Will I need to upgrade my MAF?
12-18-2009, 05:41 PM
#11
2nd Gear Member
Thread Starter
Join Date: Feb 2008
Location: Boston MA
Posts: 383
not sure of the size of the CAI pipe, its just the BBK one from american muscle
http://www.americanmuscle.com/bbk-co...e-96-04gt.html
.
http://www.americanmuscle.com/bbk-co...e-96-04gt.html
.
12-18-2009, 09:23 PM
#12
3rd Gear Member
Join Date: Apr 2007
Location: Georgia
Posts: 931
My bbk intake bolted right up to my lightning maf. I'd upgrade to atleast 24lb. injectors and maybe bump pressure up if needed.On a side note I actually had to grind the bolt flange off the maf and intake tube and put a coupler and clamp on them because the gasket kept blowing out and creating a boost leak.
12-18-2009, 11:04 PM
#13
4th Gear Member
Join Date: Nov 2009
Location: Canton, Michigan
Posts: 1,246
I disagree I can see him needed at least 24lbs injectors. And it's not his MAF that needs calibration, it's the EEC. The MAF reads the same airflow, it's just how the computer interrupts it that will change.
What size pipe is your CAI? If it's a 3" stick with the stock MAF and get a MAFIA if you need it. If it's a 4" pipe, just buy a Lightning 90mm MAF and call it a day.
What size pipe is your CAI? If it's a 3" stick with the stock MAF and get a MAFIA if you need it. If it's a 4" pipe, just buy a Lightning 90mm MAF and call it a day.
12-19-2009, 07:22 AM
#14
TECH SAVANT
Join Date: Dec 2006
Location: Saint Augustine, FL
Posts: 10,938
The stock MAF pegs (4.99V output) at around 3000 lb/h air flow. Leave some headroom, and at 4.8V your looking at 2700 lb/h.
At 12.5:1 AFR (a good place to be for n/a) that 2700 lb/h of air will need 216 lb/h of fuel to go with it. 216 lb/h of fuel, at 95% VE (Volumetric Efficiency), and 0.5 BSFC (Brake Specific Fuel Consumption) will support (216 / 0.5) * 0.95 = 410 HP.
Meaning that in the real world it (the OEM 80mm MAF) is solidly good to 390 to 400 flywheel HP--340 or so at the wheels.
Please keep in mind that these are "rule of thumb" type formulas good for establishing starting points, not absolute real world performance calculations...
Also, to reinforce what others have said, on EEC-V ("eek-5") and newer systems you do not need, nor should you seek out, a so-called "calibrated" MAF. You just buy a MAF and program that MAFs transfer function in to your tune, along with the appropriate low and high injector slope values for the injectors you have selected (there are other changes as well, but those are the biggies).
Calibrated MAFs are a kludge, left over from the days when you couldn't reprogram an ECU. They work by lying to the the ECU about how much air is being ingested, tricking it into working with larger capacity injectors by telling it that less air is coming in than really is.
The quickest way to make a EEC-V or newer engine nearly un-tunable is to use a "calibrated" MAF with an unknown transfer function...
-----------------------------------------
FWIW--Here's a comparison of some MAF transfer function I did last month:
The 90mm Lightening MAF pegs at 3500 lb/h or so, which using the above assumptions would be 530 flywheel HP running n/a.
Of further nterest might be that the EEC-V core will only recognise air flows to 1700 kg/h (3750 lb/h--570 fwHP or so), beyond that scaling of the MAF/injector/displacement values is needed to tune the stock PCM.
At 12.5:1 AFR (a good place to be for n/a) that 2700 lb/h of air will need 216 lb/h of fuel to go with it. 216 lb/h of fuel, at 95% VE (Volumetric Efficiency), and 0.5 BSFC (Brake Specific Fuel Consumption) will support (216 / 0.5) * 0.95 = 410 HP.
Meaning that in the real world it (the OEM 80mm MAF) is solidly good to 390 to 400 flywheel HP--340 or so at the wheels.
Please keep in mind that these are "rule of thumb" type formulas good for establishing starting points, not absolute real world performance calculations...
Also, to reinforce what others have said, on EEC-V ("eek-5") and newer systems you do not need, nor should you seek out, a so-called "calibrated" MAF. You just buy a MAF and program that MAFs transfer function in to your tune, along with the appropriate low and high injector slope values for the injectors you have selected (there are other changes as well, but those are the biggies).
Calibrated MAFs are a kludge, left over from the days when you couldn't reprogram an ECU. They work by lying to the the ECU about how much air is being ingested, tricking it into working with larger capacity injectors by telling it that less air is coming in than really is.
The quickest way to make a EEC-V or newer engine nearly un-tunable is to use a "calibrated" MAF with an unknown transfer function...
-----------------------------------------
FWIW--Here's a comparison of some MAF transfer function I did last month:
The 90mm Lightening MAF pegs at 3500 lb/h or so, which using the above assumptions would be 530 flywheel HP running n/a.
Of further nterest might be that the EEC-V core will only recognise air flows to 1700 kg/h (3750 lb/h--570 fwHP or so), beyond that scaling of the MAF/injector/displacement values is needed to tune the stock PCM.
Last edited by cliffyk; 02-07-2010 at 07:40 AM.
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