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NB-V70R

The Black Magic Wagon - A 1998 V70R Build Tale

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3 hours ago, NB-V70R said:

Also still have to play around with the MAF constant. Has anyone who performed a significant MAF upgrade have to change any other parameters besides the MAF map to achieve prior drivability? The more I play around with the MAF scaling, the more it seems like other things need to be modified as well such as acceleration enrichment and so on. Thanks for any insight!

What size MAF housing are you using?  The original MAF editor just multiplies the constants in your bin maf table by whatever multiplier constant you enter.  I.e. the usual constants supplied (1.34, 1.94, 2.57) assume you're starting with a stock bin.

If you've already modified the MAF table in your bin and you need to update it again (and you're going with one of the std sizes) I recommend you use the "Alternative Mafconverter" available here:

http://m44.wikia.com/wiki/Modified_Vehicles

direct link:

http://www.meditekst.nl/M44/M44_MAF_Converter.zip

 

I recently ran into this when I switched from S90 to 540i maf housing.  To answer your question; no, if the maf conversion is done correctly, you should not have to mod other params for the maf update.

And remember, use your stock maf sensor; you're only up-sizing the housing.

BTW: I'm assuming we can all thank Piet for both of these apps?  :biggrin:

Edited by gdog

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the two o-rings/seals on the maf are also very important...

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On 5/10/2018 at 11:16 PM, gdog said:

What size MAF housing are you using?  The original MAF editor just multiplies the constants in your bin maf table by whatever multiplier constant you enter.  I.e. the usual constants supplied (1.34, 1.94, 2.57) assume you're starting with a stock bin.

If you've already modified the MAF table in your bin and you need to update it again (and you're going with one of the std sizes) I recommend you use the "Alternative Mafconverter" available here:

http://m44.wikia.com/wiki/Modified_Vehicles

direct link:

http://www.meditekst.nl/M44/M44_MAF_Converter.zip

 

I recently ran into this when I switched from S90 to 540i maf housing.  To answer your question; no, if the maf conversion is done correctly, you should not have to mod other params for the maf update.

And remember, use your stock maf sensor; you're only up-sizing the housing.

BTW: I'm assuming we can all thank Piet for both of these apps?  :biggrin:

Thanks for the response,

I'm using a 3.5in OD MAF housing (which I think measured 3.25" ID) with my stock sensor of course. I started with 1.94 as my multiplier in that tool you linked, but I remember the car running rich mostly, but swinging to lean with the fuel trims occasionally. This was all before I bent those rods a couple months ago and I wasn't datalogging at the time. Since then, I've tried multiplying that (x1.94) table by 0.9 (which seemed too lean), 0.95,  and 0.96 which I have been running on for a couple of weeks. My idle fuel trims are not any more than they were before the upgrade. AFR at WOT was 11.7 or so before the upgrade and now dips into the high 9s. My bin is pretty far from stock though with modified injectors, load axes rescaled and so on. If those other things were done incorrectly I could see that flaring up and causing a problem.

The more I write about it, it kind of sounds like I have a boost leak. I'm gonna go check my charge piping after this.

 

On 5/11/2018 at 8:45 AM, gmsgltr said:

the two o-rings/seals on the maf are also very important...

I don't remember removing or keeping them lol.... I'll have to pop out the sensor to double check.

OK nvm it is 95 deg out so I'll check it later :blink:

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Car looks great so far! mad props. 

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Trying to prevent the archive :blockhead:. I'm deep into my last year of engineering school and I'm looking forward to graduation in May so I can get back to all my plans on this car. I haven not been able to track down the running issue. I was able to minimize the problematic behavior with a bit of tuning, but it still gets me everywhere I need to go reliably so it isn't top priority.

It doesn't help that I keep spending money on computer upgrades, the racecar, and my new Motorcycle (2013 Honda CB500F) lol.

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