Speed Density or Maf Tune ?
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From: wellington fl/ stx vi
Speed Density or Maf Tune ? So i got my Eps cam 234/246 111 duration installed in my 02 z28 and have a question, which tune is better for my cam with a all stock block heads and intake.
Any input will be apreciated
Any input will be apreciated
youre gonna get all kinds of opinions. i would keep the maf if its a daily driver and not maxing out the maf. with only the block stock, my car is still not maxing out the maf. its heads, cam, intake but no forced induction.
with a blower or turbo and modified, you could be nearing the maf max.
with a blower or turbo and modified, you could be nearing the maf max.
Both work just fine. On a daily driver I would keep the MAF. I built a good SD tune, then enabled the MAF and dialed in the MAF table to maintain the SD AFR. My reason for this is if the MAF was to fail there is no worry of the AFR going way out of whack.
I've got a similar setup (347, AI 243's, 236/242 cam) and I love SD. I do my own tuning though, and even though the MAF is great and dead accurate for fueling, the throttle response with the SD tune is noticeably better. I've ran both, tuned both, and like the MAF, but in my personal application I'm all SD...
That being said, I don't know that with an 85mm MAF there'd be a real performance difference at the track. If anything, you'd have more accurate fueling without dealing with the inherent IAT sensor heat soak issues.
That being said, I don't know that with an 85mm MAF there'd be a real performance difference at the track. If anything, you'd have more accurate fueling without dealing with the inherent IAT sensor heat soak issues.
SD tune all the way every day. I run an open-loop SD tune using the HP Tuners 1 Bar MAP OS. I admit, I tune it often, but it never changes a LOT day to day. In fact, I updated it today after a major change in the weather and the worst I saw was -4% with most being under 1%. Throttle response is nice and snappy and I can force a lean cruise using the open-loop VE multiplier. Oh, and I went from MAP readings at WOT between 92 and 94 kpa, with the 85mm maf and 3.5" intake tube to 95 to 100 KPA with no MAF and a 4" intake tube.
SD tune all the way every day. I run an open-loop SD tune using the HP Tuners 1 Bar MAP OS. I admit, I tune it often, but it never changes a LOT day to day. In fact, I updated it today after a major change in the weather and the worst I saw was -4% with most being under 1%. Throttle response is nice and snappy and I can force a lean cruise using the open-loop VE multiplier. Oh, and I went from MAP readings at WOT between 92 and 94 kpa, with the 85mm maf and 3.5" intake tube to 95 to 100 KPA with no MAF and a 4" intake tube.
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i run a sd tune on my formula and its great , but my tuner know what hes doing , the one thing that does blow is that since their isnt a maf that if the map sensor dies , your car will just idle and can leave you stranded.
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From a tuning standpoint, MAF is actually much easier as you're tuning to frequency. If you have Banish's book, you'll see the formula for converting MAF frequency to VE table counts and you can make your own custom PID to extrapolate the data for you to fill out the VE table automagically.
The alternative is driving around and logging with the wideband all of the data for the cells in the VE table with A/F % avg difference calculated. Then you just copy it over and you're done. It might be slightly more accurate, but it does take longer to do. On my personal car, that's what I did. And I can always do that anytime there is a weather swing to tighten up the A/F.
I do have the MAF on the car still, but I'm running 1-Bar SD PCM now and run it OLSD.
The alternative is driving around and logging with the wideband all of the data for the cells in the VE table with A/F % avg difference calculated. Then you just copy it over and you're done. It might be slightly more accurate, but it does take longer to do. On my personal car, that's what I did. And I can always do that anytime there is a weather swing to tighten up the A/F.
I do have the MAF on the car still, but I'm running 1-Bar SD PCM now and run it OLSD.
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From: wellington fl/ stx vi
Thanks guys
So what do i need to do to SD tune other than disconnect the MAF sensor ? Sorry guys put am on an Island with very little resources all the help and suggestions i get are truly appreciated
So what do i need to do to SD tune other than disconnect the MAF sensor ? Sorry guys put am on an Island with very little resources all the help and suggestions i get are truly appreciated
No, there's quite a few things to change in the tune. You can leave your MAF connected or remove it, but you want the PCM to see it has failed and revert back to SD. Sometimes, it might take a moment to start as the PCM does this.
This is a good guide for going into SD mode:
http://www.hptuners.com/help/vcm_edi...to_user_sd.htm
This is a good guide for going into SD mode:
http://www.hptuners.com/help/vcm_edi...to_user_sd.htm
You'll need a wideband o2 to find the %AFR error to apply to the VE table.
P0101, 102 amd 103 are not set to MIL on 1st error. Also don't know which tune you are using since there are 2 posted. The second one has really high values in the idle RAF table.
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From: wellington fl/ stx vi
ok thanks.
one last question, i tried to open the ve-idle-config file and it didnt open. do i need to open it when running hptuner editor or scanner ?
thanks again for all the info
one last question, i tried to open the ve-idle-config file and it didnt open. do i need to open it when running hptuner editor or scanner ?
thanks again for all the info