Date: Thu, 1 Dec 2005 11:37:03 -0800
Reply-To: mailinglist@FASTFORWARD.CA
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Marshall <mailinglist@FASTFORWARD.CA>
Organization: Fast Forward Automotive
Subject: Re: Fuel flow senders
In-Reply-To: <438F45C7.2010501@comcast.net>
Content-Type: text/plain; charset="iso-8859-1"
Your solution sounds good but it really means establishing a constant link
with the ECU and it also assumes the ECU is correct. On VWVortex there have
been people doing this with a VAG-COM with their TDIs and 1.8Ts, but
reliable results assumes that everything is stock and you want to drive with
a lap top everywhere. This is also bypassing the built in functions of a
gauge that already has the features that I want. The big issue with the
TDIs is you can change the variable for the Injection Quantity (IQ) for the
ECU. It can be set at 2.1 to 9.0mg per injection at "warm idle" - this
means this variable must match what the injectors are really doing for
everything else to be correct. Stock is pretty close, but my motor and this
customer's motor isn’t stock as we are running much larger injectors and
custom software to match. You can change the IQ to fine tune the amount of
"smoke vs pedal response" you want to have - this means skewing what the ECU
really thinks it is injecting so it will guarantee that you get the wrong
results!
David Marshall
Fast Forward Automotive Inc.
4356 Quesnel-Hixon Road
Quesnel BC Canada V2J 6Z3
Internet: http://www.fastforward.ca Phone: (250) 992 7775 Email:
sales@fastforward.ca
- Engine Conversions and Accessories for classic water-cooled Volkswagens
- Electrical harness fabrication and customization
Due to the large quantity of email we receive, please include previous email
correspondence when replying.
This will allow us to read the full dialogue in one message so that we my
provide you a quicker and more accurate response.
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Marc Sayer
Sent: December 1, 2005 10:50
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Fuel flow senders
This is best handled as purely a software solution. The injector pulse
length, static capacity rating, and real-time fuel pressure can all be
used to determine consumption at any given moment, and that info can be
used to compute mileage figures real-time, for a specific trip, or for
an overall average. Basically the injectors are used as the flow meters.
Many newer FI systems already incorporate this into their EMS. Since
the data collected is the fuel passed through the injectors, rather than
through the fuel lines, as your TriStar's system uses, the return flow
is eliminated from the equation right off the bat.
David Marshall wrote:
>Volks,
>This series of questions involves for me a Diesel TDI engine, but the same
>principals are involved with a fuel injected gasoline engine, so hence the
>cross-posting.
>
>We are going to be starting on a TDI conversion that I want to "kick up a
>notch" as far as instrumentation goes. The eight function gauge that I
have
>installed into our TriStar has the ability to use a few flow meter so that
I
>can view the instantaneous amount of fuel being consumed by the engine.
The
>problem is I can't see how to connect the fuel meter so that I can get an
>accurate reading. The meter is basically a little "box" with a fuel input
>and output on it and it will give an electronic "pulse" per every unit of
>fuel that flows trough it. The gauge attached to it counts the pulses and
>determines fuel flow from the amount of pulses over time. Now as we all
>know, modern Diesel and Fuel Injected gasoline engines has an input from
the
>fuel tank and any fuel it doesn't use goes back to the tank. As a result,
>the line from the tank to the engine doesn't show the real fuel consumption
>as there is always fuel going back to the tank. A the to and from lines
are
>never a constant difference ratio, the only thing I can see doing is loop
>the engine's fuel output into the input of the fuel pump instead of back
>into the fuel tank. The main reason why we dump fuel back into the tank is
>it makes the system self bleeding system by removing air bubbles. Air
>bubbles are bad for fuel pumps. The other reason for fuel being returned
to
>the tank, especially in a Diesel is it cools the fuel off as the TDI will
>give less power if the fuel is too hot - hence the fuel coolers on the pump
>düse engines. So basically I am wondering if there is any such thing as a
>"bubble trap" out there to prevent air bubbles from being trapped in the
>system and if there is a way that I am missing about installing fuel
>metering devices?
>
>For a picture of our prototype engine monitoring gauge see:
>
>http://www.fastforward.ca/gallery/1005instrumentpod.jpg
>
>Cheers!
>
>David Marshall
>
>Fast Forward Automotive Inc.
>4356 Quesnel-Hixon Road
>Quesnel BC Canada V2J 6Z3
>
>Internet: http://www.fastforward.ca
>Email: sales@fastforward.ca
>
>- Engine Conversions and Accessories for classic water-cooled Volkswagens
>- Electrical harness fabrication and customization
>
>
>
>
--
Marc Sayer
Journalist, Photographer, Dog Trainer (APDT member #062956)
Board member - Western States Great Dane Rescue Association
Director of Operations & Training - Deaf Dane Rescue Inc.
Springfield, OR USA
My Homepage - http://gracieland.org
Deaf Dane Rescue Homepage - http://gracieland.org/DaneRescue/
--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.362 / Virus Database: 267.13.10/189 - Release Date: 11/30/05