As we all know the HPX MAF sucks bawls <= 1.2 volts or so... How successful has it been getting the idle perfect like stock? I've always had some slight A/F and RPM fluctuations at idle (+/- 50rpm and +/- 0.5 A/F) and pretty much the only way to get it 100% spot on and steady is to completely flatten the MAF table under 1.17 volts. But then you get occasional rich/lean conditions depending on whether the A/C is on or off...fixing one thing always breaks another thing.

 

I'm not a tuner myself, but I do use the HPX MAF w/ my tuner and yes the resolution sucks on the lower end...and my idle goes somewhat funky when I turn on the AC, no matter what my tuner tries...still driveable, just not ideal...I also see similar idle issues when my AIT's increase significantly...

Uprev recently came out with their own versions of upgraded MAF's with promises of better resolution:

http://secure.uprev.com/accessories?p=2

I'm tempted to try these out, but they are more expensive than the HPX, and I'll have 2 HPX paper weights laying around...

 

Have you guys tried tuning a different area in the Osiris?

 

Umm, like where? You have your MAF table and fuel corrections. There isn't enough resolution in the fuel corrections table to account for the different loads of A/C being on or off... only the MAF table has the resolution but unfortunately the MAF itself does not!

I also notice a variance when AIT increases... fuel schedule actually moving backwards when RPMs climb during full boost...cool, huh? If there's a better MAF, I'll be all over it.

 

The new and improved and so we hope!
http://secure.uprev.com/accessories/uprev-maf-gt.html

 

Ouch...$350? I guess I can live with HPX LOL.

 

What do you have your idle set at? Also is yours a 2004.5?

 

i dunno, if 350$ was the only thing keepign me back from a smooth idle, it would be worth it for sure. I would nail down with UPrev that if its not as advertised, money back, no restock fee.

 

I haven't had any issues with a PMAS.

 

My idle isn't bad enough to justify it. A slow +/- 50rpm cycle isn't THAT annoying. But it took alot of work to get it there and re-doing the whole tune from scratch (swapping the MAF with a different type requires a full and complete retune) isn't exciting to think about.

Starting from scratch it would definitely be worth the extra $$ though..and if it gives more accurate boost resolution that would be an even bigger +.

~Randy