How do U modify stock MAF ?
12-10-2006, 08:03 AM
#11
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RE: How do U modify stock MAF ?
Poobs, if all you have is a non-PI pulley/catback/mid-pipe GT you should leave your MAF alone. It's far too risky to fool around with it, especially without getting it on a dyno before you take the first trip down the road.
You should be far more concerned about a PI swap or forced induction than looking for ways to 'tweak' your MAF. It'll never net you gains worth the research/labor/risk involved, ever.
You should be far more concerned about a PI swap or forced induction than looking for ways to 'tweak' your MAF. It'll never net you gains worth the research/labor/risk involved, ever.
12-10-2006, 01:17 PM
#12
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RE: How do U modify stock MAF ?
Dan
Thank you much for the advice. You are correct. This is purely tweaking for fun and hopefully too learn a thing or two.
As I meantioned earlier, I have a CL MAF that seems to be doing a great job plus a spare MAF that I can bolt back on if there are any doubts about the ground up MAF housing.
I was looking at the center post piece that I cut out of the stock MAF and there was another way that I could have gone - I could have also ground down the thickness of the center post. The original casting is quite thick
Later
Thank you much for the advice. You are correct. This is purely tweaking for fun and hopefully too learn a thing or two.
As I meantioned earlier, I have a CL MAF that seems to be doing a great job plus a spare MAF that I can bolt back on if there are any doubts about the ground up MAF housing.
I was looking at the center post piece that I cut out of the stock MAF and there was another way that I could have gone - I could have also ground down the thickness of the center post. The original casting is quite thick
Later
12-10-2006, 06:37 PM
#13
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RE: How do U modify stock MAF ?
Well, I installed the hacked up MAF housing and the car runs fine.
I did not pull the battery wire to re set the computer nor drive long enough to get a CEL
The car feels much like it did last time I put the stock MAF back on. The torque peak seems lower in the RPM range and it may have lost a bit of power on top end.
There is no pinging that I can detect.
My volt reading on the C&L MAF at idle were 14.28 between terminals A-B and .89 between C-D The modified unit reads 13.69 and .80 respectively
Haven't found if the above is good or bad however[:-]
I did not pull the battery wire to re set the computer nor drive long enough to get a CEL
The car feels much like it did last time I put the stock MAF back on. The torque peak seems lower in the RPM range and it may have lost a bit of power on top end.
There is no pinging that I can detect.
My volt reading on the C&L MAF at idle were 14.28 between terminals A-B and .89 between C-D The modified unit reads 13.69 and .80 respectively
Haven't found if the above is good or bad however[:-]
12-12-2006, 11:20 AM
#15
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RE: How do U modify stock MAF ?
I have a volt meter, oscilloscope........ Unfortunately I do not have anything accurate to measure fuel mixture etc.
What I have been using is my nose to smell unburnt fuel at idle.
Seat of the pants, gas mileage and the eventual change in color of the spark plugs
12-17-2006, 12:01 AM
#16
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RE: How do U modify stock MAF ?
Done quite a bit of driving since my last post on this topic - no CEL or adverse effects yet
.
Today I was throwing the car around a bit - It feels virtually the same as with the C&L 80mm MAF. It may even be a bit more responsive to the gas pedal on the bottom end, when you get on it however the top end is not the same as with the C&L.
Driving the car now reminds me of a car with a smaller carburetor or driving with a carb that has real small primaries.
I'm thinking of wiring in a cheap air fuel gage. I know it will not be the same as a calibarted wide band gage but it will tell the realtive diferences between the C&L , stock and modified stock MAF
.Today I was throwing the car around a bit - It feels virtually the same as with the C&L 80mm MAF. It may even be a bit more responsive to the gas pedal on the bottom end, when you get on it however the top end is not the same as with the C&L.
Driving the car now reminds me of a car with a smaller carburetor or driving with a carb that has real small primaries.
I'm thinking of wiring in a cheap air fuel gage. I know it will not be the same as a calibarted wide band gage but it will tell the realtive diferences between the C&L , stock and modified stock MAF
12-17-2006, 04:02 PM
#17
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RE: How do U modify stock MAF ?
Get it on a dyno and see if it's made any differences. I'd be shocked if it did, but it'd be worthwhile information to someone else since it is essentially a free mod.
Dyno dyno dyno
Dyno dyno dyno
12-20-2006, 04:27 AM
#19
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RE: How do U modify stock MAF ?
Don't hose around with your MAF, it isn't worth it.
Go to C&L and find out what the CORRECT sample tube is, and use it.
http://www.cnlperformance.com/calibration.html
Either that or go back to the stock assembly (if it is still intact).
(C&L does not publish their sample tube diameters, but I have most of them listed on my site. Sometimes the sample tubes lose their color, or are mis-colored)
Truth is, you have no idea how the car is running as you can't monitor AFR or the KAMRF's with a voltmeter or scope.
Until you have checked both the KAMRF's and AFR, you can't say if the engine is running properly or not.
The 'Nose' test is obviously lame.
Using a voltmeter to measure the output of the MAF/MAS will tell you basically nothing. You also have to know how the computer will interpret that voltage.
The MAF/MAS uses a conversion factor to convert airflow to voltage. (not really how it works, but it makes the point)
Once the computer has the voltage... the computer uses a conversion factor to turn that voltage back into an airflow number.
By modifying the internals of the MAF tube, you changed the conversion factor that the MAF/MAS uses.
The bad part is that the computer doesn't know that things have changed.
With your mods, there is no reason to mess with the MAF/MAS.
There are better things to spend your time/money on.
sorry it's so random,
hope it helps
jason
Go to C&L and find out what the CORRECT sample tube is, and use it.
http://www.cnlperformance.com/calibration.html
Either that or go back to the stock assembly (if it is still intact).
(C&L does not publish their sample tube diameters, but I have most of them listed on my site. Sometimes the sample tubes lose their color, or are mis-colored)
Truth is, you have no idea how the car is running as you can't monitor AFR or the KAMRF's with a voltmeter or scope.
Until you have checked both the KAMRF's and AFR, you can't say if the engine is running properly or not.
The 'Nose' test is obviously lame.
Using a voltmeter to measure the output of the MAF/MAS will tell you basically nothing. You also have to know how the computer will interpret that voltage.
The MAF/MAS uses a conversion factor to convert airflow to voltage. (not really how it works, but it makes the point)
Once the computer has the voltage... the computer uses a conversion factor to turn that voltage back into an airflow number.
By modifying the internals of the MAF tube, you changed the conversion factor that the MAF/MAS uses.
The bad part is that the computer doesn't know that things have changed.
With your mods, there is no reason to mess with the MAF/MAS.
There are better things to spend your time/money on.
sorry it's so random,
hope it helps
jason
12-20-2006, 10:05 AM
#20
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RE: How do U modify stock MAF ?
Thanks Jason. I apreciate the advice and I agree with you.
Actually the C&L has what should be the correct tube for my motor mods etc.I also tried two other tubes and both of these triggered CEL. The codes were something to do with lean bank or something to that effect.
Actually the C&L has what should be the correct tube for my motor mods etc.I also tried two other tubes and both of these triggered CEL. The codes were something to do with lean bank or something to that effect.