When converting to a SD tune
When converting to a SD tune ive been having part throttle issues with my MAF tune for awhile and can’t seem to figure it out. When I unplug the MAF sensor the car runs perfect w/exception of being way too lean at wot. I’ve decided to just convert to a 2 bar SD tune with a 2.5 bar map sensor from dpe corvettes. I’m going to completely take the MAF sensor off the car and just put a straight pipe in place since I have a separate IAT sensor. My question is, how much of your original MAF tune do you just copy and paste the tables into the SD tune to get the car running? Is it only the VE table up to 105kpa or is there other tables that should be used as well? Also, how much of the new SD tune can you change around before doing a “write entire” or does it not matter? I’m scared of bricking my pcm after reading about others. I am extremely new to tuning and using HP Tuners. Thanks in advance!
ideally the VE was pretty close, so you can just C&P it in and start scaling up the 100+ kPa cells
maybe find a similar combo and copy those cells over until you can tune the VE
You'll very much want to pull the spark out of the last two rows of the main table (unify both the hi & lo octane tables) I usually take them down to around 11º through peak torque on pump gas w/no meth.
I do a write entire only when changing OS's completely or altering platform specific stuff. There really is no upper limit to the number of flashes. Just be sure your battery is full in both your laptop and your car. all accessories off & laptop not plugged into the wall outlet.
maybe find a similar combo and copy those cells over until you can tune the VE
You'll very much want to pull the spark out of the last two rows of the main table (unify both the hi & lo octane tables) I usually take them down to around 11º through peak torque on pump gas w/no meth.
I do a write entire only when changing OS's completely or altering platform specific stuff. There really is no upper limit to the number of flashes. Just be sure your battery is full in both your laptop and your car. all accessories off & laptop not plugged into the wall outlet.
also some more notes since I have been doing some canned tunes for my youtube bros.
I put the maf high fail hz at the lowest cell on the table, usually 1500hz. then in the 1500hz and the adjacent cell i put 50lb/hr so the car will fire, idle and then fail the maf ----thanks to darth for that one.
turn off all fuel trims and disable burst knock.
i think thats all i got right off the top of my head
I put the maf high fail hz at the lowest cell on the table, usually 1500hz. then in the 1500hz and the adjacent cell i put 50lb/hr so the car will fire, idle and then fail the maf ----thanks to darth for that one.
turn off all fuel trims and disable burst knock.
i think thats all i got right off the top of my head
Turn off the the short and long term fuel trims and disable knock, just til I get the tables filled correctly? Or permanently since it’s SD? Sorry I’m a noob. Thanks for the info!
I run my turbo truck with stft on and narrowbands. it's great. It especially handy for running gas/corn blends. but I also have done a couple swaps with no trims and they drive just fine.
yes you want the trims off while you tune the VE. I forgot to add to disable the DFCO
are you familiar with the commanded versus observed afr histogram?
I misspeak in a couple places ( you want to multiply by, not add to) but here's a vid I made awhile back.
no sweat on being new to tuning. no one is born knowing any of this. I was in your same shoes once, and I dont consider myself a computer person. But since i have started I've found that tuning is one of the more enjoyable parts of hot rodding.
and dont 100% disable all knock. Just burst knock vs airflow delta. which is a table that retards timing when there is a sharp change in calculated air flow.
yes you want the trims off while you tune the VE. I forgot to add to disable the DFCO
are you familiar with the commanded versus observed afr histogram?
I misspeak in a couple places ( you want to multiply by, not add to) but here's a vid I made awhile back.
no sweat on being new to tuning. no one is born knowing any of this. I was in your same shoes once, and I dont consider myself a computer person. But since i have started I've found that tuning is one of the more enjoyable parts of hot rodding.
and dont 100% disable all knock. Just burst knock vs airflow delta. which is a table that retards timing when there is a sharp change in calculated air flow.
I got the map sensor in and converted the pcm to 2 bar SD. I’m certain my tables are all off but I must say, it drives so much better at part throttle. I need to read up more on how to properly log data and make graphs and then what I do with all that data, but so far I’m so glad I finally converted and tuning it myself.
truckdoug thanks for all the tips.
truckdoug thanks for all the tips.
also some more notes since I have been doing some canned tunes for my youtube bros.
I put the maf high fail hz at the lowest cell on the table, usually 1500hz. then in the 1500hz and the adjacent cell i put 50lb/hr so the car will fire, idle and then fail the maf ----thanks to darth for that one.
turn off all fuel trims and disable burst knock.
i think thats all i got right off the top of my head
I put the maf high fail hz at the lowest cell on the table, usually 1500hz. then in the 1500hz and the adjacent cell i put 50lb/hr so the car will fire, idle and then fail the maf ----thanks to darth for that one.
turn off all fuel trims and disable burst knock.
i think thats all i got right off the top of my head
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TECH Apprentice
Joined: Jul 2006
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From: Columbus,Ga
sounds like you may have anther problem and disabling the maf is only masking the problem. you said the car runs lean with the maf unplugged. it should be richer, you may have a vacuum leak somewhere and the maf is saving your engine from running lean or there is problem with the tune
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Verdad Gallardo Smoke test showed no significant leaks anywhere and my wideband AFR is about 11.5 at wot. This is with the 2 bar SD tune. Before with the MAF tune my AFR was the same at wot, but went way lean at wot if I unplugged it so I never got on it. I’m thinking that would be accurate since the map 1 bar only went up to 105kpa and when you unplug the MAF it defaults to SD which wasn’t tuned above 105kpa. Or no? Anyways, I think my Ve table is pretty good now, just trying to dial in my low octane table.
If my spark advance is set at 22* at 6k rpm, and it has a KR of 4*, and the logfile shows it was actually at 18*, do I now change my octane table to 18*? Or 14*? This is on 9lbs of boost. When I originally converted to SD I just reused the low octane table that was from the MAF tune, which I am now trying to dial in. I’m not sure why it’s so far off since it was tuned “professionally” back when I had the MAF sensor.
If my spark advance is set at 22* at 6k rpm, and it has a KR of 4*, and the logfile shows it was actually at 18*, do I now change my octane table to 18*? Or 14*? This is on 9lbs of boost. When I originally converted to SD I just reused the low octane table that was from the MAF tune, which I am now trying to dial in. I’m not sure why it’s so far off since it was tuned “professionally” back when I had the MAF sensor.
Drop every cell in the wot area to the low teens? Then increase 1 or 2* until you get KR? I tried to open some files from the HPtuners repository but I keep getting error messages and can’t get them to open. I was going to see what other boosted applications were using.
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are you on pumpgas no meth? 2 bar? on a p01 computer? lemme look through my tune cab I might have something that fits your displacement and weight.
it's important to not that even with a 2 bar OS change, the spark table is in g/cyl vs rpm so it actually doesnt really follow MAP all the way into boost. what it does is go the the bottom row at the rpm you are at and use that cell to determine timing (before and adders or retarders for ECT, IAT and stuff like that)
it actually uses the bottom TWO rows to make that calculation. It might seems kinda hacky, but it works really well and simplifies things a great deal.
you're probably getting that error message because you havent upgraded to the newest 4.0 suite. before you do, copy all your tunes and your v3.36 or whatever version you have to a USB. once you download 4.0 it converts everything to be opened by 4.0 only. as you get further into tuning you'll find usefulness in havng tunes that can be opened with the earlier versions.
it's important to not that even with a 2 bar OS change, the spark table is in g/cyl vs rpm so it actually doesnt really follow MAP all the way into boost. what it does is go the the bottom row at the rpm you are at and use that cell to determine timing (before and adders or retarders for ECT, IAT and stuff like that)
it actually uses the bottom TWO rows to make that calculation. It might seems kinda hacky, but it works really well and simplifies things a great deal.
you're probably getting that error message because you havent upgraded to the newest 4.0 suite. before you do, copy all your tunes and your v3.36 or whatever version you have to a USB. once you download 4.0 it converts everything to be opened by 4.0 only. as you get further into tuning you'll find usefulness in havng tunes that can be opened with the earlier versions.
So here is a rather well sorted out 3 bar camaro tune. You can see how the spark table dips into the low teens in the peak torque area.
I would not copy the VE tables or the PE/BE tables. They are set to run very on edge fuel wise since this set up was refine over many years the fuel system was rock solid. I'd start out with at least 1.28 above 160kPa or 4000 rpm
another tip is instead of using KR as tuning tool, use it only as a "holy **** let off the gas" indicator. on pump gas, you'll stop making power even 3 or 4 degrees before KR is seen (depending on your sensor sensitivity levels)
the best way is the old way. pop a fresh couple plugs in around different cylinders like 1 7 4 8 are my faves (easiest to reach) make one WOT hit and then pull the plugs and see where the timing band is...ideally just below the bend in the strap, up to the bend itself.
I would not copy the VE tables or the PE/BE tables. They are set to run very on edge fuel wise since this set up was refine over many years the fuel system was rock solid. I'd start out with at least 1.28 above 160kPa or 4000 rpm
another tip is instead of using KR as tuning tool, use it only as a "holy **** let off the gas" indicator. on pump gas, you'll stop making power even 3 or 4 degrees before KR is seen (depending on your sensor sensitivity levels)
the best way is the old way. pop a fresh couple plugs in around different cylinders like 1 7 4 8 are my faves (easiest to reach) make one WOT hit and then pull the plugs and see where the timing band is...ideally just below the bend in the strap, up to the bend itself.
