VE is closer, how close and MAF questions...

The VE tuning is getting closer and closer to 13.0 AFR, I have made 5 tuning cycles today from logging nice long drives with the LC1 wideband HPT 2.0 EIO, and the wideband AFR %error histogram applications to primary and secondary VE.
A few questions :
1) How close do you generally get before you turn the MAF back on ? I have everything between 0 and -10% across the board in the AFR Error %. Doesn't the change in outdoor barometric pressure change it somewhat ?
2) Do I need to rescale my MAF (I'm guessing yes ) ? What histogram and table in HPT 2.0 does the maf recalibration ?
3) If I am hitting the 105kpa MAP ceiling under even moderate throttle, is it safe to say I need a 2-bar MAP ? I have the 2-bar HPT upgrade.
Thanks for your continued help.

Rob (Bad30th)

set it up just like you would drive it...
start with OLFA at 1.00
set PE to enguage where you would normally want it to turn on using teh PE enable TPS vs RPM table
and are you using teh LC1 as is or were you smart enough to set it to respond at the 1/12th second output rate. the problem with instant response(factory default) is that your scanner reads at a much slower rate...and the LC1 could be reporting a lean pocket inbetween pulses...if you scanner picks this up you get a false lean condition....
you have an equation in your pcm that takes into account for pressure changes so it doesnt really change all that much...I have seen less than 2% change from day to day on my car...what gets you more is engine coolant temperature....cold temperature need more fuel to burn properly


Rob (Bad30th)
glad to be of some help to you
Re the 13.0 - I'm following the instructions of a speed-density 'how-to' from HPTuners website by WS6snake-eater, it says :
3: Change all points to 1.13 in the Open Loop F/A vs ECT vs MAP table (commands AFR of 13.0) This will assure that you have a safe mixture to work with when reaching the higher end of the RPM band. Don't worry we will be chaning it back later, this is for logging purposes only.
Haven't touched the LC1 config, it's out of the box. I will see if I can get it set to the 1/12th rate. Thanks for the tip.
I'll keep working on VE until I can get the numbers a little closer then... Most are 0 to -5 but there are still some up to -10 around some cells.
I'll grab the histograms for MAF - AFR Error% from your website and get the 2-bar MAP on order.
Thanks again for your help.

Cheers,
Rob (Bad30th)
this will guarantee the most accurate results and it will be exactly as you drive it.
set pe map to 0(this means it is armed and ready to go all the time)
set pe delay to 0
set pe enable tps to the stock table or even lower some of the cells so that it commands the pe value earlier if you want.
set the pe value to the A/F you desire....
if you want 12.5 for your PE amount then you put the value at 1.704 (14.63/1.704=12.5)
the problem with the 13.0 OLFA is that it results in numbers that are wrong when you convert the table back to 14.63
I dont know why..I just know that it does from my first time tuning with a wideband..tested on my own car...
was dead on within .1 fo dead on...put it back to 1.0 and it was off by way more than that..some lean some rich..but either way it was off and I had to do it all over again

HPT help file has a good version of wideband tuning written by foff...this is teh standard method...otherwise it would not have made the help file
Tomorrow I will set the Open Loop F/A vs ECT vs MAP table back to what it was before and log some more, and will take another look at the HPT Help wideband how-to.
About the MAF, just log with that histogram (with the MAF plugged in obviously) and paste over my MAF table ? I'm amazed how much easier tuning has become over the last couple of years.
Thanks,
Rob (Bad30th)
you can just set the table to all 0's that biases it all towards IAT
the table is in the airflow tab along with your VE and MAF tables
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Made the changes above (now using HPT help widband SD tuning how-to) and made two logs/tunes this morning. The car fired right up and didn't have the usual stumble, which was an unexpected bonus !
I reset OLFA table to 1.0 across the board (it was all over the place) and set PE to this :
0-2400 RPM = 1.0 (stoich)
2800-3600 RPM = 1.1 (13.29 AFR)
4000-4400 RPM = 1.2 (12.1 AFR)
4800-5600 RPM = 1.25 (11.70 AFR)
6000-7200 RPM = 1.3 (11.25 AFR)
That look like safe AFR for an FI car (9psi) ? Looking at the logs AFR error % is getting more and more dialed in, still doing more VE tuning.
By the end of the second tuning pass I could see why some people don't turn the MAF back on at all, it's driving awesome already - almost all the wierd surging at cruise I had is gone.

Thanks,
Rob (Bad30th)
By the end of the second tuning pass I could see why some people don't turn the MAF back on at all, it's driving awesome already - almost all the wierd surging at cruise I had is gone.

That's what I have on the PE tab. Is it somewhere else ?
Rob (Bad30th)
set that delay rpm to 0
check your settings...make sure you are in "advanced" mode and not in basic or standard modes..in teh settings in the edit tab>view>basic/standard/advanced
if you can get it closer..the go as tight as you want...otherwise..yes close enough
do the maf the same way
That's what I have on the PE tab. Is it somewhere else ?
Rob (Bad30th)






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