93' Miata stolen and flipped build thread
#2752
On a more serious note. What is the easiest/quickest way to change a fuel map for a much higher altitude?
The drive between St George and Cedar City is a 3,200ft of elevation gained. The car starts running really lean at 6k feet and my whole VEAL map gets pretty messed up. Starting the car up I'm all of a sudden idling at 16.7 instead of being stoic.
Not sure how to load a new map or if I need to apply a different tune with settings applicable to 6k elevation.
The drive between St George and Cedar City is a 3,200ft of elevation gained. The car starts running really lean at 6k feet and my whole VEAL map gets pretty messed up. Starting the car up I'm all of a sudden idling at 16.7 instead of being stoic.
Not sure how to load a new map or if I need to apply a different tune with settings applicable to 6k elevation.
#2754
On a more serious note. What is the easiest/quickest way to change a fuel map for a much higher altitude?
The drive between St George and Cedar City is a 3,200ft of elevation gained. The car starts running really lean at 6k feet and my whole VEAL map gets pretty messed up. Starting the car up I'm all of a sudden idling at 16.7 instead of being stoic.
Not sure how to load a new map or if I need to apply a different tune with settings applicable to 6k elevation.
The drive between St George and Cedar City is a 3,200ft of elevation gained. The car starts running really lean at 6k feet and my whole VEAL map gets pretty messed up. Starting the car up I'm all of a sudden idling at 16.7 instead of being stoic.
Not sure how to load a new map or if I need to apply a different tune with settings applicable to 6k elevation.
I found this LINK but I am trying to gather up more details about the whole process. It is a start... but I wish I could deliver a more complete answer for you (still researching).
#2757
I am dealing with that same issue when traveling from Cedar to St George and back as well. I have one of Revs MS2's and I installed the mapdaddy with two sensors, so I would have a second sensor for outside air pressure
Ive checked all my soldering joints and I made sure everything is in the correct place, but no matter what I do, when I change settings to use it, it just reads outside air pressure at 100 constantly and makes car run like crap.
Air pressure in cedar is around 82-83, and was around 96 last time i was in St George.
Heading down is not much of an issue, but when I travel back uphill though, I gain some speed and have it do a reboot on the road, maybe twice on the way up.
(neutral, turn car off, wait a bit to make sure engine has stopped, turn car on to get new "initial" reading, turn back on, match revs) It is annoying as hell, I want to get the other sensor working.
It samples the air pressure when you start for a base reading, at Cedar city at about 5600 ft air pressure is 83 kPa, if you go to the ocean, where it is 101 kPa, it compensates by adding more fuel based on the initial reading. When you drive and your altitude changes by about 4000 ft within an hour it makes the car run like crap because it is either putting too much fuel or not enough because it thinks the outside air pressure is the same as where you cranked the car
Ive checked all my soldering joints and I made sure everything is in the correct place, but no matter what I do, when I change settings to use it, it just reads outside air pressure at 100 constantly and makes car run like crap.
Air pressure in cedar is around 82-83, and was around 96 last time i was in St George.
Heading down is not much of an issue, but when I travel back uphill though, I gain some speed and have it do a reboot on the road, maybe twice on the way up.
(neutral, turn car off, wait a bit to make sure engine has stopped, turn car on to get new "initial" reading, turn back on, match revs) It is annoying as hell, I want to get the other sensor working.
I still don't understand why you'd need baro correction if you're using a MAP at the manifold anyways.
#2759
Well, sure. Kinda?
I had the MSM up to 12k feet last year. Yes, it ran a little weird, but we're talking elevation where the car was only pulling 15-16" of vacuum on full decel.
What i'm not braining is why it matters. You're measuring what's going on in the manifold, not what's going on outside of the car. Air density may change outside of the car, but does that really matter? Wouldn't less air just mean less pressure means less map reading?
Boost means more air in a given space = more dense, yes?
If there's somehow less air being put into the motor at a given kPa, wouldn't the car actually run RICH, not lean?
I'm probably missing something big. Or i am teh smrts?
I had the MSM up to 12k feet last year. Yes, it ran a little weird, but we're talking elevation where the car was only pulling 15-16" of vacuum on full decel.
What i'm not braining is why it matters. You're measuring what's going on in the manifold, not what's going on outside of the car. Air density may change outside of the car, but does that really matter? Wouldn't less air just mean less pressure means less map reading?
Boost means more air in a given space = more dense, yes?
If there's somehow less air being put into the motor at a given kPa, wouldn't the car actually run RICH, not lean?
I'm probably missing something big. Or i am teh smrts?
#2760
As I read on another forum while reasearching this a litttle,
I too am confused on why the car runs lean at a higher altitude. In my brain it only makes sense that it would run more rich, rather than an almost full 2 point afr change towards lean.
Weird thing is that even after cycling my key on and off it wouldn't change the initial Baro reading.
Need to do some more reading on this.
A turbo brings you xx PSI above the pressure of the environment. If the pressure of the environment is lower to start with, the absolute pressure after the turbo will be too.
Weird thing is that even after cycling my key on and off it wouldn't change the initial Baro reading.
Need to do some more reading on this.