NefMoto

Technical => Tuning => Topic started by: lulu2003 on April 27, 2012, 03:30:33 AM



Title: extend the limits of stock MAF/HFM
Post by: lulu2003 on April 27, 2012, 03:30:33 AM
I cannot find anything with search or google.
shouldn't it be possible by a higher heating voltage or current to extend the max. range of the sensor (and then calibrate MLHFM etc.)

I don't think it's quite easy to find a plug&play replacement for a Bosch HFM5 which goes beyond 500g/s or 1700-1800 kg/h (increase of around 20-25%).




Title: Re: extend the limits of stock MAF/HFM
Post by: cactusgreens4 on April 27, 2012, 01:52:03 PM
As far as I know the only way to extend the range of the sensor is to put it in a bigger housing... i.e. 83 85 or 90 mm intake pipe.


Title: Re: extend the limits of stock MAF/HFM
Post by: lulu2003 on April 28, 2012, 12:26:01 AM
yes, the housing would be also a way to go, but first you need a housing that fits the MAF and I am not sure how this behaves when the diameter of the pipes before and after that new howsing remains small...


Title: Re: extend the limits of stock MAF/HFM
Post by: nyet on April 29, 2012, 05:44:30 PM
You don't have a choice. The purpose of using a larger housing is because at some air velocity (at a given temp/pressure/humidity), the MAF outputs its maximum voltage.

Please reread the s4wiki MAF article.


Title: Re: extend the limits of stock MAF/HFM
Post by: lulu2003 on April 30, 2012, 01:46:38 AM
I am 100% aware of the function and Output of the MAF, that's why I am asking.
at least in theory it should be possible to tweak the sensor itself to extend measuring range as I stated in the starting post.


Title: Re: extend the limits of stock MAF/HFM
Post by: matchew on April 30, 2012, 02:59:24 AM
Yes. There are specialist company's out there that do this with MAF's from other marques.


Title: Re: extend the limits of stock MAF/HFM
Post by: nyet on April 30, 2012, 09:00:04 AM
I am 100% aware of the function and Output of the MAF, that's why I am asking.
at least in theory it should be possible to tweak the sensor itself to extend measuring range as I stated in the starting post.

Ah. Sorry, I misunderstood your post.


Title: Re: extend the limits of stock MAF/HFM
Post by: lulu2003 on April 30, 2012, 10:56:03 AM
nyet: no problem.


As far as I know the only way to extend the range of the sensor is to put it in a bigger housing... i.e. 83 85 or 90 mm intake pipe.

I guess these housings are usually very custom. I saw some build with CNC'ed aluminium. I'd prefer a OEM black plastic one that fits the ord sensor and has 100mm inner diameter.

Quote
Yes. There are specialist company's out there that do this with MAF's from other marques.

any ideas what they did? any name or link?


Title: Re: extend the limits of stock MAF/HFM
Post by: lulu2003 on May 02, 2012, 05:50:31 AM
what about the rs4 maf. it's "only" around 83mm and has maximum of 2000kg/h (556g/s) at 5V in MLHFM. how comes?