MAF position in induction system?

[Bruce]

Depends on what information the ecm uses, and how it uses it.
Personally I wouldn't mount the plastic MAFs downstream of the turbo.  They
need a certain amount of air flow for cooling, and the board in the air
stream is huge, and any trace oil on it will foul it's cooling.   The late
GM MAFs are a totally different matter in my opinion.  They also have there
own temp compensation in them.  The Bosch (least the ones used in the GNs)
need to use a MAT/IAT sensor for calc the airflow.  If all  your doing with
the MAF and IAT/MAT are air calcs then post or pre turbo is no big issue.
However, if your ecm uses the IAT/MAT for a timing corrrection then
relocating is a *great* idea in my book.
  One last area of concern is how the MAF handles whatever reversion there
is.  The turbo makes for a neat check valve, especially post turbo.  The
intake side is also subject to many more *errors* due to turbulence.
   If you go with relocating it, I for one would be interested in what you
find.  I'd also suggest you do as much before and after data logging as
possible.
   I really like having relocated mine.
Cheers
Bruce
   Lil guys back from ER, just a minor skin graft, and probably some PT.
Least the cold beer helps.



----- Original Message -----
From: "TVS" <tkmvs at bigfoot.com>
To: "DIY EFI" <DIY_EFI at lists.diy-efi.org>
Sent: Sunday, October 14, 2001 5:29 PM
Subject: MAF position in induction system?


>     Once again I would be very grateful for some advice! Is there an
optimum
> position in the induction system for a hot wire MAF for a turbocharged
> engine with intercooler? The Volvo 440 turbo has the MAF between the air
> filter and turbo, but I think I've see/read about fitting them between the
> engine and intercooler. Air mass remaining the same, but does
> response/durability change? The Bosch MAF looks quite robustly made...
> unless the plastic box is vented into the airflow!
> Thanks, Toby
>
> ********************************
> TKMVS at Bigfoot.com
> http://www.kmvs.freeserve.co.uk/index.html
> The Midget web ring:
> http://a.webring.com/hub?ring=themgmidgetwebri
> ICQ 122059845
> ********************************
>
> --------------------------------------------------------------------------
--
> To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the
quotes)
> in the body of a message (not the subject) to majordomo at lists.diy-efi.org
>
>

----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org