Speed Density Tuning
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From: Marysville, WA
Speed Density Tuning Oh what fun that $hit is! No, REALLY!!! 
While I admit Bill & I did make some very good progress with my car, it became pretty clear to me that there are tables in there that control stuff that either are hidden, or named wrong. Every once in a while, things we just fixed would seem to revert back, evne tho the tables were where we set them.
Anyway, it took us about 1/2 hr of fiddling to get the car to idle after disconnecting the MAF. After that it took about 5 seconds to realise how far off my tune was. One end of the cells were reading -18, the other end was at +20. (limits are +/-25 for those that don't know)
So we made some revisions, drove the car, made more revisions, drove some more, etc etc etc for 8 stinkin hours! And like I said, we made some dramatic improvements, and learned a couple things too. Now if only I can find what makes the timing dip down by 7-10* while idling, I think everything will be all better.
I'll have to show you the before & after tunes Ellis. You will be surprised how far off I had my tune. And how much timing the car actually likes at idle.
Thank you Bill for spending that much time on my car!
While I admit Bill & I did make some very good progress with my car, it became pretty clear to me that there are tables in there that control stuff that either are hidden, or named wrong. Every once in a while, things we just fixed would seem to revert back, evne tho the tables were where we set them.Anyway, it took us about 1/2 hr of fiddling to get the car to idle after disconnecting the MAF. After that it took about 5 seconds to realise how far off my tune was. One end of the cells were reading -18, the other end was at +20. (limits are +/-25 for those that don't know)
So we made some revisions, drove the car, made more revisions, drove some more, etc etc etc for 8 stinkin hours! And like I said, we made some dramatic improvements, and learned a couple things too. Now if only I can find what makes the timing dip down by 7-10* while idling, I think everything will be all better.
I'll have to show you the before & after tunes Ellis. You will be surprised how far off I had my tune. And how much timing the car actually likes at idle.
Thank you Bill for spending that much time on my car!
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From: LT1 land...the "409" of the 90s!
Nice. I am still waiting on my Wide band so I have not even tried at this point. I have a feeling the timing issue is what I am fighting on Tom's car. as long as you let it idle down after you start it the car is fine. If you crank it up and just toss it in gear you have a fight on your hands to keep the car running. Out of all the Idles table there are only two so far that seem to really have an effect on any thing.
Over all there are to many tables that do not do much and not enough that do what we need
One that comes to mind is the "Cruise control" issue. thought we had it but then the car would not start rite. get the car to start right and it is back. there HAS to be a table that controls either target Gm/ps Vs MPH or IAC counts Vs MPH at 0% TPS.
I am making a call this morning to see what we can find
I may even call you and BS
I am tired of two things. First waiting my Dynojet to build my wide band and ships it and two LS1s that won't idle. the tunning section is full of them!
BTW do not feel bad. we have about 16 hours in this one on just base tune and Idle!
Over all there are to many tables that do not do much and not enough that do what we need
One that comes to mind is the "Cruise control" issue. thought we had it but then the car would not start rite. get the car to start right and it is back. there HAS to be a table that controls either target Gm/ps Vs MPH or IAC counts Vs MPH at 0% TPS.I am making a call this morning to see what we can find
I may even call you and BS
I am tired of two things. First waiting my Dynojet to build my wide band and ships it and two LS1s that won't idle. the tunning section is full of them!
BTW do not feel bad. we have about 16 hours in this one on just base tune and Idle!
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From: LaConner WA
It was my pleasure Mark. We both learned alot and that's what it's all about. I don't remember what we changed to cure the idle timing sag but we had that puppy nailed for at least several hours 
By the time the problem popped back up I think that we both were tired of thinking lol ! If we hadn't been fighting the idle timing issue for so long we probably would've had time to start scaling your MAF, which is something I haven't tried yet so was looking forward to practicing on YOUR car haha ! anyway like you said we made some big progress. One more day of tuning and I think 95% of the tuning will be done. It IS some time consuming ****, but I love this stuff haha !
By the time the problem popped back up I think that we both were tired of thinking lol ! If we hadn't been fighting the idle timing issue for so long we probably would've had time to start scaling your MAF, which is something I haven't tried yet so was looking forward to practicing on YOUR car haha ! anyway like you said we made some big progress. One more day of tuning and I think 95% of the tuning will be done. It IS some time consuming ****, but I love this stuff haha ! TECH Addict
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From: LaConner WA
Originally Posted by WAHUSKER
It might run stronger Jason, but with a cam, stall & automatic it won't idle & dies when you pull it into gear. (like Ellis was saying)
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From: Marysville, WA
We should hook up with Ellis & compare notes. He's been fighting the same issue. Between you, me, him & Jimbob we should be able to redesign the wheel.
Oh, and we tried a couple of Another Users ideas. Like Idle Proportional to "off", and it had no affect. What seemed to help most was setting the timing in the idle area to 30*+. But then we screwed that up too.
I wish we'd have had tiome to hook up the wide band sensor & do some WOT tuning. Next time maybe....
Oh, and we tried a couple of Another Users ideas. Like Idle Proportional to "off", and it had no affect. What seemed to help most was setting the timing in the idle area to 30*+. But then we screwed that up too.
I wish we'd have had tiome to hook up the wide band sensor & do some WOT tuning. Next time maybe....
Last edited by WAHUSKER; May 2, 2005 at 11:13 AM.
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When hell freezes over and my car gets finished I would really like to go the speed density route. But from the sounds of the problems you guys are having I am not sure I want to hassle with it. I have heard of how hard it is to tune the cam I am running WITH a MAF, I would hate to see it WITHOUT the MAF.
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From: LaConner WA
Originally Posted by NataSS Inc
When hell freezes over and my car gets finished I would really like to go the speed density route. But from the sounds of the problems you guys are having I am not sure I want to hassle with it. I have heard of how hard it is to tune the cam I am running WITH a MAF, I would hate to see it WITHOUT the MAF.
As a side note, the bigger the cam you have, the more likely it is that your car will run better without a MAF. Supposedly getting them to idle and accept part throttle input is much easier MAFless. I've been running my car MAFless for the last 3 weeks since my laptop is in the shop and it's almost undrivable with the MAF plugged in. I wasn't able to do any rescaling at all before my laptop went "POOF" so for now MAFless it is 
. It runs fine. Idle/part throttle/WOT etc. I AM going to rescale my MAF anyway when I get my laptop back, and at that point I'll decide whether MAFless is better for my car or not. I have a feeling that your car will be MAFless only 
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From: norfolk va
Originally Posted by WAHUSKER
We should hook up with Ellis & compare notes. He's been fighting the same issue. Between you, me, him & Jimbob we should be able to redesign the wheel.
Oh, and we tried a couple of Another Users ideas. Like Idle Proportional to "off", and it had no affect. What seemed to help most was setting the timing in the idle area to 30*+. But then we screwed that up too.
I wish we'd have had tiome to hook up the wide band sensor & do some WOT tuning. Next time maybe....
Oh, and we tried a couple of Another Users ideas. Like Idle Proportional to "off", and it had no affect. What seemed to help most was setting the timing in the idle area to 30*+. But then we screwed that up too.
I wish we'd have had tiome to hook up the wide band sensor & do some WOT tuning. Next time maybe....
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From: Moxee
Originally Posted by sardog46
Mybee set up some dyno time so we can get them all nailed down at the same time.
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From: Marysville, WA
Oh, one tidbit I left out that made Bill happy. To show both the tune's VE Table & the Histogram Log at the same time (to compare cells for revising) open both & then right click on the tool bar at the bottom of your Window & select Tile Horizontally (or Vertically, whichever you prefer). You can do this with all Windows programs.....
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From: Fredericksburg, VA
Welcome to the wonderful world of SD tuning Mark! Just keep at it- when everything starts coming together you'll be amazed at how nice your car will be running. I've got my Torquer idling rock solid at 800 RPM, and my VE table is so spot on I'm running with my LTFT's disabled, and my STFT's are all between +/- 3. It takes some time, but the end result is worth it.
As far as tuning the VE table goes, stop using LTFT's as soon as you can. They take forever to learn, and are useless for tuning the higher RPM VE cells. Once you get your LTFT's within the +/- 10 or 15 range, diasable them and use your STFT's instead. You will get much quicker and much more accurate results. I actually wrote up a "VE tuning using fuel trims" how-to that made it into the sticky at the top of the PCM section here. It goes into detail on not just the hows, but also the whys, and I describe the procedure I used to tune my VE table using mostly STFT's. Using that method you should be able to go from a stock VE table to one that is pretty close to perfect in a few hours.
Could you go into a little bit more detail about idle problems you've been having? Maybe I could throw a few ideas your way.
As far as tuning the VE table goes, stop using LTFT's as soon as you can. They take forever to learn, and are useless for tuning the higher RPM VE cells. Once you get your LTFT's within the +/- 10 or 15 range, diasable them and use your STFT's instead. You will get much quicker and much more accurate results. I actually wrote up a "VE tuning using fuel trims" how-to that made it into the sticky at the top of the PCM section here. It goes into detail on not just the hows, but also the whys, and I describe the procedure I used to tune my VE table using mostly STFT's. Using that method you should be able to go from a stock VE table to one that is pretty close to perfect in a few hours.
Could you go into a little bit more detail about idle problems you've been having? Maybe I could throw a few ideas your way.
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From: Marysville, WA
OK Matt, so basically what happens it it runs down the road fine now. Got pretty much all the cells to be 0 to -10. But when you first start it, it does that famous cam hunt-for-idle crap. Wish I had a $ for all the times I've thought I fixed it. It surges from 500 to 1500 rpm, and if left alone will die. Does the same thing if you drive to the store, go inside & buy beer, come back out, same ****.
Anyway, all the cells dance around while it's doing this, and when it gets over to the lowest rpm cells, the timing drops about 10* below what we have EVERY table set to. Bill even tried setting timing to solid 32* while it was running. No affect. And we tried everything. Idle Porportional off, zeroed out the Over & Underspeed Idle timing tables, etc & can't seem to make that go away. We did not try turning the DFCO off because we thought that was for decelerating while driving.
I'm going out now to look at the IAC counts (if I can remember how) to see if they are around 20-30 like Ellis thinks they should be. I know there is some table that screws with the idls settings for the 1st 1-2 minutes after start. And like Bill said, we 'fixed this once', but it's back now. Or it was before I plugged the MAF back in. That seemed to clear it up some. Not sure if it's actually gone tho. I will find out shortly....
Anyway, all the cells dance around while it's doing this, and when it gets over to the lowest rpm cells, the timing drops about 10* below what we have EVERY table set to. Bill even tried setting timing to solid 32* while it was running. No affect. And we tried everything. Idle Porportional off, zeroed out the Over & Underspeed Idle timing tables, etc & can't seem to make that go away. We did not try turning the DFCO off because we thought that was for decelerating while driving.
I'm going out now to look at the IAC counts (if I can remember how) to see if they are around 20-30 like Ellis thinks they should be. I know there is some table that screws with the idls settings for the 1st 1-2 minutes after start. And like Bill said, we 'fixed this once', but it's back now. Or it was before I plugged the MAF back in. That seemed to clear it up some. Not sure if it's actually gone tho. I will find out shortly....
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From: Fredericksburg, VA
Originally Posted by WAHUSKER
OK Matt, so basically what happens it it runs down the road fine now. Got pretty much all the cells to be 0 to -10. But when you first start it, it does that famous cam hunt-for-idle crap. Wish I had a $ for all the times I've thought I fixed it. It surges from 500 to 1500 rpm, and if left alone will die. Does the same thing if you drive to the store, go inside & buy beer, come back out, same ****.
Anyway, all the cells dance around while it's doing this, and when it gets over to the lowest rpm cells, the timing drops about 10* below what we have EVERY table set to. Bill even tried setting timing to solid 32* while it was running. No affect. And we tried everything. Idle Porportional off, zeroed out the Over & Underspeed Idle timing tables, etc & can't seem to make that go away. We did not try turning the DFCO off because we thought that was for decelerating while driving.
I'm going out now to look at the IAC counts (if I can remember how) to see if they are around 20-30 like Ellis thinks they should be. I know there is some table that screws with the idls settings for the 1st 1-2 minutes after start. And like Bill said, we 'fixed this once', but it's back now. Or it was before I plugged the MAF back in. That seemed to clear it up some. Not sure if it's actually gone tho. I will find out shortly....
Anyway, all the cells dance around while it's doing this, and when it gets over to the lowest rpm cells, the timing drops about 10* below what we have EVERY table set to. Bill even tried setting timing to solid 32* while it was running. No affect. And we tried everything. Idle Porportional off, zeroed out the Over & Underspeed Idle timing tables, etc & can't seem to make that go away. We did not try turning the DFCO off because we thought that was for decelerating while driving.
I'm going out now to look at the IAC counts (if I can remember how) to see if they are around 20-30 like Ellis thinks they should be. I know there is some table that screws with the idls settings for the 1st 1-2 minutes after start. And like Bill said, we 'fixed this once', but it's back now. Or it was before I plugged the MAF back in. That seemed to clear it up some. Not sure if it's actually gone tho. I will find out shortly....
If you want, you can forward me your bin file ( bluetorp@yahoo.com ) and I'll see if anything jumps out at me.
Let us know what your LTIT's/STIT's/IAC counts are.
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From: Moxee, WA
Originally Posted by WAHUSKER
What does that mean?