John and fellow vanagon types
Jim and the boys from Bostig used my 90 GL to try out an early version of
the air mass meter over-conversion kit.  I test drove the van just few miles
and was very impressed with the throttle responce.
From what I understand of Jims flow testing The new air boot shows
substancual gains verses the air boot from the stock airflow meter. This
would be a great adition to my big valve engine

Maybe Jim could refresh my memory on the airflow stats

Bob Donalds

----- Original Message -----
From: "John Bange" <jbange@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, December 07, 2005 10:16 PM
Subject: Re: Luftmassenmesser Umr�stsatz (LMU) ??

On 12/7/05, TC <trclark@shaw.ca> wrote:
>
> http://www.bostig.com/products/
> Luftmassenmesser Umr�stsatz (LMU)  COMING SOON!

Ah, the "air mass meter over-conversion kit". Presumably the hot-wire unit
with a microcontroller "interpreter" for the ECU that was alluded to some
time ago.

ok so how come no one has made this better mouse trap b4

Probably because it's a bit of a pain collecting the conversion factors.
Converting the variable-voltage output of a hot-wire AFM to the
variable-resistance output the Bosch ECU expects is probably the easy part.
Mapping out what voltage equals what resistance sounds like a big pain in
the butt, particularly because the voltage output of the hot-wire is
affected not just by the amount of air flow, but also by the temperature of
the air. ECU's designed for hot-wire AFMs compensate based on the air temp
sensor. Since the Bosch ECUs in Vanagonsdon't do that, the interface device
probably has to account for that as well. All I can say is, better them than
me!

Neat overview of electronic AFMs here:
<http://www.autoshop101.com/forms/h34.pdf>
They even explain the Karmen Vortex type sensor! Neat.

--
John Bange
'90 Vanagon - "Geldsauger"