IHADAV8.com - Turbo Buick Tech, and Nonsense
Tech Area => General Buick Tech => Topic started by: daveismissing on November 07 2017, 01:52:22 PM
-
Are there any of currently available MAFs preferred over others (LT1 vs LS-whatevers etc)
Plastic ones OK?
-
The last 1 I got was off a rendezvous 3 in. Didn't you have 1 of those? anyway $50 Ca at the yard
-
Delphi are prolly best? I have a plastic Z06 I picked up from Dave (IKWIK6) years ago. No idea of the brand.
-
The last 1 I got was off a rendezvous 3 in. Didn't you have 1 of those? anyway $50 Ca at the yard
When I towed it into the dealer as a trade-in he might have complained if I then pulled the MAF off in the lot?
:)
-
LS3/7 blade style with a laminar airflow straightener.
I can get into why I believe all of this SD3.14 chip stuff isn't a good enough solution.
EDIT (1st intermission on the Devils game)...
My concerns are two-fold:
1. Speed Density is too touchy based upon environmental variables which can knock a tune out of spec enough to exhibit issues. The old Buick-type ECMs lack a lot of fidelity from cell to cell which further exacerbates this issue. Hell, in a late model ECM it still is pretty wonky with four times as many cells.
2. MAFs and Translators are just a guess at fueling using a meter that isn't calibrated for the engine it is stuck on; and without the means to adapt it. A MAF needs to be mapped to the engine it is attached to, especially in an open loop application.
Both my Procharged TBSS' 6.0L LS2 and N/A 5.7L LS1 in the wagon run the same LS3/7 blade-style MAF (capable of reading up to 15,000Hz and about 950g/s of air flow) in a 4" tube with a large cell honeycomb air straightener. Both are high RPM capable engines with good volumetric efficiency (outside of boost)
The TBSS pulls the following numbers under load:
2,350rpm - 136g/s @ 6,722Hz = 0 psi
3,900rpm - 216g/s @ 8,171Hz = 4.8psi
5,300rpm - 349g/s @ 9,685Hz = 8.2psi
6,600rpm - 530g/s @ 10,925Hz = 12psi
The Wagon pulls the following numbers at the same load points:
2,380rpm - 98g/s @ 4,942Hz = 0 psi (cam makes it lazy down low)
3,900rpm - 188g/s @ 6,683Hz = 0 psi
5,300rpm - 287g/s @ 7,619Hz = 0 psi
6,500rpm - 350g/s @ 8,120Hz = 0 psi
Note the RPM and Hz points at which both sensors see 350g/s - as you can imagine the curve in the TBSS is a lot longer and smoother than the wagon's. This shows the versatility of the sensor. Truth be told the wagon really should have it's sensor in a 3" or 3.5" tube to improve resolution and driveability (meaning it would likely lengthen the curve and carry it to a higher frequency).
Which brings me to my absolute disgust at how these things have been handed out to Buick owners as a one-size fits all solution to the factory MAF. Unless you have a wideband and a means for collecting the Equivalence Error the LT1/LS1/LS6 sensors installed they are not as effective as they should be. Granted you still have your INT/BLM (short and long term) to trim the fuel under closed loop conditions to compensate for this in the ECM, and the High/Mid/Low fuel adjustments in a Translator to roughly drag the curve back into spec. Ultimately the user has no control over the MAF and cannot fix the error - and this is a huge disservice to the Buick community. Every change you make to your engine moves you further away from an accurate reading (heads, cam, turbo, exhaust, air filter... and yes the intake tube size too).
In conclusion: Ultimately there should be some serious effort put into running a hybrid (MAF/VE) system like it came from the factory, only adding closed loop correction at WOT.
-
Food for thought - the data points are enlightening. Thank You
-
Ive never seen anyone disagree with him. How much does it cost to get the ball rolling? Lets do this!
-
Michael.
You are correct but you spelled trim wrong. :icon_fU:
Great thought out post that makes sense.
-
Brad, For what it's worth........T hat 85mm (Z-06) MAF sensor you have is infact a Delphi brand.
I'm still running one too and has been faultless for over 5 the years it's been installed . :023:
-
Michael.
You are correct but you spelled trim wrong. :icon_fU:
Great thought out post that makes sense.
Sorry... the game came back on and I got distracted. ;)
-
Brad, For what it's worth........T hat 85mm (Z-06) MAF sensor you have is infact a Delphi brand.
I'm still running one too and has been faultless for over 5 the years it's been installed . :023:
Sounds good...thanks. I'll have to grab the part number off it.
-
https://www.turbobuick.com/threads/maf-sensor-frequency-vs-gps-airflow-table.196197/ (https://www.turbobuick.com/threads/maf-sensor-frequency-vs-gps-airflow-table.196197/)
Found this while taking a break. So yeah, essentially we are comparing a calculator watch to a smartphone interms of the capabilty of sensors and ECMs. It is incredible how muchna Translator has to dumb down the signal for a stock ECM (notwithstandin g code rewrites in the chip).
-
Party like it is 1999: http://www.wellsve.com/sft503/counterp_v3_i2_1999.pdf (http://www.wellsve.com/sft503/counterp_v3_i2_1999.pdf)
Confirms the frequency range and flow limitations of the stock system.
http://www.turbobuicks.com/forums/#/topics/48699?page=2 (http://www.turbobuicks.com/forums/#/topics/48699?page=2)
-
my 3.5" LS1 sensor is 89872981785 Delco 3 wire - 4" TBSS sensor 25168491 Delphi 5 wire
-
Party like it is 1999: http://www.wellsve.com/sft503/counterp_v3_i2_1999.pdf (http://www.wellsve.com/sft503/counterp_v3_i2_1999.pdf)
Confirms the frequency range and flow limitations of the stock system.
http://www.turbobuicks.com/forums/#/topics/48699?page=2 (http://www.turbobuicks.com/forums/#/topics/48699?page=2)
linky no workie
-
Carl: The stock maf was pretty temperature sensitive, so much so that buick added the manifold temperature sensor (yes, I know they put it in the air filter and not the manifold but they called it a mat) and only used it for maf correction.
sigh
-
Party like it is 1999: http://www.wellsve.com/sft503/counterp_v3_i2_1999.pdf (http://www.wellsve.com/sft503/counterp_v3_i2_1999.pdf)
Confirms the frequency range and flow limitations of the stock system.
http://www.turbobuicks.com/forums/#/topics/48699?page=2 (http://www.turbobuicks.com/forums/#/topics/48699?page=2)
linky no workie
http://www.turbobuicks.com/forums/showthread.php?t=48699 (http://www.turbobuicks.com/forums/showthread.php?t=48699)
-
Thanks Earl- ah yes, our former forum host mocking the MAF tap test.
I'll choose to believe Ken Mosher and my own experiences.
-
I'm sure clear silicone played a part in there some where
-
Ah fuck... I was mobile when I posted that link - the phone's owner does stupid shit from time to time.
-
Thanks Earl- ah yes, our former forum host mocking the MAF tap test.
I'll choose to believe Ken Mosher and my own experiences.
The problem with the Tap test is that most folks hit it to hard. If it isn't bad before the tap it is often afterwards.
-
I always thought it odd to beat hell out of a sensor to 'test' it.
Then again if it's really close to failure, I'd much rather finish it off in my driveway than out in the wild. One is an irritation, the other is a wrecker bill. (and I'd rather buy a translator than pay for a wrecker)
Yet another reason stock MAFs belong in a museum instead of under the hood.