MAFs
20 January 2007, 08:28 AM
#6
Scooby Regular
Do you have an Apexi Power FC....?
If so the perfect upgrade for you would be to fit the Version 4 Sti maf...
Needs a bit of rewiring on either the plug or inside the maf is our preferred method...
If not , why are you trying....?
If so the perfect upgrade for you would be to fit the Version 4 Sti maf...
Needs a bit of rewiring on either the plug or inside the maf is our preferred method...
If not , why are you trying....?
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20 January 2007, 05:12 PM
#9
Scooby Regular
As stated above none unless you wish to make a specific power output...I have found that the standard 93-96 mafs run out of voltage at about 1.2 bar boost on a TD05 , or roughly 320hp...
The version 4 maf will flow well beyond 400hp and I have carried out this conversion on a number of cars recently...Works very well....
The version 4 maf will flow well beyond 400hp and I have carried out this conversion on a number of cars recently...Works very well....
20 January 2007, 06:22 PM
#10
Scooby Regular
a MAF measures the Air Flow ...... why the hell would anyone want to change it/
and to whoever said the standard one runs out of voltage .... WTF??
You are a bunch of wallys!!
and to whoever said the standard one runs out of voltage .... WTF??
You are a bunch of wallys!!
20 January 2007, 07:01 PM
#11
[quote=pslewis;6569999]a MAF measures the Air Flow ...... why the hell would anyone want to change it/ only need to change it if the airflow exceeds the measuring specifications of the oe maf, when uprating the power of the car.
and to whoever said the standard one runs out of voltage .... WTF??
The maf converts airflow into voltage. The maf output voltage is usually between 1 volt and 5 volts, 5 volts being maximum airflow for that particular maf at a certain airlfow. To get more power you need to increase the airflow. If the power increase/airflow is beyond the measuring capabilities of the oe maf, then an uprated maf will be needed to measure the airflow to ensure correct air to fuel ratio is maintained
/quote]
I thought you came from an engineering background Mr lewis
and to whoever said the standard one runs out of voltage .... WTF??
The maf converts airflow into voltage. The maf output voltage is usually between 1 volt and 5 volts, 5 volts being maximum airflow for that particular maf at a certain airlfow. To get more power you need to increase the airflow. If the power increase/airflow is beyond the measuring capabilities of the oe maf, then an uprated maf will be needed to measure the airflow to ensure correct air to fuel ratio is maintained
/quote]
I thought you came from an engineering background Mr lewis
20 January 2007, 07:06 PM
#12
Scooby Regular
I understand the principles .... its the thought of running out of voltage that makes me chuckle
The resistance changes and it varies the output voltage to the ECU ..... it doesn't run out of voltage.
Does the ECU actually 'see' anything over 5volts? If that is the maximum it can register it would flag a fault if it became 8volts, say.
All the ECU needs to know is what air flow 5volts indicates ... no need to change the MAF just the ECUs understanding of the voltage it receives!
The resistance changes and it varies the output voltage to the ECU ..... it doesn't run out of voltage.
Does the ECU actually 'see' anything over 5volts? If that is the maximum it can register it would flag a fault if it became 8volts, say.
All the ECU needs to know is what air flow 5volts indicates ... no need to change the MAF just the ECUs understanding of the voltage it receives!
20 January 2007, 07:13 PM
#13
I understand the principles .... its the thought of running out of voltage that makes me chuckle Who mentioned running out of voltage
The resistance changes and it varies the output voltage to the ECU ..... it doesn't run out of voltage. see above
Does the ECU actually 'see' anything over 5volts? If that is the maximum it can register it would flag a fault if it became 8volts, say. the ecu most likely runs on a 5 volt supply and all pull up/down circuits will be limited to 5 volts max
All the ECU needs to know is what air flow 5volts indicates ... no need to change the MAF just the ECUs understanding of the voltage it receives! but different mafs give different readings for a specific airflow, hence if you want to increase power over a certain level the oe maf is not able to translate the increase into a variable voltage
The resistance changes and it varies the output voltage to the ECU ..... it doesn't run out of voltage. see above
Does the ECU actually 'see' anything over 5volts? If that is the maximum it can register it would flag a fault if it became 8volts, say. the ecu most likely runs on a 5 volt supply and all pull up/down circuits will be limited to 5 volts max
All the ECU needs to know is what air flow 5volts indicates ... no need to change the MAF just the ECUs understanding of the voltage it receives! but different mafs give different readings for a specific airflow, hence if you want to increase power over a certain level the oe maf is not able to translate the increase into a variable voltage
20 January 2007, 07:27 PM
#15
Your pedantic nature, but basically is correct in that once the airflow exceeds measuring capabilties of the oe maf, then yes it runs out of voltage, (peaks at 5volts )and doesnt indicate any further airflow above that threshold.
I find it unusual that you pick up certain phrases that arent lets say technically correct, but yet you play the ignoramus when it comes to the use and function of the knocklink
I find it unusual that you pick up certain phrases that arent lets say technically correct, but yet you play the ignoramus when it comes to the use and function of the knocklink
20 January 2007, 09:09 PM
#16
Scooby Regular
I could knock one up on my kitchen table for £5 ..... but, it may as well be a random light generator for all the REAL use it does!
It tells you that there is some noise, somewhere in the engine compartment, so bloody what??
It converts that noise (which could be a loose exhaust manifold) into a RED light and sends the fear of god up the non-technical driver!!
20 January 2007, 09:42 PM
#17
Scooby Regular
Starting on me now are you..... 
lol
I know that it doesn't get to 5.11 volts and then blow up....
What I am saying is that if you exceed the range of the airflow meter it can't tell the ecu when more fuel is reqd...I have seen the effects of this on the rollers and prefer to fit a larger maf or larger maf tube to overcome this...Gives you a margin of safety should you get a boost spike etc...
This isn't an expensive option...Subaru main dealers can supply the V4 STi mafs for £189 new...Even cheaper than fitting a new standard one....
P.S I tune cars for a living , what do you do.....!
lolI know that it doesn't get to 5.11 volts and then blow up....
What I am saying is that if you exceed the range of the airflow meter it can't tell the ecu when more fuel is reqd...I have seen the effects of this on the rollers and prefer to fit a larger maf or larger maf tube to overcome this...Gives you a margin of safety should you get a boost spike etc...
This isn't an expensive option...Subaru main dealers can supply the V4 STi mafs for £189 new...Even cheaper than fitting a new standard one....
P.S I tune cars for a living , what do you do.....!
Last edited by MartynJ; 20 January 2007 at 09:47 PM.
20 January 2007, 10:09 PM
#18
Scooby Regular
I only design Nuclear Warheads and Missile Guidance Systems ..... nothing compared to messing about with cars, granted - but, its a job 
And I was asked where I had read the words .... I was merely answering a question - I would NEVER go up against a car tuner when talking Engineering Design 
And I was asked where I had read the words .... I was merely answering a question - I would NEVER go up against a car tuner when talking Engineering Design
20 January 2007, 11:07 PM
#20
Scooby Regular
30 years in the game...Longer than most...
Can't say anymore i'm afraid due to SNets strict advertising policy...
Can't say anymore i'm afraid due to SNets strict advertising policy...
21 January 2007, 12:06 AM
#21
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reason i ask was ithink my MAf is on way out car gets a bit juddery and since i have to replace it i thought might be worth upgradeing. I am going to be getting car mapped to about 320 340 bhp so thought it may be worth while
21 January 2007, 09:23 AM
#22
Scooby Regular
As I mentioned the larger maf is actually cheaper than replacing the standard one so seems the best course of action to me....
Part number should you require it 22680AA270
Part number should you require it 22680AA270
21 January 2007, 10:53 AM
#24
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On the contrary, I understand FULLY what a cockLink is doing ..... it is simply turning a Knock Sensor Output into an LED readout. The louder the knock, the higher the voltage and the more LEDs are illuminated.
I could knock one up on my kitchen table for £5 ..... but, it may as well be a random light generator for all the REAL use it does!
It tells you that there is some noise, somewhere in the engine compartment, so bloody what?? It converts that noise (which could be a loose exhaust manifold) into a RED light and sends the fear of god up the non-technical driver!!
I could knock one up on my kitchen table for £5 ..... but, it may as well be a random light generator for all the REAL use it does!
It tells you that there is some noise, somewhere in the engine compartment, so bloody what??
It converts that noise (which could be a loose exhaust manifold) into a RED light and sends the fear of god up the non-technical driver!!
21 January 2007, 10:53 AM
#25
Scooby Regular
If your MAF needs replacing, it's often thought that an upgrade might be in order, seeing as MAFs are so expensive anyway. As mentioned above, your MAF is maxing out if the ECU starts to read above 5v roughly.
I wouldn't recommend changing your MAF for any different model unless you're remapping as well e.g. with a Power FC, in which case you can use any MAF which will physically fit because the MAF output can be rescaled so 5v will indicate a higher airflow than 5v would have done previously in your old MAF.
I'm no nuclear weapon designer or car tuner of 30 years, but I understand electronics and cars, and I am in roughly the same position as you. I personally will be fitting a Nissan Z32 MAF to replace my v4 UK MAF and will be getting it remapped at the same time.
I wouldn't recommend changing your MAF for any different model unless you're remapping as well e.g. with a Power FC, in which case you can use any MAF which will physically fit because the MAF output can be rescaled so 5v will indicate a higher airflow than 5v would have done previously in your old MAF.
I'm no nuclear weapon designer or car tuner of 30 years, but I understand electronics and cars, and I am in roughly the same position as you. I personally will be fitting a Nissan Z32 MAF to replace my v4 UK MAF and will be getting it remapped at the same time.
21 January 2007, 11:29 AM
#26
Scooby Regular
Larger than both the Z32 maf and the standard uk maf...
Hence why it has also been suggested that you could remove the maf from its original body and place it in a larger tube...Much the same effect but why bother when Subaru have already done it for you...
Depending on the version of Apexi Power Fc the airflow table has also already been calculated and is selected in the airflow map by selecting the 90mm setting...
As mentioned you have to have it remapped at the time of fitting...
21 January 2007, 12:56 PM
#27
Scooby Regular
Excellent thread 
I was under the impression that the 'upgraded' MAF would be placed in the same induction volume space. Thats not the case and also a re-map is mentioned to tell the ECU what is in the Induction side.
You are a bunch of clever lads ....
BUT, in my opinion, the CockLink is meaningless - I have never, even in the slightest, been convinced otherwise.
I was under the impression that the 'upgraded' MAF would be placed in the same induction volume space. Thats not the case and also a re-map is mentioned to tell the ECU what is in the Induction side.
You are a bunch of clever lads ....
BUT, in my opinion, the CockLink is meaningless - I have never, even in the slightest, been convinced otherwise.
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