1 Bar Maf tuning a 2 bar situation

[shimp]

Thanks for that explanation. So even though some people do it with MAF, it's always more accurate to go SD with a bigger MAP sensor?

[redhardsupra]

yes, no limits that we bumped into yet even with the 3bar MAP

[alanderson1978]

the good part about voltage based MAF's that it's easy to multiply/divide voltage. frequency based MAFs are more precise, but the whole idea of multiplying/dividing the range goes out of the window, unless you figure out a circuit that can multiply frequencies.

the reason why some cars deal with a lot of power on MAF is the voltage trick. for example, if your MAF describes 500g/sec at 5volts, and at that moment you'll be doing 20ms pulse width on your Xg/sec flowing injectors, you can cut the MAF voltage in two, while sizing your injectors to flow 2*X.
so at 2.5v computer thinks you're flowing 250g/sec of air, which needs X/2g/sec of fuel. but in reality you are flowing 500g/sec at 2.5v, and your injectors are dumping twice what X/2 would be, which is X. so you're back to the same air/fuel amounts (500g/sec and X fuel, just like in the starting case) but at 2.5 volts, not 5.

this way at 5v computer thinks that it's flowing 500g/sec and needs X fuel. in reality it's flowing 1000g/sec of airflow, and injectors will dump 2*X fuel, keeping AFR the same. so you end up with twice the range on the same voltage range.

this theory goes out the window when things go nonlinear, and since very few things in reality are linear, this method is plagued with assumptions and fudge factors. in the end to have a proper tune you'd have to make up for the imprecision somewhere else, and that's why i'd rather do things right from the getgo--if both methods will ultimately take the same amount of work, but one of them is going to be working off wrong numbers, might as well do it proper.

That would make sense. The Duramax uses a 0-5 volt MAF and stock makes about 19 psi boost, and I've heard some go as high as 30-32 psi on the stock turbo, still using the MAF.

I wish I knew as much about anything as you do about tuning

Could you practically go to SD on a diesel?

[Black04A4]

Here is the P/N:
AC Delco Part # 213-1631
GM Part #: 12580698

And the pigtail connector (if necessary):
AC Delco Part # PT1799

Are these part numbers the same for the LS1? I'm about to install a Procharger on my '04 GTO and would like to have all the extra parts together when the kit arrives.

[EC_Tune]

Yes, All LS1/LS2/LS4/LS6/LS7/LQ4/LQ9/LM7/LR4/LM4 motors.

[Charles]

Sorry to bump this up. What are people doing on 98's where there is only a 2 bar option when you are running more then 15 psi?

[twinturbo]

That would make sense. The Duramax uses a 0-5 volt MAF and stock makes about 19 psi boost, and I've heard some go as high as 30-32 psi on the stock turbo, still using the MAF.

I wish I knew as much about anything as you do about tuning

Could you practically go to SD on a diesel?

No reason to on your duramax, nor is it necessary on a ford. I've run 35-40psi and not had a problem on either.

The dc voltage meters are either put into a larger tube (less concentration of air on the hot wire), or a voltage divider is used (may be done internally to the maf).

jim

[JoshuaGrooms83]

not to dig up an old thread but im new to hptuners and wanted to make sure im doing stuff right. I have a 98 TA with a 98PCM tuned by frost previously. I know 98 PCMs are the redheaded step children that most dont like to discuss lol
im curious, can i tune my car with a MAF and a 2bar MAP without using Speed density with 15psi tuned into it? (this will be my "safety" zone for boost spikes and creeps just in case but 10psi will be my running physical limit by wastegate spring)

[hiperf454]

So what is the part number for a 2 bar for an 03 LS6 that will plug in? If I can get the thing to recognize my car again I will go that route. Im at 10lbs and I am chasing my fuel tail just like described by Bill. So If this thing will work again I will do it. I do need the part number for the 2 bar Map.
Thanks
Kelly

[blownbluez06]

12615136 replaced old part# 12580698 also 16235939 and 09350899 you may have to grind ears off one side. No biggie.

[HartRod]

I have a 2006 59 computer and I'm confused on this. If you apply the 2 Bar MAP OS, are you forced to do a SD tune? Is the MAF no longer relevant?

Stock 5.3 engine with a MP112 Magnacharger and a OEM 2 Bar MAP sensor.

[Jason.Henley]

Not sure if this is listed as a con to using the MAF.
But the experiences that I have with 4 separate new sensors is they don?t remain in one piece under boost.