Thinking about descreening your MAF? Think again...
07-05-2006, 10:52 AM
#21
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Originally Posted by NicD
Are you ignoring my post above on purpose? For accurate results you have to have a calibrated MAF table before and after screen removal. I have been doing this for 5+ years now and I have plenty of datalogs showing an accurate jump in airflow and vacuum reduction in the intake manifold at WOT along with dynos showing 5-10 rwhp more depending on the combo. If this isn't conclusive nothing ever will be for you. But like others have said you have your mind made up so go ahead and leave your maf screen in and continue on your way. But just stop trying to preach to the choir, it's old.
I'm well aware of the fact that you need to calibrate it to the new VE when you pull the screen. And I have done that. The entire point was to show that with the screen pulled it's a complete crapshoot to get the sensor to read accurately.
07-05-2006, 10:59 AM
#23
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Originally Posted by Alvin
Check to make sure you don't have a tornado in front of your MAF 
Of course, it also lost power that it desperately needed...
07-05-2006, 11:00 AM
#24
Originally Posted by ChevyThunder17
The entire point was to show that with the screen pulled it's a complete crapshoot to get the sensor to read accurately.
07-05-2006, 11:12 AM
#25
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Originally Posted by NicD
Haha, people that have been doing this for a while are laughing at you right now with that sentence.
07-05-2006, 11:15 AM
#26
Originally Posted by ChevyThunder17
And let me guess, you are one of the people that have been doing this for awhile, right?
There are plenty of hot wire MAFs, GM or otherwise, that do not have a screen from the factory.
Simply stated, if you see a loss of performance from a descreened MAF, then you havnt recalibrated the MAF correctly / well enough IMO.
07-05-2006, 11:20 AM
#27
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I didn't see a loss in performance persay, just odd readings without the screen being in.
When I was testing it, the car was in SD mode. That's what you'd be logging in order to determine the g/sec without interference from the MAF. The MAF frequency jumps all over the place (compared to what the engine is taking in) without the screen. That data is what you would use to recal the sensor.
When I was testing it, the car was in SD mode. That's what you'd be logging in order to determine the g/sec without interference from the MAF. The MAF frequency jumps all over the place (compared to what the engine is taking in) without the screen. That data is what you would use to recal the sensor.
07-05-2006, 12:00 PM
#30
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I descreened the MAF on my 01 Z06, only thing I noticed on the scan tool was the fuel trims changed a little bit. The PCM was learning to operate without the screen in place.
If you know how to tune pretty good, you can tune a car with a Ported/descreened MAF to operate just like stock.
If you descreen and port your stock MAF sensor your allowing more air to enter into the engine at any given velocity. However the MAF sensors ability to measure air has not changed at all so you must TELL the PCM more air is entering then its measuring.
Example: your OEM MAF will flow 12gm air/sec at idle at XX velocity. A ported & descreened OEM MAF will flow 12 gm air/sec at ide but the Velocity will be XX minus ~10%. So the oem ported maf is actually flowing more air but its reporting less then is actually entering since the velocity for any given RPM range is lower then if hte MAF was stock/untouched.
The fix to this is to increase your entire MAF table by ~7-15% depending on how far your LTFT's are off. Once you do this then you can start your VE tune and then tweak the MAF a little more if required to be inline with your VE table.
If you know how to tune pretty good, you can tune a car with a Ported/descreened MAF to operate just like stock.
If you descreen and port your stock MAF sensor your allowing more air to enter into the engine at any given velocity. However the MAF sensors ability to measure air has not changed at all so you must TELL the PCM more air is entering then its measuring.
Example: your OEM MAF will flow 12gm air/sec at idle at XX velocity. A ported & descreened OEM MAF will flow 12 gm air/sec at ide but the Velocity will be XX minus ~10%. So the oem ported maf is actually flowing more air but its reporting less then is actually entering since the velocity for any given RPM range is lower then if hte MAF was stock/untouched.
The fix to this is to increase your entire MAF table by ~7-15% depending on how far your LTFT's are off. Once you do this then you can start your VE tune and then tweak the MAF a little more if required to be inline with your VE table.
07-05-2006, 12:02 PM
#31
Originally Posted by ChevyThunder17
If you have data, post it up. I'd like to look at it for comparison.
07-05-2006, 08:58 PM
#32
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Who the f**k really cares! Everyone has their own opinion and results will always vary. If you like the damn MAF screen, then leave it on. Lets stop all the 
-just get an SD tune and throw the damn MAF in the garbage
-just get an SD tune and throw the damn MAF in the garbage
07-05-2006, 09:16 PM
#33
if the screens are so important why did GM delete them for the 02+ Z06's ?...they may play more of a role with the factory air silencers installed, i'm sure the turbulence they induce is pretty significant, but without them i dont think they're that big a deal......my $.02
07-05-2006, 09:18 PM
#34
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Originally Posted by NicD
Haha, sorry I am not going fuel your fire. If you want to make a point you will have to post up your own. I personally don't care to further this pointless arguement that has been beat to death. And with that I am done with this non-sense but thanks for my daily laugh.
Dave88z, I'm on the verge of it. My results suck. I'm certain there are others that have had the issue. Perhaps SD will work for me.
Tripinaz, the sensor doesn't read consistantly without the screen. Whatever is going on in there, it's just not right. It'll read a varied amounts of air; i.e. at 4500 Hz it'll read a given range that varies up to 40% from the high to low point. You can calibrate for an average range, but it's still going to be way off from the Primary VE table. Unless I'm missing a crucial step...
07-05-2006, 09:20 PM
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Originally Posted by oange ss
if the screens are so important why did GM delete them for the 02+ Z06's ?...they may play more of a role with the factory air silencers installed, i'm sure the turbulence they induce is pretty significant, but without them i dont think they're that big a deal......my $.02
07-05-2006, 09:25 PM
#37
power i'm assuming, factory doesnt change emission related components unless they need to.....same design theory it seems, Vette intake tract is just longer....by the way i'm not tryin to bust your *****, just lurkin
Last edited by oange ss; 07-05-2006 at 11:43 PM.
07-05-2006, 09:26 PM
#38
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Originally Posted by oange ss
power i'm assuming, factory doesnt change emission related components unless the need to.....same design theory it seems... Vette intact tract is just longer....by the way i'm not tryin to bust your *****, just lurkin
I hear ya, I appreciate the feedback...
07-05-2006, 09:31 PM
#39
Originally Posted by txhorns281
let's just stop arguing about last year's (and the year before, and the year before) hot topic... ok? ok? ..... ok! 
Next hater post, and this one goes dead
Next hater post, and this one goes dead
07-05-2006, 09:54 PM
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Originally Posted by oange ss
not everybody sees every thread made by a member, i know similar subjects have been brought up before, but a little technical discussion to stir the noodle isnt gonna hurt anybody...nobody has control over the jackasses that join in
If people are going to offer rational, reasonable, and concrete responses, may this thread go on till the end of time. If people are going to argue (yes there is a big difference b/w argue and discuss), then we'll finish it now. Otherwise, yes, this has been a very hot topic over the years, my comment was for us "not to argue/be ugly about it" as opposed to discuss it.