Notices
ScoobyNet General General Subaru Discussion
Sponsored by:
Sponsored by:

Reading AFR values?

Thread Tools
 
Search this Thread
 
Old 27 September 2009, 09:07 PM
  #1  
wrxwill05
Scooby Regular
Thread Starter
iTrader: (1)
 
wrxwill05's Avatar
 
Join Date: Apr 2009
Location: Chesterfield, UK
Posts: 225
Likes: 0
Received 0 Likes on 0 Posts
Default Reading AFR values?

Hi guys,

I've recently fitted a K&N Shortram induction kit with the heatshield jobby... while i suspect everything will be OK i just wanted to make sure it wasnt sucking in too much hot-air and making engine run rich (and possibily killing it!)

whats the best / cheapest way to get some diagnostics in realtime? is there anyway I can plug my laptop into the car and get some software to plot a chart while i rag it down road..... or am i getting a bit optimistic there lmao

any ideas guys?!

Cheers
Will
Old 27 September 2009, 09:22 PM
  #2  
IMPORTPETE
Scooby Regular
 
IMPORTPETE's Avatar
 
Join Date: Aug 2006
Location: peterelliottwallandfloortiling.co.uk
Posts: 406
Likes: 0
Received 0 Likes on 0 Posts
Default

hope this helps pal
Old 27 September 2009, 09:35 PM
  #3  
mickywrx
Unmapped 12.4s @ 105
iTrader: (29)
 
mickywrx's Avatar
 
Join Date: Apr 2005
Location: Newcastle. 330bhp-289lb/ft @ 1bar boost - 12.4s @ 105mph
Posts: 11,776
Likes: 0
Received 4 Likes on 4 Posts
Post

Originally Posted by IMPORTPETE
hope this helps pal


EcuTek DeltaDash

There's also plenty of open source software available.

For checking AFR's you'll need something like this.

LM-2 Wideband O2 Digital Air/fuel Ratio Meter
Old 27 September 2009, 09:46 PM
  #4  
IMPORTPETE
Scooby Regular
 
IMPORTPETE's Avatar
 
Join Date: Aug 2006
Location: peterelliottwallandfloortiling.co.uk
Posts: 406
Likes: 0
Received 0 Likes on 0 Posts
Default

in joke mate hes my next door neighbour
Old 27 September 2009, 10:01 PM
  #5  
Scooby Jonni
Scooby Regular
 
Scooby Jonni's Avatar
 
Join Date: Nov 2008
Location: dsoc.co.nr - Dorset Subaru OC
Posts: 150
Likes: 0
Received 0 Likes on 0 Posts
Default

The cheapest way is just to pay for a dyno
Old 28 September 2009, 11:04 AM
  #6  
Midlife......
Scooby Regular
iTrader: (2)
 
Midlife......'s Avatar
 
Join Date: Feb 2004
Posts: 11,583
Likes: 0
Received 2 Likes on 2 Posts
Default

Is your's a newage?? MY05 WRX ??

If so the newage ECU will read the temp of the incoming air, compensate for density and fuel accordingly ....

Shaun
Old 28 September 2009, 05:28 PM
  #7  
wrxwill05
Scooby Regular
Thread Starter
iTrader: (1)
 
wrxwill05's Avatar
 
Join Date: Apr 2009
Location: Chesterfield, UK
Posts: 225
Likes: 0
Received 0 Likes on 0 Posts
Default

yeh it a newage mate..... so i dont need to worry about lean / rich then

on that topic... is it worth taking the resinator off the wing to help improve the airflow the IK?
Old 28 September 2009, 06:15 PM
  #8  
bluenose172
Scooby Regular
iTrader: (2)
 
bluenose172's Avatar
 
Join Date: Mar 2002
Location: Spec C - 12.5 @ 110(340/350)
Posts: 2,314
Likes: 0
Received 0 Likes on 0 Posts
Default

No that's bad advice. The ECU can only do so much with it's fuel trims to compensate, so depending on the diam of the induction kit you might want to get it checked out.
Old 28 September 2009, 07:13 PM
  #9  
Jolly Green Monster
Former Sponsor
iTrader: (4)
 
Jolly Green Monster's Avatar
 
Join Date: Jan 2001
Location: ECU Mapping - www.JollyGreenMonster.co.uk
Posts: 16,548
Likes: 0
Received 2 Likes on 2 Posts
Default

as blue says, plus the temp of the air is not the main concern but the aomunt of air and how the induction kit alters the maf sensor reading whcih the ecu uses to know how much fuel to inject and ignitiobn advance to run.

It need mapping with induction kit on there

Simon
Old 28 September 2009, 07:48 PM
  #10  
Midlife......
Scooby Regular
iTrader: (2)
 
Midlife......'s Avatar
 
Join Date: Feb 2004
Posts: 11,583
Likes: 0
Received 2 Likes on 2 Posts
Default

Surely if the MAF is in the OEM housing then the volume of air being measured by the MAF sensor does not change. All the MAF is measuring is airflow and whether the air comes from an induction kit or from the OEM induction it doesn't matter.

Or am I missing something, I usually am LOL

I've got a RCMS induction kit with a larger housing so the MAF needs re-scaling.

Is your MAF using the OEM housing ??

Shaun
Old 28 September 2009, 07:53 PM
  #11  
Jolly Green Monster
Former Sponsor
iTrader: (4)
 
Jolly Green Monster's Avatar
 
Join Date: Jan 2001
Location: ECU Mapping - www.JollyGreenMonster.co.uk
Posts: 16,548
Likes: 0
Received 2 Likes on 2 Posts
Default

the filter on the end of the maf housing effects the air flow reading..

Agreed it should be in a similar ball park with same maf housing but tend to find the maf reading is lower with less restriction on the filter and therefore the load seen by the ecu is lower and therefore it runs more ignition advance and less fuel.. bad.

Simon
Old 28 September 2009, 08:29 PM
  #12  
markjmd
Scooby Regular
iTrader: (11)
 
markjmd's Avatar
 
Join Date: May 2009
Posts: 4,341
Received 70 Likes on 50 Posts
Default

Simon
Any idea if the MAF on scoobies is hot-wire or cold-wire type?
Old 28 September 2009, 08:38 PM
  #13  
Jolly Green Monster
Former Sponsor
iTrader: (4)
 
Jolly Green Monster's Avatar
 
Join Date: Jan 2001
Location: ECU Mapping - www.JollyGreenMonster.co.uk
Posts: 16,548
Likes: 0
Received 2 Likes on 2 Posts
Default

hot
Old 28 September 2009, 11:05 PM
  #14  
Midlife......
Scooby Regular
iTrader: (2)
 
Midlife......'s Avatar
 
Join Date: Feb 2004
Posts: 11,583
Likes: 0
Received 2 Likes on 2 Posts
Default

Thanks Simon

Just looking at my RCMS induction kit I can't imagine the airflow over the area the MAF is situated is particularly "laminar" and smooth.

I guess the ECU needs to be sorted for whatever induction cone takes the air in

I was thinking back to my A level days (I'm old !!) of Bernoulli's laws and Reynolds number LOL

Reynolds number - Wikipedia, the free encyclopedia

Cheers

Shaun


Shauh
Old 28 September 2009, 11:22 PM
  #15  
wrxwill05
Scooby Regular
Thread Starter
iTrader: (1)
 
wrxwill05's Avatar
 
Join Date: Apr 2009
Location: Chesterfield, UK
Posts: 225
Likes: 0
Received 0 Likes on 0 Posts
Default

i dont understand any of that..... but it does sound nice! lol
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Sam Witwicky
Engine Management and ECU Remapping
17
13 November 2015 10:49 AM
slimwiltaz
General Technical
20
09 October 2015 07:40 PM
Wish
Computer & Technology Related
3
30 September 2015 10:39 PM
crazyspeedfreakz
ScoobyNet General
5
29 September 2015 05:04 PM



Quick Reply: Reading AFR values?



All times are GMT +1. The time now is 03:35 PM.