Couple of questions...
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Joined: Aug 2002
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From: Gainesville, FL
Car: 1988 Chevy Camaro Hardtop
Engine: Turbocharged/Intercooled 3.1
Transmission: World Class T5 5 Speed
Couple of questions...
Am I correct in the following?
The 2.8 V6 MAF is a frequency film based AC Rochestor built mass air flow device.
The TPI MAFs are all Bosch Hot Wire based MAFs.
Hot wire maf = output in voltage, from 0-5v
Hot film (frequency) maf = output in Hz, from 32-150hz.
Now, if I'm correct in the above, then the '302 ecu in my '88 2.8 Camaro reads a certain Hz as a certain mass of air.
What's the highest fq the V6 MAF will read?
The 2.8 V6 MAF is a frequency film based AC Rochestor built mass air flow device.
The TPI MAFs are all Bosch Hot Wire based MAFs.
Hot wire maf = output in voltage, from 0-5v
Hot film (frequency) maf = output in Hz, from 32-150hz.
Now, if I'm correct in the above, then the '302 ecu in my '88 2.8 Camaro reads a certain Hz as a certain mass of air.
What's the highest fq the V6 MAF will read?
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Joined: Jul 2000
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Engine: 5.7L V8
Transmission: 700R4
According to http://retro.co.za/efi/DIY_EFI/1996/efi1-195.txt:
But that doesn't help you because it doesn't give the corresponding airflow values.
Here's one for an LT1 MAF:
From: John Dammeyer <johnd@xxx.com>
Date: Wed, 10 Jul 96 23:33 PDT
Subject: Re: GM Mass Airflow Sensor
At 05:02 PM 10/07/1996 -0500, you wrote:
>RABBITT_Andrew@xxx.au wrote:
>>
>> >>>I'm curious if anybody has a clue as to the upper (frequency
>> output) limit of the currently used GM mass-airflow sensor.<<<
>>
>> does 9600 Hz make any sense?
>
>the GM manual I have has the freq listed as 30HZ-150HZ unless that has
>changed, last 1 I checked was out of an 1982 Firebird and that was
>right.
Date: Wed, 10 Jul 96 23:33 PDT
Subject: Re: GM Mass Airflow Sensor
At 05:02 PM 10/07/1996 -0500, you wrote:
>RABBITT_Andrew@xxx.au wrote:
>>
>> >>>I'm curious if anybody has a clue as to the upper (frequency
>> output) limit of the currently used GM mass-airflow sensor.<<<
>>
>> does 9600 Hz make any sense?
>
>the GM manual I have has the freq listed as 30HZ-150HZ unless that has
>changed, last 1 I checked was out of an 1982 Firebird and that was
>right.
Here's one for an LT1 MAF:
From: john spears <speartec@xxx.net>
Date: Thu, 11 Jul 96 18:54 EST
Subject: RE: GM mass airflow sensor
I've seen several questions/comments about the output of GM MAF sensors. I
ran an airflow vs. frequency output today on the LT1 MAF that is used on the
high output aluminum head version (F and Y car) and also on the LT4 (Y car).
This is the largest diameter MAF sensor (3.5" O.D.) used on GM engines I
beleive, so it would support the most HP. The flow is in grams/second and
the output is in kilohertz.
5gm/sec = 2 khz (idle)
50gm/sec = 5.0khz
100gm/sec = 6.7khz
150gm/sec = 7.7khz
200gm/sec = 8.5khz
250gm/sec = 9.2khz
300gm/sec = 9.7khz
335gm/sec = 10 khz (max)
I hope that's of some value.
Date: Thu, 11 Jul 96 18:54 EST
Subject: RE: GM mass airflow sensor
I've seen several questions/comments about the output of GM MAF sensors. I
ran an airflow vs. frequency output today on the LT1 MAF that is used on the
high output aluminum head version (F and Y car) and also on the LT4 (Y car).
This is the largest diameter MAF sensor (3.5" O.D.) used on GM engines I
beleive, so it would support the most HP. The flow is in grams/second and
the output is in kilohertz.
5gm/sec = 2 khz (idle)
50gm/sec = 5.0khz
100gm/sec = 6.7khz
150gm/sec = 7.7khz
200gm/sec = 8.5khz
250gm/sec = 9.2khz
300gm/sec = 9.7khz
335gm/sec = 10 khz (max)
I hope that's of some value.
Thread Starter
Supreme Member
Joined: Aug 2002
Posts: 3,827
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From: Gainesville, FL
Car: 1988 Chevy Camaro Hardtop
Engine: Turbocharged/Intercooled 3.1
Transmission: World Class T5 5 Speed
LT1 MAF = 2-10kHz? ok, cool... now to find out how the computer reads the frequency...
For example -
V6 MAF =
32hz-150hz
Now, has anyone actually found a graph to determine how high the 2.8 MAF will read, in Hz?
Also, is the output directly in Hz to the ECM?
For example -
V6 MAF =
32hz-150hz
Now, has anyone actually found a graph to determine how high the 2.8 MAF will read, in Hz?
Also, is the output directly in Hz to the ECM?
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From: Moorestown, NJ
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
Dont know much about MAF but the highest youll be able to read will be 255 grams/sec of airflow due to the fact that the computer is 8 bit. I could see that limit being hit with a turbo.
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From: great lakes
the real issue of the MAF itself is that the stock 2.8 v6 maf is calibrated for 150 grs/sec of air flow. how ever a GN maf has the same output 32-150 hz but is calibrated for 255 grs/sec. the maf tables in teh ECM will have to be redone to accomadate for this and the scalars will have to be modified as well. but youll gain a good bit of overhead. the maf itself will not read more then 150 grs/sec.
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