Finally tuned maf steps outlined
06-13-2005, 09:42 PM
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Finally tuned maf steps outlined This is on a 5.3 with head work and cam along with supporting boltons.
Thanks to TXhorns and soundengineer for help I wish I could take credit for this but they taught me I just tweeked it some.
I started by tuning the ve in SD and got all lt and st trims below 3% error. Next I went on to try and tune the maf. I used redsupras sheet and also tried audio's lt trim sheet they both made the same curve but all lt trims in the lower regions where way negative. So after some searching and help from TX I went back through looked at the numbers and went with the stock 5.3 curve. The trims where now all positive. So I knew it was some where in between. Decided to use the 99-00 stock f body curve and began tweeking. I made a simple excel sheet just as reference for corrected values (see below).
What I did was to log maf hz in the pid and drove around till all the neg trims where learned. Then I went through and scanned the chart with the cursor I noted the trim cells and values then looked over at the maf Hz. The key I found is getting the range of Hz correct for example your running the cursor over the chart display and from 3400-5000HZ you see the trim cells its hitting and they are all -10 so you know to multiply that range by 0.9246. When logging try not to go into pe mode and no spinning the tires it creates incorrect readings. Also change the decimals to 5 instead of 2 in the maf table. It took me 3 runs and now my lt's are within 2% and st are 5%.
Ive noticed I get better mileage, I can run more timing, more power and throttle response is vastly improved even over SD Im amazed at the difference 1/1000 will make in the maf table. Also I have a large cam and before I would get bucking and shacking under load below 2k rpms now its very smooth and drivable even for this cam in a small motor some of the lope is gone but thats a small price to pay. Its very drivable now. Hope this helps out anyone needing to dial in the maf its well worth the effort.
Thanks to TXhorns and soundengineer for help I wish I could take credit for this but they taught me I just tweeked it some.
I started by tuning the ve in SD and got all lt and st trims below 3% error. Next I went on to try and tune the maf. I used redsupras sheet and also tried audio's lt trim sheet they both made the same curve but all lt trims in the lower regions where way negative. So after some searching and help from TX I went back through looked at the numbers and went with the stock 5.3 curve. The trims where now all positive. So I knew it was some where in between. Decided to use the 99-00 stock f body curve and began tweeking. I made a simple excel sheet just as reference for corrected values (see below).
What I did was to log maf hz in the pid and drove around till all the neg trims where learned. Then I went through and scanned the chart with the cursor I noted the trim cells and values then looked over at the maf Hz. The key I found is getting the range of Hz correct for example your running the cursor over the chart display and from 3400-5000HZ you see the trim cells its hitting and they are all -10 so you know to multiply that range by 0.9246. When logging try not to go into pe mode and no spinning the tires it creates incorrect readings. Also change the decimals to 5 instead of 2 in the maf table. It took me 3 runs and now my lt's are within 2% and st are 5%.
Ive noticed I get better mileage, I can run more timing, more power and throttle response is vastly improved even over SD Im amazed at the difference 1/1000 will make in the maf table. Also I have a large cam and before I would get bucking and shacking under load below 2k rpms now its very smooth and drivable even for this cam in a small motor some of the lope is gone but thats a small price to pay. Its very drivable now. Hope this helps out anyone needing to dial in the maf its well worth the effort.
Last edited by 02sierraz71_5.3; 06-17-2005 at 07:06 PM.
