weitek Posted July 15, 2009 Share Posted July 15, 2009 When you say roughness, are you referring to knock correction? I wasn't aware there was a logging parameter dealing with "roughness". Our cars like to throw out false knock at low load/rpm. Mine would constantly show feedback/fine knock correction during cruise on the highway, and sometimes when revving the engine in neutral or taking off very lightly from a stop. Even on the stock map. Same with Franz's and several other cars I've worked on. I tried running significantly less timing than stock and it had no effect. I fought with it for the better part of a year before I finally just raised the threshholds to ignore it. I've confirmed with several other experienced tuners (Little Blue GT comes to mind) that this is the correct approach. Since it only happens at very low load/rpm and almost always under vacuum or very very low levels of boost, and there is apparently nothing we can do to prevent it, it's safe/best to just ignore it so the car drives smoother and it doesn't mess with the IAM/learning. If you check your map I think the threshhold is around 1.05 load as that is what I use on Franz and my maps. If you continue to experience any weird knock correction please send me some logs so I can see what it's doing and I'll see what we need to do. Link to comment Share on other sites More sharing options...
Spec B Posted July 15, 2009 Share Posted July 15, 2009 By roughness I mean misfires...RR calls it (I think) "roughness monitor" for each cylinder..it is loggable parameter on the LGTs. It counts misfires in individual cylinders.. Yeah.. the knock events you described are likely just noise...my car gets a ton of it at cruise and low load driving but so far the IAM has not dropped. Link to comment Share on other sites More sharing options...
weitek Posted July 15, 2009 Share Posted July 15, 2009 Hmm cool. I'll have to check if mine does that (if it's an option in RR). I'll let you know. Link to comment Share on other sites More sharing options...
weitek Posted July 15, 2009 Share Posted July 15, 2009 Initial impressions of the new throttle mapping: WOW. I need to tweak the bottom end a bit as it's too sensitive imo, but the mid and top end is amazing. I'm also using a new boost control scheme which I really REALLY like. More about that later. Link to comment Share on other sites More sharing options...
Spec B Posted July 16, 2009 Share Posted July 16, 2009 Did some logging of the latest Rev. - Idle Fuel trim is better -6.25% - I think the scaling on my maf is off due to the cleaning I did on it yesterday, I am running rich by about .5 all the way up. Here is one 2nd and a few 3rd gear logs (sorry for logging MAf/sec): romraiderlog_20090715_222545.csv romraiderlog_20090715_220005.csv romraiderlog_20090715_224302.csv romraiderlog_20090715_224029.csv romraiderlog_20090715_221136.csv Here is a 15 minute cruise: http://www.box.net/shared/h1ejo7rf1n Link to comment Share on other sites More sharing options...
NSFW Posted July 16, 2009 Share Posted July 16, 2009 I'll report back with my findings at 2500. I know the counts stay at zero in cruise but I've never looked at 2500 in neutral prior to this... The results: free revving at 2500 yields occasional misfires on two cylinders - the same two that occasionally misfire when my engine is idling. Never happens when the engine is actually getting work done though. Link to comment Share on other sites More sharing options...
LittleBlueGT Posted July 16, 2009 Share Posted July 16, 2009 What some people do to avoid it messing up open loop fueling is to disable the airflow range 40 g/sec + of fuel trim compensation. The ECU only uses the learned 40+ to adjust in OL. So if the 40..has no correction, your OL fueling will remain intact with no adjustements fromt he ECU. Interesting read guys. I had to comment on this. If you disable the 40+ g/s (or learning range "D") then you could ask for problems. What happens the one time you are out of town and fill up with fuel that is E10 (which can very easily happen)? All of the fuel trims (especially "D") will change to positive, but that also means that your OL stuff will be positive, that is needed to make up for the different gas. Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
NSFW Posted July 16, 2009 Share Posted July 16, 2009 What LBGT said. I've seen that approach described on RomRaider and thought the same thing. Link to comment Share on other sites More sharing options...
weitek Posted July 16, 2009 Share Posted July 16, 2009 Interesting read guys. I had to comment on this. If you disable the 40+ g/s (or learning range "D") then you could ask for problems. What happens the one time you are out of town and fill up with fuel that is E10 (which can very easily happen)? All of the fuel trims (especially "D") will change to positive, but that also means that your OL stuff will be positive, that is needed to make up for the different gas. What about the higher effective octane of the ethanol? It seems like it would at least partially compensate for the difference in total fuel content. I don't think you'd run into any serious problems if your tune was sound. I'm just speculating though. Edit: I've heard ethanol has ~25% less fuel volume vs gasoline. Maybe "volume" isn't the right term but hopefully you know what I mean. And I've also heard it's ~105 octane. So thats ~25% less fuel vs ~13% more octane rating. Although those numbers could vary depending on the fuel.. I've heard some ethanol fuels are rated lower... and most pumps say "up to 10% ethanol" so there's no telling what you'd get. It'd be cool if we could figure out some kind of formula though. Link to comment Share on other sites More sharing options...
weitek Posted July 16, 2009 Share Posted July 16, 2009 I made some pretty radical changes to my map tonight. After seeing how well the DBW stuff worked with more linear mapping I applied the same concept to boost control and tip-in enrichment. I will be flashing and testing tomorrow and hope to have some good results to share. Link to comment Share on other sites More sharing options...
LittleBlueGT Posted July 16, 2009 Share Posted July 16, 2009 What about the higher effective octane of the ethanol? It seems like it would at least partially compensate for the difference in total fuel content. I don't think you'd run into any serious problems if your tune was sound. I'm just speculating though. Edit: I've heard ethanol has ~25% less fuel volume vs gasoline. Maybe "volume" isn't the right term but hopefully you know what I mean. And I've also heard it's ~105 octane. So thats ~25% less fuel vs ~13% more octane rating. Although those numbers could vary depending on the fuel.. I've heard some ethanol fuels are rated lower... and most pumps say "up to 10% ethanol" so there's no telling what you'd get. It'd be cool if we could figure out some kind of formula though. Ethanol definitely is higher octane, but the rest of the gas is lower octane. The 91 (or 93, or whatever rating) is the combined rating of the gas w/ ethanol in it (assuming E10). So, no, the ethanol will not help out in the above situation. The reason learning range "D" affects OL is exactly to compensate in the case of different gas, not just for CL operations, but for all operations. Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
weitek Posted July 16, 2009 Share Posted July 16, 2009 Ethanol definitely is higher octane, but the rest of the gas is lower octane. The 91 (or 93, or whatever rating) is the combined rating of the gas w/ ethanol in it (assuming E10). So, no, the ethanol will not help out in the above situation. The reason learning range "D" affects OL is exactly to compensate in the case of different gas, not just for CL operations, but for all operations. Oh so you're saying if you fill up w/ "93" E10, they factor the E10 in to that rating already? I always figured it was 93 + E10. Are you sure? (Not disagreeing, just checking). I guess it's a good thing I always fill up at the same place, that has 93 w/ no ethanol. Although it won't matter for very much longer since I'm switching to E85 as soon as I have enough money for some injectors w00t! Link to comment Share on other sites More sharing options...
weitek Posted July 16, 2009 Share Posted July 16, 2009 Actually I noticed something weird when I disabled A/F Learning. I zero'd out the +/- part and the ranges. Now when I check Learning View, the 40+ range always says 2.15. However when I log for it, there is no A/F Learning being applied. Kinda weird. Link to comment Share on other sites More sharing options...
LittleBlueGT Posted July 16, 2009 Share Posted July 16, 2009 Oh so you're saying if you fill up w/ "93" E10, they factor the E10 in to that rating already? I always figured it was 93 + E10. Are you sure? (Not disagreeing, just checking). I am sure. Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
weitek Posted July 16, 2009 Share Posted July 16, 2009 Wow that kinda sucks. No wonder it always runs like crap. Link to comment Share on other sites More sharing options...
Th3Franz Posted July 16, 2009 Author Share Posted July 16, 2009 yep, 93 octane is 93 octane. wtb E85... -Franz The end of a Legacy http://www.youtube.com/th3franz Link to comment Share on other sites More sharing options...
biz77 Posted July 16, 2009 Share Posted July 16, 2009 Disabling the D range is great for getting open loop fueling dialed in. Disabling it permenantly is not something I would do. Link to comment Share on other sites More sharing options...
weitek Posted July 16, 2009 Share Posted July 16, 2009 Disabling the D range is great for getting open loop fueling dialed in. Disabling it permenantly is not something I would do. Yep. I'm going to turn it back on now that I've been schooled. Link to comment Share on other sites More sharing options...
LGTspecB1657615261 Posted September 23, 2009 Share Posted September 23, 2009 Good stuff... bumping the old thread. I am going through tuning with Infamous right now and we are also trying to tackle the stutter I get between 2-3k RPM. Its quite severe, acceleration is erratic and jumpy when I am partial throttle in this range. To reproduce I hold at a constant low load and constant low throttle, a slight uphill incline helps. It just stutters off and on through the 2-3k range. Its horrible! What can I log to help track this issue down? It showed up when I was stage II but Infamous got rid of almost all of it. I added 825cc injectors, fuel pump, and TMIC, and with the new base map it came back. Infamous again got rid of most of it, but there is still something slightly there. It is not bad on the 93 octane map, I can live with it. Right now we just started in on the E85 tune and its horrible. It seems worse in the morning on the way to work, possibly because the engine is warming up. I am sure Shamar will tackle this without an issue, he is an awesome tuner. What parameters can I log to help bring this to light? Do you guys think its something to do with the injector scaling / latency, or the MAF scaling, or the front O2 sensor? I want to help Shamar solve this in whatever way I can. All I can really do is get good logs for him to look at, but not sure what I am looking at here.... Thanks Link to comment Share on other sites More sharing options...
LGTspecB1657615261 Posted September 23, 2009 Share Posted September 23, 2009 Ok I just read up on tuning MAF scaling in closed loop, and I am going to try that utility in RR logger. Perhaps that is what is causing my erratic behavior. My MAF scaling in the closed loop MAF V ranges will not effect my open-loop, correct? Link to comment Share on other sites More sharing options...
biz77 Posted September 23, 2009 Share Posted September 23, 2009 Ok I just read up on tuning MAF scaling in closed loop, and I am going to try that utility in RR logger. Perhaps that is what is causing my erratic behavior. My MAF scaling in the closed loop MAF V ranges will not effect my open-loop, correct? Yes and no:) Any change in the relation of MAFv to airflow in the closed loop range will not have a DIRECT effect on your open loop scaling, BUT if your scaling is not correct in the "D" range (whatever it is set for - stock is over 40 g/s up to the transition to open loop) then this correction gets applied to open loop. For example, if your D-range is scaled so that it is causing the ECU to apply a -2.5% correction, this will be a -2.5% correction in the open loop range of over 40 g/s up to ~65 g/s AND the ECU will apply this -2.5% correction to all open loop areas as well. Link to comment Share on other sites More sharing options...
LGTspecB1657615261 Posted September 23, 2009 Share Posted September 23, 2009 Yup, I understand that from what I have read. My 40+ learning is less than 1% steadily so nothing to worry about there. (-0.60 to be exact). My trims are really pretty good, I am wondering how far off my scaling could really be? Perhaps my airflow ranges are not set up good to show the whole picture. I understand that the A/F learning values reported are just a bulk / averaged result of the A/F correction which is all over the place. Perhaps once I look at come A/F correction plots I will see something the A/F learning numbers are not showing. The goal is to get the A/F correction numbers closest to 0 as possible, correct? Or, in realistic terms, the "cluster" of points on the correction plot are around the 0 line. The other theory is that the stutter has nothing to do with my MAF scaling. I guess we shall see.... Link to comment Share on other sites More sharing options...
Guest Posted September 23, 2009 Share Posted September 23, 2009 I bet it's not your MAF scaling. No way. Unless it's totally off, the ECU has so much room for corrections and is pretty good at it, it's not the problem. It must be mechanical or electrical issue. I yet need to trace down mine Link to comment Share on other sites More sharing options...
LGTspecB1657615261 Posted September 23, 2009 Share Posted September 23, 2009 Yea I think my scaling is looking good. Could be slightly better, and probably will be eventually... but nothing here is shouting bad news to me. http://img44.imageshack.us/img44/2545/090923mafvscorr.jpg LV taken after some partial throttle driving.... http://img22.imageshack.us/img22/4586/learningviewss923200953.jpg Link to comment Share on other sites More sharing options...
LGTspecB1657615261 Posted September 24, 2009 Share Posted September 24, 2009 Replaced my BOV for the heck of it, had a stocker sitting around. That did not do anything. Link to comment Share on other sites More sharing options...
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