logging g/s with 3" maf housing

Prebs

Full Member
Dec 28, 2004
662
0
Norway, Bergen
Im about to log g/s values on my new hybrid map witch has a 3" maf housing and OE ibiza sensor.

I dont think the maf has bin re-scaled to 3" map so will I have to add 14.2% on the results to get the right values with 3" housing?

Thanks in advance
 

Prebs

Full Member
Dec 28, 2004
662
0
Norway, Bergen
Might try to move this thread to the "tuning section" to hopefully get some more feed backs.

Done several hours of searching on the web but no direct answers.
 

nev

Mar 27, 2007
618
0
Southampton
I would've thought this is incorrect to be honest. I take it from the g/s you are looking at quantity of air. The difference in size would more than likely be the change in area or volume i am not 100% on which one but can look into it. I also don't know if you can directly apply these values to a map.

In terms of area there is a 23.5% difference
 

Prebs

Full Member
Dec 28, 2004
662
0
Norway, Bergen
I would've thought this is incorrect to be honest. I take it from the g/s you are looking at quantity of air. The difference in size would more than likely be the change in area or volume i am not 100% on which one but can look into it. I also don't know if you can directly apply these values to a map.

In terms of area there is a 23.5% difference

When I was on my k03s setup I was seeing max g/s of 187 with 70mm housing.

Now Im on hybrid and coustom map (witch hasnt bin scaled for 80mm housing) so guessing the maf will under-read from more air going thro.

I was under the impression that I could take the values I get now when logging witch will be lower from more air goining throu sensor and add it all up by calculating the difference in volum between the two housings.

Why shouldnt it work? Should be a formel to use as the only variabel is bigger housing.

I might be totally off here tho:)

Havent logged it yet but will be going for a trackdsay this coming weekend and just want to know what to look for.
 

nev

Mar 27, 2007
618
0
Southampton
I cant really help then, just because im not 100% on how the MAF is set up, i have run a test before when the MAF just picks up airflow, regardless of the volume of the structure it is in. If the the MAF in the car doesnt give the true values of airflow through the new 80mm intake then obviously yes you'd need to scale those up. However i dont know that it would be directly proportional to the change in area of the Intake. I will have a look for an appropriate formula in some of my uni stuff and see if it will help

I would be keen to know this as well then just for info, as said before best contact Bill on here to find out.
 
Nov 2, 2004
9,334
0
South Wales
You have your measurements wrong.

MAF sizes for "ID" are 60 for ibiza, 69mm for S3/LCR and 73mm for S4. When people refer to a 3" MAF they mean external size, which is actually pointless when measureing air flow as its the ID you need.

In terms of straight size its 15% bigger from 60-69.

But its area you need, if not scaled from 60mm maf (standard) and using a 69mm maf (s3) its ~32% bigger.

What are you logging on an S3 maf?

Wilko, Bill and DPJ are your men for this.

(hope my calcs are correct. lol)
 

Prebs

Full Member
Dec 28, 2004
662
0
Norway, Bergen
You have your measurements wrong.

MAF sizes for "ID" are 60 for ibiza, 69mm for S3/LCR and 73mm for S4. When people refer to a 3" MAF they mean external size, which is actually pointless when measureing air flow as its the ID you need.

In terms of straight size its 15% bigger from 60-69.

But its area you need, if not scaled from 60mm maf (standard) and using a 69mm maf (s3) its ~32% bigger.

What are you logging on an S3 maf?

Wilko, Bill and DPJ are your men for this.

(hope my calcs are correct. lol)

Thanks for info philw

I have not done any logs yet, going on a trackday this weekend so will do some logging to see how my new map is as Im not fully happy with it.

Im running similar to Bill hybrid plus spec with a ibiza OEM sensor in the S3 housing but I dont think (suspecting) the map has bin re-scaled to put up correct values when logging with bigger housing.

So if I get this right there´s no factor/formel to use, to get the right values from actual air going throu maf with S3 housing? It must be done when writing the new map in the ECU?
 
SEATCUPRA.NET Forum merchandise