Air Flow Meter

[Kevin Rutledge]

>I'm installing a Rover 3.9 injection engine into a vehicle I race 
>off road, I need to relocate the air flow meter my question is 
>
>Does it matter how far it is from the throttle body, the Std 
>system has it on the end of a bit of flexi pipe approx 200mm long, 
>this is not quite long enough for me to mount it easily, I've 
>either got to get it much closer (30-40mm) or a little further 
>(maybe 300mm which would suit the installation better)
>
>It would also be better (from an installation point) if I use a 90 
>degree elbow between it and the throttle body, Will this matter?
>

This distance an air flow meter is from the throttle body really doesn't
make any difference.  you need to make sure there are no air leaks between
the air flow meter and the throttle body.  Also make sure the air flow
meter is no subject to much engine vibration (make the tubing flexible).  

I would not recommend a 90 degree turn or any other sharp turn for intake
air flow, especially near air flow meters, the air flow characteristics
change substantually with bends like that and some air flow meters won't
sense air flow quite the right way (Bosch's hot wire is one).

Kevin Rutledge
Saab/Volvo Technician