Running Lean on Top end... MAF calibration?
Running Lean on Top end... MAF calibration? Hey all!
I am trying to richen up the top end of the car but im not sure how to do it. Currently I am using the MAF-AFR error histogram in hptuners. And then going into the editor and copy and pasting the error % into the MAF calibration curve. Which increases the top part of the curve some more.
Now is this the correct way to richen up the top end? I am currently running about 12.2 afr and im trying to reach commanded of 11.7.
Thanks All
I am trying to richen up the top end of the car but im not sure how to do it. Currently I am using the MAF-AFR error histogram in hptuners. And then going into the editor and copy and pasting the error % into the MAF calibration curve. Which increases the top part of the curve some more.
Now is this the correct way to richen up the top end? I am currently running about 12.2 afr and im trying to reach commanded of 11.7.
Thanks All
Nope.. no boost.. I wish! but no..
I was just assuming that 11.7 was the optimal air fuel ratio for power. I mean thats basically what the pcm is trying to get to correct?
i dont know.. maybe i just have a complex at trying to see my afr error % at 0.
I was just assuming that 11.7 was the optimal air fuel ratio for power. I mean thats basically what the pcm is trying to get to correct?
i dont know.. maybe i just have a complex at trying to see my afr error % at 0.
12.8-13.0 is where max WOT is found for most of us (naturally asperated). 12.8 to be safe. You're losing ponies @ 11.7. Have you noticed the smell of gas in your oil when you change it? If so, I'd change the oil again after running so rich if many WOT pulls have been made.
12.8-13.0 is where max WOT is found for most of us (naturally asperated). 12.8 to be safe. You're losing ponies @ 11.7. Have you noticed the smell of gas in your oil when you change it? If so, I'd change the oil again after running so rich if many WOT pulls have been made.
Good to know..
I guess i wont try and increase the MAF curve anymore.
So is dialing back the MAF curve the best way to get back to 12.8? Right now I peak at about 12.2 and it dials back to around 12.6 towards the top of the band.
Thanks
It's up to you whether or not to manipulate the MAF table or to modify the VE table. Personally, I would set the MAF up so that the STFT's are close to 0 @ idle & then change the MAF settings accordingly. What I did was use a stock MAF table in order to establish a baseline & then increased the settings from 400-2000 RPM 5-10% at a time until the STFT's were -3 to zero. Afterwards multiplied the remaining MAF table settings by the final % used to get -3 to 0 STFT's during idle. So, when finished, all of my MAF settings increased by 26.5%. This is how you calibrate the MAF to indicate the correct air flow. I have seen guys have to increas the top end of the table a bit more, but, this is basically the way to set it up. After you do this, the VE tables will need to be modified so that you get 14.6-15.5 to 1 under normal driving conditions & 12.8 to 1 from 70-75 KPa MAP pressure & above.
Or you can just keep what you have & tweek the MAF table for 12.8 to one above 70-75 KPa MAP & 14.6 ish under normal driving conditions.
EDIT: this was written before seeing the 12:40 Frost post. I think Frost is eluding to the fact that your MAF & & VE tables are not properly set up.
Or you can just keep what you have & tweek the MAF table for 12.8 to one above 70-75 KPa MAP & 14.6 ish under normal driving conditions.
EDIT: this was written before seeing the 12:40 Frost post. I think Frost is eluding to the fact that your MAF & & VE tables are not properly set up.
Trending Topics
VE has little-to-no bearing on WOT if the MAF is in the mix. The VE is 100% out of the window by 4K. PE is WOT commanded AFR (in EQ), so if you are commanding one thing and getting another, it's in the MAF curve (assuming proper IFR).
The people that jack the PE around to get WOT in range are really just determining MAF error in a round-a-bout way. When they cheat, say, 7% at 5K RPMs, if you were to look at logged freq, this "cheat" factor reflects the error in that cell.
The people that jack the PE around to get WOT in range are really just determining MAF error in a round-a-bout way. When they cheat, say, 7% at 5K RPMs, if you were to look at logged freq, this "cheat" factor reflects the error in that cell.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo When I am working the MAF, I put the car in OL, goto dynamic airflow and set the high RPM disable to 1200-1500 to put the car "on the MAF", take 3-4 out of the HO table at .48 and higher, and set it to command 12.9 in OL and in PE so that there is no transition in commanded fueling. You can get that hump in the middle of the curve that'll take a while to go over otherwise.
Last edited by Frost; Aug 19, 2008 at 09:12 PM.
