Share on other sites More sharing options...
mickeyd2005 Posted January 23, 2009 Share Posted January 23, 2009 I'm looking into the spreadsheet and since I have ST, can I log the parameters listed and send that to you, or is a romraider log required? Also looks like I need to switch back to stock injectors for now. Jeremy I didn't know you had non-stock injectors. That could explain the fuel trim issues. I don't know if ST logs are compatible. You can try. The key is to use steady throttle conditions. It could be fast or slow as long as acceleration is steady. Link to comment Share on other sites More sharing options...
bugblatterbeast Posted January 25, 2009 Share Posted January 25, 2009 I don't know if ST logs are compatible. You can try. The key is to use steady throttle conditions. It could be fast or slow as long as acceleration is steady. there is a pretty good chance they are not exactly what you will be looking for. ST logged injector PW include both the latency and some other correction factor. I'm not positive what it is yet but based on my recent experiments I'm suspecting the per-cylinder injector trims. With the 510N calibration ST is based off of there seems to be some unexpected behaviour (haven't had time to really look into it but something is off) Link to comment Share on other sites More sharing options...
BlackGT Posted January 27, 2009 Author Share Posted January 27, 2009 Can I log with RomRaider on a StreetTuner-tuned ECU? Just for a test, I logged at 6 different constant airflows (ranging from 15-55g/sec) with a reset ECU and ended up with less than 2.4% average fuel trim for all of the airflows I logged. Most of them were less than 1.5% average trim. How close should the intake calibration be? are we looking for within 1%? Jeremy Link to comment Share on other sites More sharing options...
mickeyd2005 Posted January 27, 2009 Share Posted January 27, 2009 AFR Learning A, B, and C, I let it go to +-5% unless I plan to install injectors. I then try to get A and C to within +-2%. I always try to get D to within +-2%. What did you change? Your previous AFR Learning D was -12%. Link to comment Share on other sites More sharing options...
BlackGT Posted January 27, 2009 Author Share Posted January 27, 2009 AFR Learning A, B, and C, I let it go to +-5% unless I plan to install injectors. I then try to get A and C to within +-2%. I always try to get D to within +-2%. What did you change? Your previous AFR Learning D was -12%. I changed my injector scalar, I had changed the scalar just based on idle trims before, but that obviously was not accurate. I'm still going to try to get the romraider logs. Jeremy Link to comment Share on other sites More sharing options...
rao Posted January 27, 2009 Share Posted January 27, 2009 http://www.legacygt.com/forums/showthread.php?t=43450& Rob IF YOU CARE ABOUT YOUR CAR YOU SHOULD NEVER DRIVE IT Link to comment Share on other sites More sharing options...
Innovative Tuning Posted January 31, 2009 Share Posted January 31, 2009 Generally that's just what the wideband sees during the shift as a mix of the overrun someone mentioned (no combustion) mixed with some combustion and you read somewhere between free air and normal AFRs. Unless you have your wideband an inch or two from a head port, which would be a bad idea due to the heat there, you aren't going to get a clear enough picture of when there's no combustion and when there's lean combustion in a shifting situation where you're talking about milliseconds of time. On a stock ECU setup if the car runs properly under all conditions, ignoring shifts, your AFRs while shifting are probably really fine. Watching what ignition timing does during shifts is generally far more critical. Also, are you sure 18:1 isn't what your wideband caps lean at? What wideband are you using? I see you have a log labelled steady state lean. Now THAT definitely concerns me, but I can't open either of your logs. Both come up as corrupt. Link to comment Share on other sites More sharing options...
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