MAF bored. Which changes need to be done?

src · 06-09-2006, 03:55 AM

Hello!

I have a bored to 54mm MAF for my 100NX GTi.
What changes I need in my ECU program?
Just change "K" constant, or I need to modify VQ map?

Thanks!

Greg Amy · 06-09-2006, 07:03 AM

Well, if you're MAF is bored, just give it something to occupy its mind for a while. TV or Internet access usually works...

JayLew · 06-09-2006, 08:30 AM

Just the K value.

If you have access to a wideband then you might want to make sure you AF's are still correct at lower rpms.

src · 06-10-2006, 10:48 AM

Grega, ha-ha.

I like to hear how you will speak Russian.

src · 06-10-2006, 11:10 AM

Calum, I want to hear your opinion!
54/50=1.08
So I must multiply the "K" value by 1.08, right?

Calum · 06-11-2006, 01:15 AM

I like Greg's suggestion. :p

I don't remember off the top of my head. Search in this forum for a post by Jrios, he documents in a thread the right k-number to use. Its a really old post.

src · 06-12-2006, 04:45 AM

Hm.. How he found 1.05 multipler?

exxd · 06-12-2006, 12:18 PM

Shouldn't it be 1.16?

JRios · 06-12-2006, 12:33 PM

This is the thread Calum is talking about,

http://www.sr20forum.com/rom-ecu-tuning-file-exchange/98100-k-value-bored-maf-370cc-injectors.html

Now, keep in mind that the size of the maf that I was trying to do is 53.5 mm. I still have not tested this theory due to extreme lack of time. So keep in mind, like I said in my post, it has to be tested.

exxd · 06-12-2006, 12:54 PM

Bored MAF:

Area of a circle: pi * r^2

Area of 54mm maf: 2290.22mm
Area of 50mm maf: 1963.49mm

2290.22 / 1963.49 = 1.1664

The 54mm maf is 16.6% larger then the 50mm maf.

src · 06-13-2006, 04:54 PM

Yep, I think the same manner.

And as we can found here:
http://www.sr20forum.com/technical-information-library/149465-maf-size-part-s-whp-output.html

SR20DE MAF 91-94 Sentra SER, part # 53J00
50mm 250 WHP-----------Bored 54mm 290 WHP

290 / 250 = 1.16