Yes I agree.. not to beat a dead horse... but here is my experience and opinion: 1) MAF I found easier to tune on a STOCK motor. 2) Motor made more power with it on, but 3" abs had same effect, makes me think for MY setup, that intake tract and size can change performance.. might have something to do with velocity or air is increased ad straitened.... Lessening the pulsing effect or helping the resonance part of the tpi intake....?? Any ideas.. 3) When mafs go south $$$$ 4) I got frusterated trying to make the maf work so I converted to 730 5) Why is all ford maf great.. map garbage??? 1) 730 seems to be better ecm... more reliable.. Faster??? 2) Takes bigger eprom 3) More options in the code for driveability.. ie highway mode spark.. low octane fuel ect ect 4) Map takes a little more for beginner to tune.. can screw things up easy. 5) Cheaper by far...ecm are more common to find But I still have friends that are running maf on stock motor...I tune there cars for kicks and experience, they think maf better more accurate ect ect stubborn and ignorant.. ya da ya da.. If you people knew the ideas and projects iv'e been trying, youde laugh.. but I just want to see if it can be done :-)... like trying to run map on 730 and use the maf as well....it sort of works but still problems.. the advantage? None that I can see. He he... Sort of the same as why would you want your car to be able to use more than 1 ecm?? ;) Mike Rolica Plant A, Magnesium Products Division Strathroy (519)-245-4040 Ext. 265 -----Original Message----- From: Bruce Plecan [SMTP:nacelp@bright.net] Sent: Tuesday, June 20, 2000 8:01 PM To: gmecm@diy-efi.org Subject: Re: Changing 165 / Nother Q The porting shouldn't really effect much of anything having to do with the O2, IMHO. The flow at idle is like 10ish grms/sec., vs 255 at WOT. I'd guess that at less then 100 grms/ sec your at a high enough TPS to be in PE. If a fuel pressure corrected anything it was the disturbed air flow and inaccurate reading from the MAF. Put another notch in the belt for modified engines and MAP. Two wrongs don't make a right here either, with the info here, I just can't see why not just do it right the first time. For all the time dinkin with the MAF you've wasted the only advantage it had. As a tuning tool like Scott S is using it great, but I still ain't sold on it being the ultra setup, when you run out of resolution with it. Grumpy > If mine pegged I'd have a problem.. it does NOT peg (yet). > > If a gutted MAF was done at the same time as a FP increase, o2 and thus > BLM's may stay in balance. What you have then is an incorrect air reading > as well as an incorrect fuel reading, both incorret by the same proportion, > in the same direction, the net result is "it runs pretty darn good". (did I > get that right?) > > The more retentive tuning guys go nutz over this. Yes I would go nutz over > it if I thought I knew what I was doing more, then I could make it right, > but good 'nuff seems to be the order of my ways. ;-) > > I was out to try some fancy stuff with a 'holy' MAF, but the supercharger > crapped out and I never followed thru. add it to the list of good > intentions fallen flat. > > ----- Original Message ----- > From: Mike Rolica <mrolica@meridian-mag.com> > To: <gmecm@diy-efi.org> > Sent: Tuesday, June 20, 2000 11:33 AM > Subject: RE: Changing 165 / Nother Q > > > > or how bout a EEEEEEK ford one :) > > > > -----Original Message----- > > From: Romans, Mark [mailto:romans@starstream.net] > > Sent: Saturday, June 17, 2000 12:41 PM > > To: gmecm@diy-efi.org > > Subject: Re: Changing 165 / Nother Q > > > > > > Dave: I have a ported maf on my Vet. I have had to adjust the > calibration > > only in the smallest calibration table. BL has stayed close to 128 at all > > other areas so I am assuming that the calibration has not been thrown off. > > The problem is once again in that the software doesn't read above 255 > > grams/sec. > > I have thought about, but taken no action on looking at the Porsche 928 > > bosch maf sensor. It is supposed to have a larger ID and flow more air. > I > > would attempt to adjust the injector constants to make fuel match up with > > air flow. I would lose some accuracy, but it would be no different than > > what the 730 does. > > Mark > > > > ----- Original Message ----- > > From: "Dave Zug" <dzug@delanet.com> > > To: <gmecm@diy-efi.org> > > Sent: Saturday, June 17, 2000 1:07 AM > > Subject: Re: Changing 165 / Nother Q > > > > > > 400000000000000000 / 256 = 156250000000000 (close) G/S per single unit of > > resolution on the sensor.... > > > > Your point is understood, but I'd use MAP for the jet engine ;-) > > > > converting to 16 bit would be useful only if the sensor range was also > > raised. If you turn an 8 bit value into a 16 bit, it just gives you the > > ability to see the sensor value as more tiny-er steps... not higher > values. > > you would have to change the sensor range at the same time to be able to > > read more air. (9 bits will get you to 512 steps, BTW). sorry this may > be > > out-of-place rambling, I don't understand how this is done very easily. IN > > the code, the A2D would see a maxxed input, translate to FFh, and that may > > trigger some creative code to say "go to the high table" but the input > still > > will be pegged. you'd almost have to electronically reduce (re-scale) the > > voltage input from the MAF to the ECM, then allow the internal 9-bit (16 > > bit) value to read 255 when the voltage level was at 4v or something, > then > > have the internal 9-bit read 320 at 5v... a second "high" table would have > > entries that were up to (320 minus 255), and would be in use only when the > > "high flow" bit (9th) was lit. > > > > oooh my brain, the POOR '165 ;-) Please, as always... someone add / > > correct me so I don't confuse others browsing the archives. > > > > I have used the RPM based fuel tweak to compensate for what the MAF can't > > see. Its a trial and error method, but I got it to work out when I had > the > > Supercharger on. I started reeeal rich, and used o2 to make sure I wasn't > > lean, but I should have backed it up with an EGT. > > > > Makes sense to me that if you can increase the size of the MAF (not saying > > anything new here) that the readout for a given flow rate will decrease > > exactly proportionally with the increase in orifice area. the big job is > to > > go thru EVERY calculated value (on chip) and every comparison made to > those > > values, and adjust them accordingly. i.e. trip into PE mode at a MAF > value > > of 40(d) insted of 55(d) because now 40 represents 55 g/s and 255 > represents > > 320 g/s (or whatever math...) > > > > To MY Question: > > > > Has anyone scientifically measured the effect on readings between an > > unported, stock, screened MAF and a ported (no sink) and un-screened MAF? > I > > figgered roughly the percentage of area opened up, and a little tweak for > > the reduction in air turbulance and went with that to re-calibrate the MAF > > tables. I figgered a shop vac and a y-pipe and a volts meter would give a > > ratio as well. anyone done it? share? of coarse the voltage reading > will > > be lower for the gutted MAF, but it would be cool to have a graph of each > > at all flow levels ;-)) > > > > > > > > ----- Original Message ----- > > From: Mike Rolica <mrolica@meridian-mag.com> > > To: <gmecm@diy-efi.org> > > Sent: Thursday, June 15, 2000 1:05 PM > > Subject: RE: Changing 165 fuel delivery was "General tuning question - > fuel > > economy" > > > > > > Argggg.. yes it can pull in 40000000000000000000times more air but as > long > > as you are in the range of the maf... ie below it's max sensing cap ie 254 > > g/s then the maf is fine. > > > > Senario 2.. lets say at 2500rpm and ½ throttle, and you are pulling > 255g/s > > then the ecm thinks this is max air it can get....so it cant regognize and > > more air.... That is why I would like to create a patch to use either 2 > > tables or go 16 bit!!!! > > > > > > <BIGSNIP> > > > > -------------------------------------------------------------------------- > -- > > To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes) > > in the body of a message (not the subject) to majordomo@lists.diy-efi.org > > > > > > -------------------------------------------------------------------------- > -- > > To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes) > > in the body of a message (not the subject) to majordomo@lists.diy-efi.org > > > > ----- End of forwarded message from owner-gmecm@diy-efi.org ----- > -------------------------------------------------------------------------- -- > To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes) > in the body of a message (not the subject) to majordomo@lists.diy-efi.org > > ---------------------------------------------------------------------------- To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes) in the body of a message (not the subject) to majordomo@lists.diy-efi.org
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