Re-scaled MAF for a factory Housing: 2002 WRX

Casey · **Posted:** Tue Jun 03, 2008 10:42 am

I have found that my factory MAF scaling needed some adjustment for both open and closed loop. My car does have a K&N drop in filter and I have removed the intake silencer however the MAF housing is unchanged. The attached adjusted MAF scaling brought my LTFTs within 2-3% and keeps my AFR as measured with a wideband very close to the AFR requested by my primary fueling table. I have also included the factory MAF scaling for reference.

I would be curious to see what others have used for scaling on a factory MAF housing.

thefoos · **Joined:** Sat Jun 30, 2007 12:09 am **Posts:** 108

I need to be doing this. I will try to figure out how to use the MAF scaling function in rom raider and hopefully post something tomorrow...

goixiz · **Posted:** Thu Jun 05, 2008 5:52 am

i added my scaling but my range is narrower (change) because i was afraid to do that past what ive read - my first try. And i do not have a WB so im moving very slow with this

Casey: Ive attached your changes to my spreadsheet

goixiz · **Posted:** Thu Jun 05, 2008 7:20 am

I logged this AM where the temp is significantly cooler using the OEM MAF table operating in car with same route (in reverse) compared to yesterday. Change is Operating temp 73 deg compare to 95 deg F ambient

here is an additional spreadsheet

donkey · **Posted:** Mon Jun 09, 2008 10:01 am

I'm in the process of doing this myself on the stock box but with a drop in filter,resonator deleted,velocity stack and APS inlet.So far I'm on the 5th revision.Doing about 1 hr worth of driving each session.It will be kinda neat comparing this with other stock box scalings.At some point they could be averaged togehter and compared to the stock one.I have done the same rescaling to 300 g/s like Casey.

tmonahan · **Joined:** Fri Oct 06, 2006 11:06 am **Posts:** 7

Casey,

what kind of injectors are you using? What are your scaling and latency values?

Todd

Turbo_Mike · **Posted:** Tue Jun 17, 2008 6:55 pm

tmonahan wrote:

Casey,

what kind of injectors are you using? What are your scaling and latency values?

Todd

lol I got this one..

stock. stock.

Casey · **Posted:** Tue Jun 17, 2008 7:32 pm

Turbo_Mike wrote:

tmonahan wrote:

Casey,

what kind of injectors are you using? What are your scaling and latency values?

Todd

lol I got this one..

stock. stock.

bingo, haha

JSarv · **Joined:** Sat Mar 01, 2008 6:31 pm **Posts:** 696

I tested Casey's scaling, as my Intake is Stock, minus resonator box, plus a K&N Drop in.

I have a fuel pressure problem I think.... I went from a.-4.5 b.-.5 c. 1.1 D. 0 TO A.-8 B.-5.5 C. -4 D. -2.4 AFLC After rescaling the MAF with no other changes....

I used RR to log injectors and after a quick run, with more idling than driving, it suggested my injectors to be scaled at 486.6CC..... These are 100% stock injectors... I think my Walbro 255HP has ramped my static fuel pressure up about 10psi.. I am going to check it tom....

I think your scaling is real close as it brought my range of MAF correction alot tighter as well as my injector range tighter together.....

boostdog · **Joined:** Fri Aug 17, 2007 2:55 pm **Posts:** 69

What has scaling the maf done for your gas mileage? anyone have info on that?

donkey · **Posted:** Fri Feb 20, 2009 8:35 pm

JSarv wrote:

I tested Casey's scaling, as my Intake is Stock, minus resonator box, plus a K&N Drop in.

I have a fuel pressure problem I think.... I went from a.-4.5 b.-.5 c. 1.1 D. 0 TO A.-8 B.-5.5 C. -4 D. -2.4 AFLC After rescaling the MAF with no other changes....

I used RR to log injectors and after a quick run, with more idling than driving, it suggested my injectors to be scaled at 486.6CC..... These are 100% stock injectors... I think my Walbro 255HP has ramped my static fuel pressure up about 10psi.. I am going to check it tom....

I think your scaling is real close as it brought my range of MAF correction alot tighter as well as my injector range tighter together.....

Old thread bump but I think with Casey's scaling the 300 g/s voltage should be changed to around 4.71 V and the MAF voltage limit raised to 4.85V.

Casey · **Posted:** Sat Feb 21, 2009 12:22 pm

donkey wrote:

Old thread bump but I think with Casey's scaling the 300 g/s voltage should be changed to around 4.71 V and the MAF voltage limit raised to 4.85V.

Thanks for the insight on the upper end. My td04 cannot flow that high so I only made a mathematical guess for those numbers.

jc8587 · **Joined:** Sat May 02, 2009 1:37 pm **Posts:** 1

Are you guys actually seeing upwards to 4.7v at WOT?

RomRaider

Re-scaled MAF for a factory Housing: 2002 WRX

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