Best place to put MAF on a boosted application?
06-29-2006, 11:29 PM
#1
Best place to put MAF on a boosted application? Was having a conversation with a friend about this subject. Would it be better to have the MAF on the inlet side of the turbine or before the throttle body?
I feel it should be before the throttle body since you're then reading true air volume the engine is getting, and not at the inlet of the turbine where you may have blowoff valves/regulators/etc. on the boosted pipes (venting to atm.) messing with the values that the PCM thinks the engine is actually getting. In the end, I know it's all about the tuning and making sure you don't have leaks/etc., but as far as setup goes which has proved/seems to be better?
Tried searching but couldn't fine anything on this subject.
I feel it should be before the throttle body since you're then reading true air volume the engine is getting, and not at the inlet of the turbine where you may have blowoff valves/regulators/etc. on the boosted pipes (venting to atm.) messing with the values that the PCM thinks the engine is actually getting. In the end, I know it's all about the tuning and making sure you don't have leaks/etc., but as far as setup goes which has proved/seems to be better?
Tried searching but couldn't fine anything on this subject.
06-29-2006, 11:45 PM
#3
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The best place for a MAF is before the TB and after the turbo pressure side. Somewhere in between the TB and the Intercooler if you have one. I also belive that a blow threw MAF is better then a suck threw. I think you get more of a accurate reading. Compresser surge can mess it up on a suck threw.
You will have to route your BOV discharge back into the system if your BOV is after your MAF. On my setups I put the BOV before the MAF. Then you can vent it out sense it will not be metered air yet. Another way is if your running SD. It doent matter what you do sense its not reading the air before it goes into the TB. Hope this helped
You will have to route your BOV discharge back into the system if your BOV is after your MAF. On my setups I put the BOV before the MAF. Then you can vent it out sense it will not be metered air yet. Another way is if your running SD. It doent matter what you do sense its not reading the air before it goes into the TB. Hope this helped
06-29-2006, 11:58 PM
#5
Originally Posted by tt427ls1
The best place for a MAF is before the TB and after the turbo pressure side. Somewhere in between the TB and the Intercooler if you have one. I also belive that a blow threw MAF is better then a suck threw. I think you get more of a accurate reading. Compresser surge can mess it up on a suck threw.
You will have to route your BOV discharge back into the system if your BOV is after your MAF. On my setups I put the BOV before the MAF. Then you can vent it out sense it will not be metered air yet. Another way is if your running SD. It doent matter what you do sense its not reading the air before it goes into the TB. Hope this helped
You will have to route your BOV discharge back into the system if your BOV is after your MAF. On my setups I put the BOV before the MAF. Then you can vent it out sense it will not be metered air yet. Another way is if your running SD. It doent matter what you do sense its not reading the air before it goes into the TB. Hope this helped
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07-01-2006, 09:55 AM
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Since a few of you said trash it, go SD, what do you do when the weather changes. IE. you tuned your car, it was 90-95* out with 85+% humidity and now its 70* out with 50% humidity or even lower 40* out with 50% or less humidity?
07-01-2006, 10:44 AM
#10
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I say ditch the MAF too. From everything Ive read, the MAF maxes out pretty fast and then its shooting in the dark. With SD and a custom OS, the engine always knows that air thats coming in. No guesses. Ive read that the IAT will adjust for the most part, but I could be wrong too.
07-01-2006, 03:48 PM
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Originally Posted by chuntington101
SD will be much more acurate and adjustable!
Chris.
Chris.
That I understand...but like I said up top...if you go from one extreme to the next, how does that effect your tune/power output? Do you have to make another tune for the other temp/humidity?
07-01-2006, 05:20 PM
#14
Originally Posted by DarkblueTA
Since a few of you said trash it, go SD, what do you do when the weather changes. IE. you tuned your car, it was 90-95* out with 85+% humidity and now its 70* out with 50% humidity or even lower 40* out with 50% or less humidity?
07-01-2006, 05:30 PM
#15
dosent effect much, maybe .1-.2 afr, more so on steady cruise, but thats w/ big temp differences, as far as wot, once the ve table is set you can just adjust the boost enrich and open loop afr, for driving, the hotter the leaner, but if you adjust your iat retard to take timing out w/high intake temps, it will equal out, (less timing the richer), you could get by on 2 tunes for a year, 2nd one only being more aggressive for race gas, also depends on what kind of driving you do, the longer your in a gear the richer the afr will be, and also if your engine is forged you can be a little more aggressive w/the tune.... I like to keep my low load cruise about 15:1 afr for mileage, but then drop down to 12.8 on a non boost load then go to 11.2 in boost.. I allways had problems w/the maf being inconsistant and throwing off a tune from day to day rather than maxing out, is why I ditched mine...
07-01-2006, 06:53 PM
#16
that it, you just put the nuumbers in the LUT's and then you can run what you like! it also means you can max out the performance at all rpm/boost/temp/timming etc etc
i dont see why more people dont use them. i kknow in the import market, standalone ecus are much more comon than what i have seen on here! why is that???
Chris
i dont see why more people dont use them. i kknow in the import market, standalone ecus are much more comon than what i have seen on here! why is that???
Chris
07-01-2006, 09:15 PM
#17
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Originally Posted by kbracing96
I've been running SD since last fall on my truck, which is my DD and I haven't had a problem with different temps. That's why the PCM uses IAT sensor and takes a baro reading at start-up, so it can compensate for different air temps. I have never had my tune go way off with changes in air temp or humidity, and I live in WY where is -20* i the winter and 100*+ in the summer. There are millions of cars that came from the factory with SD fuel injection, and they don't run like **** when the temp changes. If your worried about keeping everything dead on, and like to mess with you tune, EFILive and I think HPT has it to, but they have tables in there custom OS's to adjust for different air temps. I generally only change my tune when I make some sort of change to my setup. As far as weather, When I log BEN factor on my setup, they are generally .99 to 1.01. Pretty good in my book.
That's what I was thinking but wasn't 100% sure. Thanks for the confirmation. BTW, your sig kicks ***.
