mistaben Posted September 7, 2011 Share Posted September 7, 2011 all the INT/BLM values are... close... usually like blms of 126 and ints of 130-133. or like ints of 125 and blms of 129. (i'm guessing that split difference just means the saved memory area at that block is just off... and not the actual VE table itself? or sometimes... it will be dead nuts on, 127/128; 129/128; 128/128; sometimes like 130/127 or so. i am using tuner pro btw, and datalogging it to excell, with a BLM update time of 2.4seconds and an update value of 1. 383, SR, 190cc AFR heads, the LPE 219/219 camshaft, and a 58mm TB (which a bitch to tune!!!), and a set of 30lb injectors... am I getting close? what is the depression in the table from? cam overlap and O2 sensor issues at idle RPMS? or is that an effect of having a (stock) delayed BLM update value 2.4 seconds and just how I am running my test runs? (I am passing the RPM range through from 600 - to about 2000 and repeating the tests over and over.... 58mm TB is TOO big to get it sit at an exact rpm value...) Link to comment Share on other sites More sharing options...
mistaben Posted September 7, 2011 Author Share Posted September 7, 2011 notice the depression in the curve at like 1300-1400rpm and 70kPa? is that from not tuning in that area well enough (it idles at 58-62kPa) or from some kind of cam overlap and over dump of fuel on the O2 sensor issue? Link to comment Share on other sites More sharing options...
MOTV8 Posted September 7, 2011 Share Posted September 7, 2011 Uhh.... Patience. ACEholes Two Snails or NicD may be able to answer your questions. Link to comment Share on other sites More sharing options...
Ted Y Posted September 7, 2011 Share Posted September 7, 2011 I concur. Link to comment Share on other sites More sharing options...
Buccaneer Posted September 7, 2011 Share Posted September 7, 2011 I have a couple questions. What ecm are you using and is it modded and why did you choose TunerPro? I use TunerPro RT for my older 1227747 and 1228746 ecm on my 383 CF and lock the BLM at 128. Are you data logging and then doing a "Learn"? If so, stop. You only need to do that until you get you close and then do the rest on a dyno, not the street. If you continue to do "Learns" after a datalog it will learn the decell side as well and give you the valleys you see now in the VE table vs a more rounded tapered VE. LPM has the perfect dyno for doing this type of tuning when it gets back into the shop. Good luck. Link to comment Share on other sites More sharing options...
TheCMSH Posted September 7, 2011 Share Posted September 7, 2011 That one has Parker written all over it. But I sure think the colors are pretty!!!! Link to comment Share on other sites More sharing options...
NicD Posted September 7, 2011 Share Posted September 7, 2011 Well, with your fuel trims being so close to 0 (128) I'm going to say it's accurate and it's real. It's not uncommon to have flatter spots and dips in VE tables with aftermarket camshafts. As a comparison on LS motors you will more often find dips around 3k-4k with bigger camshafts and 2400-2800 will be virtually the same if not dipping at 2400 also. It's not an overlap issue so to speak, it's just the nature of the camshaft and it's timing events. You always give up something to gain something with camshafts so it's nothing to be alarmed about. Besides, at that low of an RPM and high of a MAP reading it's easily hit on the street with both of your feet working the pedals and you should get accurate data within seconds even on the older slower PCMs. The whole load bearing dyno is the only way to tune myth is just that and about the only time I have had better luck with one is with turbo vehicles. Besides just about every dyno out there has brakes which can be used to simulate that same function if necessary. Then again histograms in a scan tool tell the story much more easily on the newer vehicles as well so take it for what it's worth. Link to comment Share on other sites More sharing options...
mistaben Posted September 7, 2011 Author Share Posted September 7, 2011 I have a couple questions. What ecm are you using and is it modded and why did you choose TunerPro? I use TunerPro RT for my older 1227747 and 1228746 ecm on my 383 CF and lock the BLM at 128. Are you data logging and then doing a "Learn"? If so, stop. You only need to do that until you get you close and then do the rest on a dyno, not the street. If you continue to do "Learns" after a datalog it will learn the decell side as well and give you the valleys you see now in the VE table vs a more rounded tapered VE. LPM has the perfect dyno for doing this type of tuning when it gets back into the shop. Good luck. I am using the stock 7727 pcm if that is what you mean? I am however using the 7730 definition file from the 90-91 F bodies, because quite frankly it is the only definition file out there on the webs that I could find and every one say it works for the 7727 Y bodies and it seems to be working and reading correctly honestly. I chose tunerpro because it came with the autoprom package and, it seems at least, to do everything I need it too? - was there a better software set to use? - I posted a post earlier on how to use tunerpro to read, log, burm and emulate new proms for this a few days ago I think. no, I am datalogging THE learn that the pcm does, and using the learn to modify the volumetric efficiency tables in the prom. I am not understanding what you mean by datalogging the decel side as well? are you saying the car has two sets of AFR's one for accel and decel? - I have the power enrichment mode turned off completely at the moment. so it isn't even logging the accel side, I am just trying to tune the VE table so it is semi accurate. - I don't know if there is a way to tune//turn off a decel calculator in the pcm. I will take a close look though, that is a very good idea. thankyou. and I don't know about the dyno tuning lol... I am starting to run out of money and i have already spent 450$ in tools and software and don't feel like spending another 700$ to pay someone to tune it. that would be a 1200$ tune. :/ Link to comment Share on other sites More sharing options...
mistaben Posted September 7, 2011 Author Share Posted September 7, 2011 Well, with your fuel trims being so close to 0 (128) I'm going to say it's accurate and it's real. It's not uncommon to have flatter spots and dips in VE tables with aftermarket camshafts. As a comparison on LS motors you will more often find dips around 3k-4k with bigger camshafts and 2400-2800 will be virtually the same if not dipping at 2400 also. It's not an overlap issue so to speak, it's just the nature of the camshaft and it's timing events. You always give up something to gain something with camshafts so it's nothing to be alarmed about. Besides, at that low of an RPM and high of a MAP reading it's easily hit on the street with both of your feet working the pedals and you should get accurate data within seconds even on the older slower PCMs. The whole load bearing dyno is the only way to tune myth is just that and about the only time I have had better luck with one is with turbo vehicles. Besides just about every dyno out there has brakes which can be used to simulate that same function if necessary. Then again histograms in a scan tool tell the story much more easily on the newer vehicles as well so take it for what it's worth. i will have to make a note to do that one foot on each some more... was doing that a bit a few days ago. not today on my last datalogging event. *sighs* one more detail I forgot lol.... ... thanks to everyone for chiming in so far! Link to comment Share on other sites More sharing options...
mistaben Posted September 7, 2011 Author Share Posted September 7, 2011 I have a couple questions. What ecm are you using and is it modded and why did you choose TunerPro? I use TunerPro RT for my older 1227747 and 1228746 ecm on my 383 CF and lock the BLM at 128. Are you data logging and then doing a "Learn"? If so, stop. You only need to do that until you get you close and then do the rest on a dyno, not the street. If you continue to do "Learns" after a datalog it will learn the decell side as well and give you the valleys you see now in the VE table vs a more rounded tapered VE. LPM has the perfect dyno for doing this type of tuning when it gets back into the shop. Good luck. as a matter of fact yes there is some kind of fuel cut off on deceleration... fuel cut off deceleration disable engine speed fuel cut off deceleration disable MAP fuel cut off deceleration enable MAP fuel cut off deceleration enable max engine speed fuel cut off deceleration min time between cut offs fuel cut off engine speed fuel cut off min temp fuel cut off min time fuel cut off min vehicle speed do you think these options are giving me my depressions? that would make sense... i will have to start taking only the datalogs that are on acceleration than through those RPM points.. can I shut off the deceleration cut off and go take a datalogging of it to get some good excel data and average out the points to get the VE table correct, then reenable it when finished? ... or are you saying I should take the chip out to reset the BLM's, and then plug it back in and do a quick datalog to tune it correctly? i'm a little confused on your suggestion but i like the idea Link to comment Share on other sites More sharing options...
Buccaneer Posted September 7, 2011 Share Posted September 7, 2011 After reading the comments, I think I'll just stay out of this. Good luck on your tune whichever dyno you choose. Link to comment Share on other sites More sharing options...
mistaben Posted September 7, 2011 Author Share Posted September 7, 2011 I have a couple questions. What ecm are you using and is it modded and why did you choose TunerPro? I use TunerPro RT for my older 1227747 and 1228746 ecm on my 383 CF and lock the BLM at 128. Are you data logging and then doing a "Learn"? If so, stop. You only need to do that until you get you close and then do the rest on a dyno, not the street. If you continue to do "Learns" after a datalog it will learn the decell side as well and give you the valleys you see now in the VE table vs a more rounded tapered VE. LPM has the perfect dyno for doing this type of tuning when it gets back into the shop. Good luck. as a matter of fact yes there is some kind of fuel cut off on deceleration... and for that chip it is set between 1100 and 1400 rpms... so i need to pull out the fuel cut off.. (ill read the anht_hac on how to do that, unless you know which way these options go off top of your head?)... and then go out and re-datalog and excel it. Link to comment Share on other sites More sharing options...
Border Vette Posted September 8, 2011 Share Posted September 8, 2011 I concur. Link to comment Share on other sites More sharing options...
old yeller Posted September 9, 2011 Share Posted September 9, 2011 I concur. Link to comment Share on other sites More sharing options...
C4orce2 Posted September 9, 2011 Share Posted September 9, 2011 I have to admit that I don't know what the hell you guys are talking about most of the time in this thread. That's why I just pay someone else, much smarter than me, to do everything on my car. I just drive it and enjoy it and do as little actual work on it as I can. I guess I'm just too old to study and learn this stuff now. Link to comment Share on other sites More sharing options...
mistaben Posted September 12, 2011 Author Share Posted September 12, 2011 so some of you guys actually think that is legitimate camshaft shape and not something caused from the fuel cut off during deceleration at that RPM? - I haven't had time to run new datalogs yet. had to take a few days to fight with gf, and I have sprung a coolant leak. it doesn't appear to be in the oil, tomorrow I will pull the spark plugs and turn the motor over to see if it leaked into the engine. if it isn't there..... I will wash the whole engine bay out (it is reall really dirty) and find where my oil leak and coolant leak is. and pull apart top half of the block and redo the gaskets.... after that I will be back to trying to tune it. will have to make a set of datalogs without the fuel cut off enabled and see how the excel data looks. thanks all for your replys. I have to admit that I don't know what the hell you guys are talking about most of the time in this thread. That's why I just pay someone else, much smarter than me, to do everything on my car. I just drive it and enjoy it and do as little actual work on it as I can. I guess I'm just too old to study and learn this stuff now. /knowthatfeelbro Link to comment Share on other sites More sharing options...
NicD Posted September 12, 2011 Share Posted September 12, 2011 so some of you guys actually think that is legitimate camshaft shape and not something caused from the fuel cut off during deceleration at that RPM? If you are referring to the dip that you were talking about before (the depression in the curve at like 1300-1400rpm and 70kPa) then it's definitely not fuel cut. The MAP is reading far too high and is nowhere near where dfco will turn on. after that I will be back to trying to tune it. will have to make a set of datalogs without the fuel cut off enabled and see how the excel data looks. It's always a good idea to disable it temporarily but it's only going to kick in during high vacuum and no throttle for the most part so it's also very easy to mentally look at the logs and filter it. Link to comment Share on other sites More sharing options...
Two Fangs Posted November 5, 2011 Share Posted November 5, 2011 I can't believe I missed this thread. Link to comment Share on other sites More sharing options...
FNBADAZ06 Posted November 5, 2011 Share Posted November 5, 2011 I can't believe I missed this thread. I was suprised when you didn't offer your thoughts when this was posted some weeks ago....it got lost in the original "tech" section Link to comment Share on other sites More sharing options...
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