Changing from a 2bar map to a 3bar map?
12-25-2006, 10:23 AM
#21
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Originally Posted by gametech
I tried before, but apparently logic and facts escape most of the people who responded to you original post.
Merry Christmas.
12-25-2006, 01:50 PM
#22
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Some Delphi Map sensor tech:
Stock 1 bar
kPa +-%Error
15 2.4
40 1.5
94 1.5
102 1.7
Delphi 2bar
kPa +-%Error
20 4.2
40 2.4
160 2.4
200 3.2
Delphi 3bar
kPa +-%Error
40 8.0
71 4.7
240 4.7
301 8.0
So when you change from a 1 bar to a 2bar you lose some accuracy.....same when you change from a 2bar to a 3bar....but the numbers are small enough to tune around and give you needed higher boost feedback.
Stock 1 bar
kPa +-%Error
15 2.4
40 1.5
94 1.5
102 1.7
Delphi 2bar
kPa +-%Error
20 4.2
40 2.4
160 2.4
200 3.2
Delphi 3bar
kPa +-%Error
40 8.0
71 4.7
240 4.7
301 8.0
So when you change from a 1 bar to a 2bar you lose some accuracy.....same when you change from a 2bar to a 3bar....but the numbers are small enough to tune around and give you needed higher boost feedback.
12-25-2006, 05:17 PM
#24
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Originally Posted by wait4me
SOME accuracy loss? LOL
Go Pull 8% from your tune or add 8% all at different times from 71 kpa down and no 2 times are the same and see how accurate your airfuel ratio is.. 8% is 16% total error. That is too much slop. AGAIN Post 5...
Go Pull 8% from your tune or add 8% all at different times from 71 kpa down and no 2 times are the same and see how accurate your airfuel ratio is.. 8% is 16% total error. That is too much slop. AGAIN Post 5...
I'm game for knowledge.
How is it possible that the 3bar tunes are working? My cruise commanded AF is +-0.1 right now.It's not +-0.0...but who cares? The car even starts
How do you control the "slop" at 20psi with a 2bar map? I went to SD to get away from RPM vs PE....even though that worked ok at 700rwhp with some major "slop".
Convince me with math that a 2bar is superior for a car running 20psi and I'll convert back.
12-25-2006, 05:22 PM
#25
Originally Posted by onfire
How do you control the "slop" at 20psi with a 2bar map? I went to SD to get away from RPM vs PE....even though that worked ok at 700rwhp with some major "slop".
Convince me with math that a 2bar is superior for a car running 20psi and I'll convert back.
Convince me with math that a 2bar is superior for a car running 20psi and I'll convert back.
12-25-2006, 05:23 PM
#26
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Originally Posted by wait4me
no it wont be valid anymore. only the 1 to 15 lbs of boost. All the rest will be shot.
A 3 bar cant see anything below 100kpa. So regular driving when not in boost will not be adustable unless you use a MAF
A 3 bar cant see anything below 100kpa. So regular driving when not in boost will not be adustable unless you use a MAF
This is not correct. 3bar map sensors do read below 100kPa.
12-25-2006, 08:14 PM
#27
ONfire, That post in number 22 gives very good info. HOWEVER It doesnt show i high enough break down of where each of the 2 and 3 bar are ACCURATE. The 2 bar has only a 1.6% from 60kpa to 140kpa, so to finish out the resolution on your list,
40 2.4
45 2.2
50 1.99
55 1.7
60 1.64
65 1.602
70 1.604
~~~~
160 2.4
Then same goes for the 3 bar. It shows that it went to **** for ACCURACY IN The NORMAL driving NON boosted cells.
BUT that sensor is within 1.4% of slop from 0 to 25sh lbs of boost. Then progressivly gets worse as it goes higher.
The reason why a 2 bar is better is because the more resolution you have in the areas that the vehicle will be in the better it will always run due to a better more accurate tune. We dont Drive in boost going down the highway or cruising down the road at 20-30 mph.
On the reasoning of me saying the 2 bar also is... Usually if you are making over 15lbs of boost you are usually floored and so the last column you can set that for the amount of fuel you need for the boost over 15. At wot you will-should hopefully be making the same amount of boost you have your WOT set to.. so usually the last column of ve that that sensor goes to is what i do the auto ve tuning to and it sets it perfect for any lb that you set it to.
Ive had
BIG BOOSTED cars my whole life "over 40". including 4 sitting in my garage right now. from 13lbs to 28.
40 2.4
45 2.2
50 1.99
55 1.7
60 1.64
65 1.602
70 1.604
~~~~
160 2.4
Then same goes for the 3 bar. It shows that it went to **** for ACCURACY IN The NORMAL driving NON boosted cells.
BUT that sensor is within 1.4% of slop from 0 to 25sh lbs of boost. Then progressivly gets worse as it goes higher.
The reason why a 2 bar is better is because the more resolution you have in the areas that the vehicle will be in the better it will always run due to a better more accurate tune. We dont Drive in boost going down the highway or cruising down the road at 20-30 mph.
On the reasoning of me saying the 2 bar also is... Usually if you are making over 15lbs of boost you are usually floored and so the last column you can set that for the amount of fuel you need for the boost over 15. At wot you will-should hopefully be making the same amount of boost you have your WOT set to.. so usually the last column of ve that that sensor goes to is what i do the auto ve tuning to and it sets it perfect for any lb that you set it to.
Ive had
BIG BOOSTED cars my whole life "over 40". including 4 sitting in my garage right now. from 13lbs to 28.
12-25-2006, 08:48 PM
#28
It sounds to me like people are confusing consistancy with accuracy. All the 3+ bar setups I have tuned or seen are very consistant. The loss of accuracy is easily compensated for and it doesn't mean that one second it's at a 14.7 a/f and the next at 15.8, just that it may be reading 40 kpa but it's really 43 kpa instead. The end result doesn't change all the time and is in fact very stable. And yes that standard GM part # for the 3 bar sensor reads down to 40 kpa and not just to 100 kpa. I would have to question the people who say otherwise as to how many 3 bar or higher setups they have actually worked with.
12-25-2006, 10:26 PM
#29
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Originally Posted by wait4me
ONfire, That post in number 22 gives very good info. HOWEVER It doesnt show i high enough break down of where each of the 2 and 3 bar are ACCURATE. The 2 bar has only a 1.6% from 60kpa to 140kpa, so to finish out the resolution on your list,
40 2.4
45 2.2
50 1.99
55 1.7
60 1.64
65 1.602
70 1.604
~~~~
160 2.4
Then same goes for the 3 bar. It shows that it went to **** for ACCURACY IN The NORMAL driving NON boosted cells.
BUT that sensor is within 1.4% of slop from 0 to 25sh lbs of boost. Then progressivly gets worse as it goes higher.
The reason why a 2 bar is better is because the more resolution you have in the areas that the vehicle will be in the better it will always run due to a better more accurate tune. We dont Drive in boost going down the highway or cruising down the road at 20-30 mph.
On the reasoning of me saying the 2 bar also is... Usually if you are making over 15lbs of boost you are usually floored and so the last column you can set that for the amount of fuel you need for the boost over 15. At wot you will-should hopefully be making the same amount of boost you have your WOT set to.. so usually the last column of ve that that sensor goes to is what i do the auto ve tuning to and it sets it perfect for any lb that you set it to.
Ive had
BIG BOOSTED cars my whole life "over 40". including 4 sitting in my garage right now. from 13lbs to 28.
40 2.4
45 2.2
50 1.99
55 1.7
60 1.64
65 1.602
70 1.604
~~~~
160 2.4
Then same goes for the 3 bar. It shows that it went to **** for ACCURACY IN The NORMAL driving NON boosted cells.
BUT that sensor is within 1.4% of slop from 0 to 25sh lbs of boost. Then progressivly gets worse as it goes higher.
The reason why a 2 bar is better is because the more resolution you have in the areas that the vehicle will be in the better it will always run due to a better more accurate tune. We dont Drive in boost going down the highway or cruising down the road at 20-30 mph.
On the reasoning of me saying the 2 bar also is... Usually if you are making over 15lbs of boost you are usually floored and so the last column you can set that for the amount of fuel you need for the boost over 15. At wot you will-should hopefully be making the same amount of boost you have your WOT set to.. so usually the last column of ve that that sensor goes to is what i do the auto ve tuning to and it sets it perfect for any lb that you set it to.
Ive had
BIG BOOSTED cars my whole life "over 40". including 4 sitting in my garage right now. from 13lbs to 28.
Godspeed on running 28psi on a 2bar map SD tune....I'm glad it's working for you.
Many others as posted above and on the FI forum (and myself) are using a 3 bar map without "crap slop results" at part throttle. My commanded AF vs actual is within +-0.10 cruising around town....good enough for me. So we'll agree to disagree about the accuracy of a 3bar map.
12-26-2006, 02:44 AM
#30
I just ordered the GM #12223861 3 Bar MAP sensor for my Turbo car. I will be using it with my EFI Live / RoadRunner setup. I figure I wont be running more than boosting more than 22lbs anyway so it shouls\d work out for me.
Then again the next combo will see a BS3 setup. Once the 91.5mm turbo goes on there no point in using the stock PCM anymore...
Then again the next combo will see a BS3 setup. Once the 91.5mm turbo goes on there no point in using the stock PCM anymore...
12-29-2006, 08:31 PM
#31
EC_Tune a mod on hptuners forum posted this site http://www.powerandsignal.com/Products/Pressure.aspx which gives a rundown of the accuracy or lack thereof for most delco MAP sensors.
12-29-2006, 09:31 PM
#32
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Here is a 3bar screen shot that shows a cruise with a 44kPa reading and a changing TP. Note the command AF and the actual AF from the wideband. It will give you an idea of the accuracy you can get from a 3bar.
12-30-2006, 04:22 AM
#35
TECH Fanatic
Originally Posted by foff667
EC_Tune a mod on hptuners forum posted this site http://www.powerandsignal.com/Products/Pressure.aspx which gives a rundown of the accuracy or lack thereof for most delco MAP sensors.
Its only really accurate in a narrow range of temps and kpa.
Going by this 3bar sensor doc http://www.powerandsignal.com/docs/P...re_sensors.pdf
12-30-2006, 09:16 AM
#36
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Originally Posted by gametech
I hate to be the one to get banned for bashing sponsors... But damn, a "pro tuner" who doesn't know what a map sensor does and can't read a datalog, this is just getting ridiculous.
I'm a moderator and I'll ban you for making me laugh so hard
12-30-2006, 10:05 AM
#37
Originally Posted by gametech
I hate to be the one to get banned for bashing sponsors... But damn, a "pro tuner" who doesn't know what a map sensor does and can't read a datalog, this is just getting ridiculous.
You have issues. Now your saying i cant read a log? What a moron. That picture CLEARLY shows what every value and Values it has going on.
I guess i will have to Explain that data log to you since you dont know what you are looking at................
Bottom right hand corner has ftc# 22. OK, that means that the Pcm is in power enrichment mode/open loop. Now follow the blue line in the window right next to it and it has a flat line all the way accross the board meaning that it was there and hasnt moved..
Now, Look up 5 perameters from that FTC#. "In case you cant count, just go up the number of fingers you have on one hand" OK, now you see o2 sensor voltage bank 1 sensor 1. That is the front o2 sensor on the drivers side, It is showing .825. What is .825 in air fuel ratio? Exactly....... A 14.6 would be .480-.500 ish depending on o2 sensor brand. NOW look at the YELLOW line next to that perameter, HMM it dont go under 790 the whole time, SO that means that it is not at 14.7 or even close.
Now for the commanded Airfuel ratio that is in the log, Get ready, cause this is tricky, you have to move your Eyes allllll the way to the other side of the picture. Up at the top, the second one down, is what the pcm is commanding at that exact time. And by looking at the graph line in purple it shows that has been the commanded airfuel the whole time.
Want me to explain the rest?
12-30-2006, 12:00 PM
#38
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Originally Posted by wait4me
Your car is in power enrichement cell 22 and the o2 mv are at 13.6 air fuel and steady? But your car is commanding 14.37?
START YOUR OWN THREAD ABOUT YOUR 28PSI TUNES USING A 2 BAR MAP SENSOR AND WHY IT'S SUPERIOR TO A 3 BAR TUNE.
I can't believe you looked at a screen shot that shows a 3 bar map sensor running under 100kPa with a commanded AF very close to the Actual AF from a WIDEBAND 02 sensor and you quote the narrowband 02 sensor output.
WHY?
Surely you realize a WIDEBAND O2 sensor is more accurate than a stock narrow band????
My tune was made in forced open loop SD COS5. There is a table in EFI Live that allows you to set the AF wherever you want it. I WANT IT AT 14.37 at cruise for reasons I would never attempt for you to understand.
The WIDEBAND reported actual AF line at changing TP% is very close to the Commanded AF as noted in the top right corner of the screen shot....see how one line overlays the other from left to right across the screen with different throttle positions and different (less than 100kPa) map sensor data.....that's a good thing.
