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Old 21st May 2017, 13:00   #21
Richard1973
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Am I right in thinking a 160 remap does away with the need for a MAF?
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Old 21st May 2017, 13:11   #22
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Am I right in thinking a 160 remap does away with the need for a MAF?


No, afraid not.


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Old 21st May 2017, 18:09   #23
Mike Noc
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Am I right in thinking a 160 remap does away with the need for a MAF?

IIRC Dakta offers a MAFless remap over on the Dark Side.
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Old 24th May 2017, 00:47   #24
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The reason the OE MAF sensor is considerably more expensive than the aftermarket ones is a simple one.

The original unit uses a platinum hot film anemometer, i.e. it is a constant temperature thermistor arranged in a wheatstone bridge.


So this is how it works


Power from the ECM heats the thermistor up to a predetermined temperature TH. A airflow with velocity V and ambient temperature TA cools the heater down until an equilibrium between the electrical heat and the thermal heat loss Q is reached.

The higher the velocity V and the difference TH-A=TH-TA between the thermistor temperature TH and the variable inlet air temperature TA, the higher is the heat loss from the platinum hot film thermistor.

The inlet air temperature TA, which can change, so TH-A is measured with an additional inlet air temperature sensor which is part of the bridge circuit in order to compensate changes in the ambient temperature automatically.

Basically this speed, volume and temperature of the incoming air charge is calculated by the ECM based upon the heat loss of the platinum hot film thermistor, and the fuelling is adjusted accordingly

Aftermarket MAF sensors generally speaking are cheaper because of the metal composition of the heater thermistor, and quite often the inlet air temperature components are omitted, meaning the output offset voltages are misinterpreted by the ECM

This is one case where buying cheaply certainly means buying twice, and when looking at the live data, I can spot a mile off if a car is fitted with a generic MAF sensor, or indeed a Pierburg MAF sensor, which incidentally does not include any form of inlet air temperature sensor

So if your MAF sensor is definitely knackered, and yes unplugging it and seeing an improvement in performance is not a reliable method of testing, save yourself the wasted money of buying anything other than the Bosch unit.

Like Russ has said, most if not all aftermarket sensors have been trialled and found to be lacking.

Brian
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Old 24th May 2017, 10:40   #25
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Thanks Brian as they say you get what you pay for,luck of the draw if you get a good aftermarket unit.
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Old 24th May 2017, 17:26   #26
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Thanks Brian as they say you get what you pay for,luck of the draw if you get a good aftermarket unit.
No luck involved, quite simple...

Buy a none OEM item and it will be worse than useless.

Your choices are Rimmers, The MafShop for an OEM unit, or the MafShop to buy the cheaper version in a BMW air duct, which you then transfer to your 75 version of the air duct.
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Fix a poor handbrake; DIY ABS diagnostic unit; Loan of the spanner needed to change the CDT belts; free OBD diagnostics +MAF; Correct Bosch MAF cheap; DVB-T install in an ex-hi-line system; DD install with a HK amp; FBH servicing.

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Old 24th May 2017, 18:27   #27
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Sorry Harry don,t see why some should be so dismissive and so blatantly matter of fact about aftermarket products,I in know way am saying that all aftermarket products not just MAF,s are good,and by the same note OEM products are also not infallible to being sh1t, in my time i have fitted both good and band of both.
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Old 24th May 2017, 21:01   #28
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Sorry Harry don,t see why some should be so dismissive and so blatantly matter of fact about aftermarket products,I in know way am saying that all aftermarket products not just MAF,s are good,and by the same note OEM products are also not infallible to being sh1t, in my time i have fitted both good and band of both.
Well buy a cheap after market MAF and do let us know how it performs then. Lots on here have bought them and been disappointed with the results.

I put a lot of time into researching the cheapest way to replace mine, when I needed one a while back. I published the out come of the research I did on here.

The proper item is expensive to make, yet easy to produce a copy which will look as if it should work - the problem is they don't work. There have even been cheaper Bosch items with the model numbers changed, to the correct model for the 75 and lots of downright fakes about too. You need the correct part number and from a reputable source - as given above.
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Fix a poor handbrake; DIY ABS diagnostic unit; Loan of the spanner needed to change the CDT belts; free OBD diagnostics +MAF; Correct Bosch MAF cheap; DVB-T install in an ex-hi-line system; DD install with a HK amp; FBH servicing.

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Last edited by HarryM1BYT; 24th May 2017 at 21:16..
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Old 24th May 2017, 21:11   #29
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Have i actually said anywhere in my postings that i was going to purchase a aftermarket unit
The question was has anyone had any joy in getting one,
Yes mine is faulty has been since i bought the car it runs fine as it is so will probably leave it as it is or may even fit a second hand unit have done this in the past without any problems again pay your,e money takes your,e chances same as anything in life.
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Old 24th May 2017, 21:28   #30
HarryM1BYT
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Quote:
Originally Posted by philm View Post
Have i actually said anywhere in my postings that i was going to purchase a aftermarket unit
The question was has anyone had any joy in getting one,
Yes mine is faulty has been since i bought the car it runs fine as it is so will probably leave it as it is or may even fit a second hand unit have done this in the past without any problems again pay your,e money takes your,e chances same as anything in life.
It read as if you were asking about buying an after market item, we were ony pointing out that their are none which work properly - at all. You can easily check a MAF units output with a diagnostics unit, or at a pinch a simple multimeter. I had some small success by cleaning mine up as I recall, but they are extremely delicate units and very easy to wreck. They have a very fine platinum wire exposed in the air stream which over time can get dirty - damage that and you can bin it. The wire is finer than a human hair, invisible without a lot of magnification.
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How To's and items I offer for free, or just to cover the cost of my expenses...

http://www.the75andztclub.co.uk/foru...40#post1764540

Fix a poor handbrake; DIY ABS diagnostic unit; Loan of the spanner needed to change the CDT belts; free OBD diagnostics +MAF; Correct Bosch MAF cheap; DVB-T install in an ex-hi-line system; DD install with a HK amp; FBH servicing.

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