|
Title: Larger MAF housing: what factor (if any) to use to get accurate sensor reading Post by: vtraudt on September 07, 2013, 04:26:45 PM Installed a larger MAF housing, same sensor (Giac PC16 tune).
Can the MAF values in g/sec be corrected by the square of the area ration (bigMAFarea/smallMAFarea)? Example: reading 190 g/sec Diameter ratio: 76/60=1.27 Area ratio: 1.27x1.27=1.60 actual MAF: 190x1.60=305 g/sec Title: Re: Larger MAF housing: what factor (if any) to use to get accurate sensor reading Post by: julex on October 04, 2013, 07:45:46 AM Installed a larger MAF housing, same sensor (Giac PC16 tune). Can the MAF values in g/sec be corrected by the square of the area ration (bigMAFarea/smallMAFarea)? Example: reading 190 g/sec Diameter ratio: 76/60=1.27 Area ratio: 1.27x1.27=1.60 actual MAF: 190x1.60=305 g/sec That's how you adjust the maf tables, area multiplier. Title: Re: Larger MAF housing: what factor (if any) to use to get accurate sensor reading Post by: julex on October 17, 2013, 10:39:59 AM Installed a larger MAF housing, same sensor (Giac PC16 tune). Can the MAF values in g/sec be corrected by the square of the area ration (bigMAFarea/smallMAFarea)? Example: reading 190 g/sec Diameter ratio: 76/60=1.27 Area ratio: 1.27x1.27=1.60 actual MAF: 190x1.60=305 g/sec Yup, you multiply all values by 1.60 and you're done. Title: Re: Larger MAF housing: what factor (if any) to use to get accurate sensor reading Post by: ddillenger on October 17, 2013, 10:46:59 AM Ever scale a bosch sensor?
:) First 101 values are negative flow. Increase those and..... Well, it's not great. Title: Re: Larger MAF housing: what factor (if any) to use to get accurate sensor reading Post by: nyet on October 17, 2013, 11:47:03 AM Ever scale a bosch sensor? :) First 101 values are negative flow. Increase those and..... Well, it's not great. yep. just requires a bit of math... need to scale the MAF offset and scale AND shift the MAF curve accordingly... got me thinking since your last email to me. i have a hacked together spreadsheet that does this but i haven't quite got it right yet. the trick with bosch is to dont do any scaling until you've taken the offset into account. subtract the offset, create the "stock" transfer function. Then scale that. then move the offset back for the zero point.. done.. Title: Re: Larger MAF housing: what factor (if any) to use to get accurate sensor reading Post by: leolux on November 29, 2013, 07:47:34 AM Installed a larger MAF housing, same sensor (Giac PC16 tune). Can the MAF values in g/sec be corrected by the square of the area ration (bigMAFarea/smallMAFarea)? Example: reading 190 g/sec Diameter ratio: 76/60=1.27 Area ratio: 1.27x1.27=1.60 actual MAF: 190x1.60=305 g/sec Hi, if you have an old HFM from Bosch like your 1.8t AEB or an old VR6 8(Bit ECU) you can do it like your area calcluation (perhaps so more easy (newdia/olddia)²=area ratio. If you want to do it more corectly you must be calclutate the area who the sensor gets in the old Case in percent and the areas in new case in parcent. Because the sensor areas is the same and in the areas factor of you calcuation you are rise it with the diameter and that is not so.... on the 16bit (HFM5) is the best you put your values in g/S from kg/h than you can do the same thing like in top... Dont forget to rescale your load signal thats importent in the old motronic, because the injector size is binded with load. I have last time started to tune my audi tt in ME 7.5 its not compareable with the old Motronic (3.8X). My car run about 450 HP with only one flash, and i have change much components (RS4 HFM, 1000cc BOSCH, tail 38mm, with pt5858) Leo Title: Re: Larger MAF housing: what factor (if any) to use to get accurate sensor reading Post by: eliotroyano on November 29, 2013, 01:09:18 PM Nice comment but just to check it, M38x & M592 ECUs are 16bit too.
Title: Re: Larger MAF housing: what factor (if any) to use to get accurate sensor reading Post by: leolux on December 01, 2013, 05:28:51 PM Nice comment but just to check it, M38x & M592 ECUs are 16bit too. Sorry for missunderstod, of corse i have call the ECUs 8Bit, because the most of maps are in 8 bit defined, but that ar enot correct. The CPU operates in 16BIt mode... :)Title: Re: Larger MAF housing: what factor (if any) to use to get accurate sensor reading Post by: hammersword on December 01, 2013, 05:39:22 PM increasing the correct map by x% or X value will mess the things up. MLHFM is the answer
Title: Re: Larger MAF housing: what factor (if any) to use to get accurate sensor reading Post by: ddillenger on December 01, 2013, 06:07:00 PM increasing the correct map by x% or X value will mess the things up. MLHFM is the answer Fotis: Can you elaborate? I've read that just transplanting the MLHFM from the correct sensor rarely works, that a lot more is needed. Is this not the case? Title: Re: Larger MAF housing: what factor (if any) to use to get accurate sensor reading Post by: leolux on December 10, 2013, 04:32:19 AM Fotis: Can you elaborate? I've read that just transplanting the MLHFM from the correct sensor rarely works, that a lot more is needed. Is this not the case? In my experienc i can say it works... At best you can test it if you change only the MAF and values and not other like injectors. The most problem ist the most changes all together and then its verry dificult to found the fault (KRKTE, MINTE, TVUB and other need maps) if its running not perfect.... I have the best results if i work bottum up and do my best to get the stock drivebility after change the components and values one by one. In the ME7.5 you can compare the KFKHFM too on some cars the corect the bad intake linarity with them. If you have an good intake you can set them on 1 like the rs4 have it stock (1.0235)... sorry4myenglish Leo |