1badls1bird

What about a Pace PArts LS6 maf? Will that jave a detrimental affect on the tranny? Thanks!

Patrick G

iTrader: (14)

Again, as posted numerous times above, you can safely run the popular 85mm MAFs like the Pace & SLP MAFs since they're claibrated. Your pcm won't be able to tell the difference between that and a stock unported MAF...and neither will your tranny. <img src="gr_stretch.gif" border="0">

Chris99WS6PWTMET

Patrick,

Thanks for all the info on my question. Thanks also to the others that chimed in with advice!! I will be putting the stock ends back on but first I gotta run it at the track Saturday with the ported ones. Test drove it today with no pinging. Its a shame that the MAF and PCM have that much control over so many aspects of engine/tranny operation. <img src="gr_sad.gif" border="0">

J'sRamAir

Hmmm...this is the first time I've heard of this. Is this just concerning A4s?

FormulaWS6

Patrick, how about stock MAF ends unported, BUT with the screen out?? Thanks..

[ February 01, 2002: Message edited by: FormulaWS6 ]</p>

Red2000SS

[quote]Originally posted by Nine Ball:
<strong>Ahhhh, chalk this one up as another advantage of owning a 6-speed car. <img src="gr_grin.gif" border="0">

Tony</strong><hr></blockquote>

LOL <img src="gr_grin.gif" border="0"> , yes you M6er's don't have to worry about this one. Instead you have other joys such as:

Can you help me find all the pieces of my driveshaft? <img src="graemlins/gr_cry.gif" border="0" alt="[whiner]" /> By the way what's that awful stink, my stock clutch seems to have taken a dump <img src="gr_sad.gif" border="0">

and "Do you think if I spend > $2000 for a 12-bolt I might be able to run down the track more than once?" LOL

There is always pros and cons...

Patrick G

iTrader: (14)

Colonel and all:

As you know, porting a mass air flow sensor increases the area of incoming air going across the hot wire sensors, thus tricking the MAF into reading less air. By reading less incoming air, the MAF sends a signal to the computer to lean out the mixture, increase timing and lessen transmission line pressure. The O2 sensors will communicate back with the pcm to richen the mixture based on long term data acquisition (hence the L-Trims increasing to a large positive number). The increased timing will remain high and will not back down and the line pressure will remain lower and will not go back up.

If you have a stock MAF and your car is running rich, you can lean it out with a MAF translator. If you only adjust the WOT setting, you will not affect timing or trans line pressure. So, if you turn the WOT pot a click or two lean, your A/F ratio should be where you want it to be without resorting to positive L-Trims, increased timing, and lower tranmission line pressure.

If you instead, adjust the MAFT base setting, this will change the whole landscape of how the MAF reads incoming air.

A calibrated GMS MAF or any of the popular calibrated 85mm MAFs should give the same timing, and trans line pressure readings as a stock unported MAF...so I guess I would say that you'd be fine with them.

2000 Camaro SS

Stupid question...I'm assuming this is auto trans? I gosta ask.

AFTICA

iTrader: (8)

[quote]Originally posted by Patrick G:
[QB]Colonel and all:

If you only adjust the WOT setting, you will not affect timing or trans line pressure. <hr></blockquote>

Based on the Atap runs I made last night,I have to respectfully disagree with this statement.Timing with the MAFT set to 0/0,was definately lower on average,than with it set to 0/-4.I don't have the line pressure problem so I can't agree or disagree on that yet.I will log Maf flow rate with the ends & with the MAFT set to say -4% WOT with out the ends as soon as I get a chance.I suspect that the readings will be very close.

Patrick G

iTrader: (14)

FormulaWS6: Yes a screenless stock MAF will work fine...that's how I run my car.

As far as WOT settings not affecting timing or line pressure, I haven't seen it. Of course, I've never needed to make more than 2 clicks rich or lean on the MAFT to get right where I need to be so I guess if you adjusted it more than that it might. Think about it this way, if you are running about 15-20% positive L-Trims, that means your MAF is reading about 15-20% less incoming air. That said, the pcm is probably calculating about 15-20% less load across the board. It's been my experience that trimming the WOT pot on the MAFT (to richen or lean out the WOT a/f ratio) has no affect on long term fuel trims (L-Trims). If there is no affect on L-Trims, then it seems unlikely for there to be much change in calculated load, timing, or transmission line pressure simply by turning the WOT pot alone. I could be wrong, but as I said before, I haven't seen it on 4 of my LS1 powered vehicles.

mmiller

iTrader: (1)

Patrick,

If I put the stock un-screened MAF ends back on, how much timing do you think I will lose (I can get 28 degrees now with the stock ported ends on my '01 Z28), and can I get it back by tuning with the MAFT? What are your thoughts as far as performance difference / gains between the 85MM MAF vs. the stock MAF? Is it worth the money?

[ February 01, 2002: Message edited by: mmiller ]</p>

Patrick G

iTrader: (14)

mmiller:

Unfortunately, you will lose around 3-4 degrees of timing by putting the stock MAF ends back in. You can't get the timing back with a MAF Translator without lowering calculated load and transmission line pressure either.

You have two solutions: Install a HPP3 and use the power tuning with a stock screenless MAF (or calibrated 85mm MAF from Pace or SLP) or have a shop you trust (MTI, Ed Wright, Steve Cole, etc) add timing through programming. The ultimate scenario is to get your own LS1 edit program. The HPP3 will give you an easy 28 degrees of timing with a stock MAF (or 85mm MAF). With the HPP3 and a stock MAF, you can have 0% L-Trims, 28 degrees of timing and full transmission line pressure. Costs some coinage, but you will run faster, for a longer time.

Patrick G

iTrader: (14)

The performance difference between a stock screenless MAF and a calibrated 85mm MAF on a 400 rwhp LS1 was 0 rwhp (when I dyno tested both a few months ago). I was shocked, but the screenless stock unported MAF was not a flow restriction (and that's with a lid and a ported throttle body on each side of it too). If you make more than 400 rwhp, then the 85mm MAF is probably a help, but on my car it made 0 more rwhp.

mmiller

iTrader: (1)

Patrick,

Leave the partician / divider in the middle of the stock unported TB or cut it out?

Patrick G

iTrader: (14)

You want to leave the divider in the middle of the Mass Air Flow sensor, but I'm not sure what you mean about the Throttle Body. Porting the Throttle body is always a good thing...but the divider in the middle is the throttle plate and you need to keep that. <img src="gr_images/icons/wink.gif" border="0">

DanZ28

iTrader: (5)

Patrick, thanks for taking the time to post your experiences and knowledge about this subject. <img src="graemlins/gr_hail.gif" border="0" alt="[hail]" /> The stock ends are back on for now, and other than the idle relearn, I don't notice a difference (SOTP) between them anyway..

Dan

mmiller

iTrader: (1)

Sorry Patrick. I meant MAF.

Reboot

iTrader: (5)

I just removed my Granatelli and put my stock maf on. I lost alot of power but the shifts are much harder.

How can I get the best of both worlds? <img src="images/icons/confused.gif" border="0">

Patrick G

iTrader: (14)

The only way to get the best of both worlds is custom programming. This way, you get as much timing as you need, the ideal a/f ratio, and full line pressure for your tranny. Costs some change, but it will get it all for you.

The reason why you feel a power loss with your stock MAF is because your pcm is going to need quite a few miles before it re-learns your new combo. The power will return...or at least most of it.

LS1x2

iTrader: (11)

So, if I'm reading this right, you could lower the base setting on the MAFT and compensate the a4 line pressure problem with the hypertech shift firmness with no negative side affects?