New Delphi LS1 MAF design
Those of you who think de-screening your MAF increases power. What exactly are your MPH increases in 1/4 to backup your theory?
I'll bite on this. It may help smooth airflow but I dont believe this really detrimental as if you remove the screen. By removing the screen you allow much more airflow through the maf. Many tuners suggest removing it before the tune because they can correct for any small quirks that may come up in the process. Also if the screen is such an essential piece then why does NO new gm maf have one? Even the c5z06 maf doesnt have a screen
When you say "much more airflow"...how do you quantify "much more"...go take a car that's not really setup for drag racing...like not really really really dialed in, suspension chassis and drivetrain, for the strip, dial in the full throttle air/fuel, and go make 10 passes at the track...now remove the screen, re-correct the full throttle air/fuel to the exact same AFR, and go make 10 more passes at the track..."much more airflow" at the same AFR, would result in "much more" mph too...and much less ET assuming the newfound tremendous increase in power doesn't result in additional tire spin.
That said...if you average the before MPH and the after MPH, and throw out any timeslips that had excessive wheelspin over the other runs from both sets of data...I bet you'll see an incredibly insignificant difference in the vehicles MPH.
Now...as I said in a previous post on this thread...in a car that is really truly a track only drag car...nobody really cares about the extremely light throttle low airflow driving characteristics. In that case...the chassis is tweaked in correctly...the suspension is setup properly...and the tune in the engine is probably right on the hairy edge of safety (something NOBODY in their right mind does on a "street car"), in that case...sure, go ahead and yank the screen from the MAF...you know what though...yank the whole MAF...you CAN dial the AFR and spark advance in properly in speed density, and you can now remove the entire MAF internals from the air path...and you'll still only see a minor minor minor difference in the ET and MPH.
What makes you so sure that no new GM MAF has a screen? The C5 ZO6 has a different intake path than the LS1 F-Body. And, when the C5 ZO6 was designed, GM was willing to make sacrifices to the cars refinement in order to make it a more rough around the edges version of the Vette, that can attack a track better...even the new card style MAF sensors used in the C6, and new Camaro's and lots of other vehicles...are you sure there aren't screens somewhere in the intake path when necessary...there's a LOT more to an air intake than a MAF, a filter, and a filter location to breath air that's as close to outside air temp as possible. Depending on the structure of the entire intake path, sometimes a screen is more of a necessity than others.
I have a cold air intake on my 2010 Camaro SS that drastically changes the air flow path from stock. Stock the 5th gen breathed air from a box located on the drivers side of the engine bay, through a tube, through an elbow, and into the throttle body...my aftermarket cold air intake breathes from right behind the grille in the middle of the car, over the radiator, and into the throttle body...and it HAS a screen built into it.
That said, if you look at the typical bolt on's 5th gen Camaro SS, with a TR6060, stock gears, full weight, and normal add on's like long tube headers, cold air intakes (of various types, including many that breath from the stock location), exhaust work and tuning...my high 116.xx mph trap speeds without any wheel spin at all, at full weight, on stock 20" wheels, are just about as fast as it gets...in fact, I only know of 1 that traps 117 on the same wheel setup, 1 that traps 117 on lighter 18" wheels, and 1 that traps 119 on front skinnies, even lighter 17" rear wheels, and the addition of an underdrive pulley...so what exactly am I leaving on the table by ADDING a screen to my car with the intake I chose?
...on and by the way, my car drives as smooth as glass...in ALL situations...I can let it idle in gear, on flat pavement, up an incline, down an incline...it'll just move very very very smoothly at all of 550 rpm, clutch fully engaged, my foot not touching the throttle at all...with a 100% stock spark advance table, no tricks in the PCM at all...just a MAF sensor cal that is dialed in as tight as I could dial it in, and speed density cal that is also as tight as I could get it, and allowing the GM algorithm to blend SD and MAF as it chooses to in the background.
The C5Z obviously didn't have the screen but if you look at the placement of the MAF, it is much much further away from the blade and has to go through the bridge before it goes into the TB area, that in itself straightens the airflow out on that particular setup. So like stated above each intake tract is different and has to be looked at accordingly.
Having a dyno if people really want to see the difference and someone is willing to ship me a screenless MAF to test I will be more than happy to show dyno comparisons. I have stock Fbody MAF's with the screens still and also have a couple of 85mm MAF with screen still also. So either or will work. If I run across one here at the shop that doesn't have a screen anymore I will test also.
My cold air intake, as I said above, has a screen in it. It also has been replaced by the manufacturer due to a cosmetic issue on the outside, and they told me to just toss the original out, they don't need it.
That said...I guess I can gut the screen from the one with the cosmetic issue, drive around in a surging car with O2 sensors trying to correct for crappy airflow through the MAF, and see what she does on the dyno...then put the one with the screen back in, be thrilled with the smooth driving, and make another pull.
Maybe I will, I bet I'll see the same difference doing that as I'll see just making 3 pulls, walking away, walking back and making 3 more pulls.
Back on the MAF... does it have a larger opening than the original LS1 MAF's? I can't find dimensions on the new MAF posted.
When you say "much more airflow"...how do you quantify "much more"...go take a car that's not really setup for drag racing...like not really really really dialed in, suspension chassis and drivetrain, for the strip, dial in the full throttle air/fuel, and go make 10 passes at the track...now remove the screen, re-correct the full throttle air/fuel to the exact same AFR, and go make 10 more passes at the track..."much more airflow" at the same AFR, would result in "much more" mph too...and much less ET assuming the newfound tremendous increase in power doesn't result in additional tire spin.
That said...if you average the before MPH and the after MPH, and throw out any timeslips that had excessive wheelspin over the other runs from both sets of data...I bet you'll see an incredibly insignificant difference in the vehicles MPH.
Now...as I said in a previous post on this thread...in a car that is really truly a track only drag car...nobody really cares about the extremely light throttle low airflow driving characteristics. In that case...the chassis is tweaked in correctly...the suspension is setup properly...and the tune in the engine is probably right on the hairy edge of safety (something NOBODY in their right mind does on a "street car"), in that case...sure, go ahead and yank the screen from the MAF...you know what though...yank the whole MAF...you CAN dial the AFR and spark advance in properly in speed density, and you can now remove the entire MAF internals from the air path...and you'll still only see a minor minor minor difference in the ET and MPH.
What makes you so sure that no new GM MAF has a screen? The C5 ZO6 has a different intake path than the LS1 F-Body. And, when the C5 ZO6 was designed, GM was willing to make sacrifices to the cars refinement in order to make it a more rough around the edges version of the Vette, that can attack a track better...even the new card style MAF sensors used in the C6, and new Camaro's and lots of other vehicles...are you sure there aren't screens somewhere in the intake path when necessary...there's a LOT more to an air intake than a MAF, a filter, and a filter location to breath air that's as close to outside air temp as possible. Depending on the structure of the entire intake path, sometimes a screen is more of a necessity than others.
I have a cold air intake on my 2010 Camaro SS that drastically changes the air flow path from stock. Stock the 5th gen breathed air from a box located on the drivers side of the engine bay, through a tube, through an elbow, and into the throttle body...my aftermarket cold air intake breathes from right behind the grille in the middle of the car, over the radiator, and into the throttle body...and it HAS a screen built into it.
That said, if you look at the typical bolt on's 5th gen Camaro SS, with a TR6060, stock gears, full weight, and normal add on's like long tube headers, cold air intakes (of various types, including many that breath from the stock location), exhaust work and tuning...my high 116.xx mph trap speeds without any wheel spin at all, at full weight, on stock 20" wheels, are just about as fast as it gets...in fact, I only know of 1 that traps 117 on the same wheel setup, 1 that traps 117 on lighter 18" wheels, and 1 that traps 119 on front skinnies, even lighter 17" rear wheels, and the addition of an underdrive pulley...so what exactly am I leaving on the table by ADDING a screen to my car with the intake I chose?
...on and by the way, my car drives as smooth as glass...in ALL situations...I can let it idle in gear, on flat pavement, up an incline, down an incline...it'll just move very very very smoothly at all of 550 rpm, clutch fully engaged, my foot not touching the throttle at all...with a 100% stock spark advance table, no tricks in the PCM at all...just a MAF sensor cal that is dialed in as tight as I could dial it in, and speed density cal that is also as tight as I could get it, and allowing the GM algorithm to blend SD and MAF as it chooses to in the background.
http://www.saxonpc.com/100mm-cells-for-100.html
The C5Z obviously didn't have the screen but if you look at the placement of the MAF, it is much much further away from the blade and has to go through the bridge before it goes into the TB area, that in itself straightens the airflow out on that particular setup. So like stated above each intake tract is different and has to be looked at accordingly.
Having a dyno if people really want to see the difference and someone is willing to ship me a screenless MAF to test I will be more than happy to show dyno comparisons. I have stock Fbody MAF's with the screens still and also have a couple of 85mm MAF with screen still also. So either or will work. If I run across one here at the shop that doesn't have a screen anymore I will test also.
Post up your Logs and configs when doing so.
Too much bad information floating around the internet... Shocking huh?
Last edited by The1N_only; Feb 27, 2012 at 11:39 PM.
The Best V8 Stories One Small Block at Time
(there was also the one showing smoke trails ("flux lines") getting straightened inside a box by the honeycomb, but I can't find this video).
http://www.youtube.com/watch?v=Xb6ANasThB0
http://www.youtube.com/watch?v=KNExOgtLt2w
Post up your Logs and configs when doing so.
Too much bad information floating around the internet... Shocking huh?
Last edited by NEokcTERROR; Feb 28, 2012 at 11:15 AM. Reason: Punctuation
I assume you do this as a living as well as myself. I have wasted hours upon hours on my own LS stuff just seeing exactly what little wierd things like this do. You would be correct in that the PCM views the MAF report "x" times per second no matter how erratic it may be, but the computing power would have to increase to handle the irregularities. The MAF is in the utmost foreground processes of the processor where total attention is a priority, unlike say canister purge monitoring or tank pressure etc. This stuff is prioritized in underlying code of everything electronically controlled.
I am not saying the 411 or E38 etc. is not capable of even more than it will ever see. Just thinking a little outside, and am sure it's a non-issue for the most part.
I put a saxon straightener in all the cars I see that have moderately erratic and worse MAF logs. It helps part thottle and idle tremendously and for the most part hinders performance only slightly if even at all.
and it seems that the PCM can't handle larger squiggles as can be seen by fueling diverging.
http://www.saxonpc.com/100mm-cells-for-100.html
Post up your Logs and configs when doing so.
Too much bad information floating around the internet... Shocking huh?
and it seems that the PCM can't handle larger squiggles as can be seen by fueling diverging.
Regardless...anyone who blindly says "remove the screen, then run this other cars MAF table" without knowing anything about the intake path on the car, the cam in the engine or anything else...sketchy.
BTW I don't understand how people justify the headaches associated with descreening a MAF for gain of a 1/10 th of 1 horsepower. Each to his own but you won't feel the difference and you most likely won't see an ET drop.
If you wanted to (unless they're modifying and removing the IAT in the sensor, which I doubt), you could just buy the correct matching connector, then remove your original IAT and MAF connectors from your vehicle, run all 5 wires as 1 "harness" to the new sensor, and pin them accordingly (should be Delphi GT 150 series) and have what I guess would be a cleaner look.







