rc0032 Posted August 21, 2007 Share Posted August 21, 2007 ^ yes and it was a bad discussion The range isn't big enough to be a true WB. Just go get one. Link to comment Share on other sites More sharing options...
bugblatterbeast Posted August 21, 2007 Share Posted August 21, 2007 I see. I do have a WBO2. I was just curious to see if anyone had tried CL targeting all the time. Most of my data logs have the two sensors in agreement, so long as the pressure in the manifold is low. When the exhaust pressure is high, the stock sensor reads extra rich (as expected). My hope was that it would be possible to eliminate discontinuities when transitioning from CL to OL. I've been carefully adjusting the primary fuel maps to match the OL/CL transition points. The method works but is tedious. I was hoping to find a short cut... Link to comment Share on other sites More sharing options...
BobGT Posted August 31, 2007 Share Posted August 31, 2007 I've found that I can get very good economy with 0 AVCS and a bunch of advance OR moderate AVCS and much less advance (~5 deg less). My running theory is that the 0 AVCS setting is self EGRing and the extra timing is needed because of the charge dilution whereas the moderate AVCS point has better VE and compression. So far the economy peak is at 6.8L/100km at 105 kph Your theory is right. Some degree of retard is built in cams (I believe somebody from Cobb - Cristian maybe, was explaining how AVCS works - can't find link right now). Bob Link to comment Share on other sites More sharing options...
SeeeeeYa Posted August 31, 2007 Share Posted August 31, 2007 The best discussion about AVCS I've yet found ends here: http://forums.nasioc.com/forums/showthread.php?t=1078290&page=12 But go to the beginning to read it all. The link above reveals what I personally came away with that I use to chase answers to my own AVCS questions. Link to comment Share on other sites More sharing options...
bugblatterbeast Posted August 31, 2007 Share Posted August 31, 2007 The best discussion about AVCS I've yet found ends here: http://forums.nasioc.com/forums/showthread.php?t=1078290&page=12 But go to the beginning to read it all. The link above reveals what I personally came away with that I use to chase answers to my own AVCS questions. Edmundu passed some words of wisdom to me a while back about AVCS.... To put it simply, don't spend too much time dialing it in on the dyno. You will get some gains with the first few adjustments, then the returns get smaller quickly. You can spend a lot of money on dyno time trying to get the absolute best AVCS map and find that you were chasing a shadow because you didn't account for all the confounding influences during the test. Just get it close, then back it out a little. You go downhill real fast with a little too much AVCS. Link to comment Share on other sites More sharing options...
SeeeeeYa Posted August 31, 2007 Share Posted August 31, 2007 Edmundu passed some words of wisdom to me a while back about AVCS.... To put it simply, don't spend too much time dialing it in on the dyno. You will get some gains with the first few adjustments, then the returns get smaller quickly. You can spend a lot of money on dyno time trying to get the absolute best AVCS map and find that you were chasing a shadow because you didn't account for all the confounding influences during the test. Just get it close, then back it out a little. You go downhill real fast with a little too much AVCS. It has been edmundu, almost exclusively, that has provided whatever help I've gotten so far. His input to me about AVCS was similar and coupled with what I've learned elsewhere confirms that AVCS is a tuning tree with little fruit. I still want some of that fruit, however. Link to comment Share on other sites More sharing options...
rao Posted August 31, 2007 Author Share Posted August 31, 2007 Yep, There is almost no real gain over the Cobb Statge 2 AVCS tables. No one asked me, I could have saved you some trouble, if you would have believed me Rob IF YOU CARE ABOUT YOUR CAR YOU SHOULD NEVER DRIVE IT Link to comment Share on other sites More sharing options...
SeeeeeYa Posted August 31, 2007 Share Posted August 31, 2007 Yep, There is almost no real gain over the Cobb Statge 2 AVCS tables. No one asked me, I could have saved you some trouble, if you would have believed me Well, like I said, for however well I have done in the past, shortly I will have some serious tuning to do. With a new AVO turbo, and new injectors and pump coming, things get more serious. I have a lot to learn in the next few weeks and any help would be appreciated. ST already has some words on the Deatschwerks, but I'm sure individual experiences flesh them out. Otherwise I have no idea what to do about a pump, if anything, and most certainly not a turbo. I have a lot of reading to do. My VF40 has given its all. Reinforcements are on the way. I'm listening...... Link to comment Share on other sites More sharing options...
LittleBlueGT Posted August 31, 2007 Share Posted August 31, 2007 It has been edmundu, almost exclusively, that has provided whatever help I've gotten so far. His input to me about AVCS was similar and coupled with what I've learned elsewhere confirms that AVCS is a tuning tree with little fruit. I still want some of that fruit, however. I was told by Edmundu that cranking the AVCS table up to 40 in all load cells above about 1.8g (except the bottom row) is what was done when he was on the dyno to help get a couple hundred rpm of spool out of it. I tried that and it worked. Since then I have tweaked things a bit. It definitely has helped, vs what COBB stage2 AVCS are. Have you guys read this thread from enginuity? It seems to show the possibility for significant gains with high AVCS values before and during initial turbo spool. (enginuity site not working for me now, I will post up link later) 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...
bugblatterbeast Posted August 31, 2007 Share Posted August 31, 2007 wow, that's a lot of AVCS. On the dyno I found that you could spool sooner with high avcs but there was a point where you were making less torque. the boost pressure would come up quickly but there was no flow, I'm guessing that the excessive overlap was exposing the intake to the exhaust backpressure. Link to comment Share on other sites More sharing options...
LittleBlueGT Posted August 31, 2007 Share Posted August 31, 2007 This was the thread: http://www.enginuity.org/viewtopic.php?p=12254#12254 There is a definite limit to what AVCS can do, too much hurts air-flow, although it causes higher boost to increased back pressure in the system. If you look at edmundu's dyno charts you will see he made more power (not necessarily more boost) with higher advanced AVCS at lower rpm. 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...
rc0032 Posted September 4, 2007 Share Posted September 4, 2007 bump for Edmunds comments. Link to comment Share on other sites More sharing options...
Legacy_GT_Pilot Posted September 5, 2007 Share Posted September 5, 2007 (edited) My current tune (as done by my tuner) has the stock AVCS table settings. I'm not about to try and get the most out of this table, but would like to just take the Cobb Stage 2 settings and apply them to my map. Is this a good idea seeing how I've got an upgraded turbo and other goodies or just plain stupid? Dave ________ Bmw M88 Edited April 22, 2011 by Legacy_GT_Pilot Link to comment Share on other sites More sharing options...
boostsr20 Posted September 5, 2007 Share Posted September 5, 2007 My TDC map had the AVCS set to 38 from .7 to 2.2 load wise and up to about 2400 RPMs. What load cells and up to what RPM are you running 40 in? EDIT: Also, should the AVCS tables be scaled out to higher loads? Link to comment Share on other sites More sharing options...
edmundu Posted September 5, 2007 Share Posted September 5, 2007 My current tune (as done by my tuner) has the stock AVCS table settings. I'm not about to try and get the most out of this table, but would like to just take the Cobb Stage 2 settings and apply them to my map. Is this a good idea seeing how I've got an upgraded turbo and other goodies or just plain stupid? Dave Really it depends on what the tuner did with the Primary Ign tables in the affected cells. Generally speaking, you need LESS timing if you add AVCS timing in. It is something you can add upon little by little to see when you need to make adjustments, or just leave it alone.....especially with anything smaller than a 20g turbo. Even then there aren't that many gains to be had. Link to comment Share on other sites More sharing options...
edmundu Posted September 5, 2007 Share Posted September 5, 2007 bump for Edmunds comments. Yes, I did crank my AVCS to 40 from 1.2 load & up across the board up til the 3.6k area, then it was stepped down to zero. It did create more trq about 200 rpm earlier than my previous AVCS which was a little above the Cobb values. On the dyno, it doesn't generate the same amount of load seen on the real pavement, and especially with these bigger turbo's. On my way home that night, I started getting that dreaded driveline shudder in 4-5th gears, under heavy load in the 2.9-3.7k rpm band. I started dropping AVCS timing a little at a time, til it resolved it completely! I think my avcs peaks somewhere around 32, and tapers to 0. I rather lose a bit of trq, then to find out just how much trq that driveshaft carrier can handle;). Like it has been said, there are some gains to be had, but it isn't all that much, and you needn't spend a ton of time on it. Perfect your fuel/timing/boost curves instead. Link to comment Share on other sites More sharing options...
2005garnetGT Posted September 5, 2007 Share Posted September 5, 2007 does anyone actually know the limit of cam advance possible using the USDM cam setup? boostsr20 had 38 degrees of AVCS and I was under the impression (as were a lot of people in that enginuity thread) that ~30 was the max our cam gears could do Link to comment Share on other sites More sharing options...
boostsr20 Posted September 5, 2007 Share Posted September 5, 2007 does anyone actually know the limit of cam advance possible using the USDM cam setup? boostsr20 had 38 degrees of AVCS and I was under the impression (as were a lot of people in that enginuity thread) that ~30 was the max our cam gears could do Just to clarify, thats what TDC had the map set for. I didn't datalog it that high. I have it dropped back significanly now. Link to comment Share on other sites More sharing options...
2005garnetGT Posted September 5, 2007 Share Posted September 5, 2007 edmund, have you actually logged the position of the cam to see if it ever got advanced that far? Link to comment Share on other sites More sharing options...
BigHonu Posted September 5, 2007 Share Posted September 5, 2007 I have mine set at 30 with logs indicating that they top out at 31 sometimes. I have not tried setting it higer than that. I think LBGT mentioned something in the 40's. Link to comment Share on other sites More sharing options...
bugblatterbeast Posted September 5, 2007 Share Posted September 5, 2007 I peak around 30 with my setup. Much above that, I go backwards. My exhaust backpressure is just too high... Link to comment Share on other sites More sharing options...
LittleBlueGT Posted September 5, 2007 Share Posted September 5, 2007 I have mine set at 30 with logs indicating that they top out at 31 sometimes. I have not tried setting it higer than that. I think LBGT mentioned something in the 40's. I have logged 46 degrees advance. 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...
LittleBlueGT Posted September 14, 2007 Share Posted September 14, 2007 Here are all the tables in ST advanced: I don't think they have been put up before. 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...
sgt Posted September 14, 2007 Share Posted September 14, 2007 any added datalogging functionality? Link to comment Share on other sites More sharing options...
LittleBlueGT Posted September 14, 2007 Share Posted September 14, 2007 any added datalogging functionality? I will check, likely tomorrow. 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...
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