Re: fifth-gear and miles per gallon [CIS-E]

["Marc Peterson" <mpeters6@rochester.rr.com>]

Ah,...the ratio doesn't change much, the total quantity does, makes sense.

Motronic has MAS, TPS, cam position sensor, egr temp sensor, 1 or 2 Ox
sensors, air temp sensor, coolant sensor, 1 or 2 knock sensors, etc.  You
should see the number of connectors on a A3 VR6 harness. :)

Marc
----- Original Message -----
From: "16V Jason" <jason@scirocco.org>
To: "Marc Peterson" <mpeters6@rochester.rr.com>; <scirocco-l@scirocco.org>
Sent: Wednesday, October 31, 2001 5:17 PM
Subject: Re: fifth-gear and miles per gallon [CIS-E]


> At 04:48 PM 10/31/2001, Marc Peterson wrote:
> >Assuming no enrichment is used...
>
> Right...
>
>
> >All CIS/CIS-E engines mixed by the air flow meter flap.
>
> Right!...
>
>
> >   If the engine is
> >running at a given RPM, it is pumping a fixed amount of air though it, so
to
> >my understanding 3000 rpm is the same amout of fuel whether it is 1/2 or
3/4
> >throttle, the mixture doesn't change based on the throttle position.
>
> Oh! So close! :)
>
> You're totally right --mixture is determined by air flow sensor.  So the
> mixture (proportion of fuel per air) should stay relatively constant
> through the rev range.  However, at higher throttle openings, the engine
> moves more air, and thus more fuel.
>
> >This is different on Motronic system, obviously.  They have a throttle
> >position sensor.
>
> I'm not all _that_ familiar with Motronic, but I'd be surprised if all it
> had is a throttle position sensor -- doesn't it have a mass airflow sensor
> as well?  I'm pretty sure every single modern fuel injection system uses a
> mass airflow sensor to determine how much air is going in, and then
> correlates that with throttle position for a number of reasons (to richen
> mixture during abrupt throttle movements, full throttle enrichment, etc
etc).
>
> Jason
>
>
>
>
>
> >I think the above is right.
> >
> >Marc
> >----- Original Message -----
> >From: "Fry, Larry" <LEF@chem-tronics.com>
> >To: <scirocco-l@scirocco.org>
> >Sent: Wednesday, October 31, 2001 4:33 PM
> >Subject: fifth-gear and miles per gallon
> >
> >
> > > Hypothetical situation: you have fifth-gear ratio that gives 3800rpm
at
> > > 80mph and it takes 1/4 throttle to maintain that steady speed.
> > > second hypothetical situation: you have, on the same car, on the same
> > > stretch of road, a fifth-gear ratio that gives 3000rpm at 80mph but it
> >takes
> > > 1/2 throttle to maintain that steady speed.
> > >
> > > question: which situation yields the best mileage?
> > >
> > > In other words, which influences miles-per-gallon more, rpm or
throttle
> > > position?  Or is it pretty much a wash?
> > >
> > > Inquiring minds......
> > >
> > > Larry  sandiego16V
> > >
> > > [Disclaimer]This e-mail is strictly confidential and intended solely
for
> >the
> > > addressee. It may contain information which is covered by legal,
> > > professional, or other privilege. If you are not the intended
addressee
> >you
> > > must not use, disclose, or copy this transmission. This E-mail is not
> > > intended to impose nor shall it be construed as imposing any legally
> >binding
> > > obligation upon GKN Aerospace Chem-tronics Inc. and/or any of its
> > > subsidiaries or associated companies. Neither GKN Aerospace
Chem-tronics
> > > Inc. nor any of its subsidiaries or associated companies gives any
> > > representation or warranty as to the accuracy or completeness of the
> > > contents of this E-mail. GKN Aerospace Chem-tronics Inc. shall not be
held
> > > liable to any person resulting from the use of any information
contained
> >in
> > > this E-mail and shall not be liable to any person who acts or omits to
do
> > > anything in reliance upon it.
> > >
> > >
> > > --
> > > Email LIST problems to: scirocco-l-probs@scirocco.org.
> > > To unsubscibe send "unsubscribe scirocco-l" in the message to
> >majordomo@scirocco.org
> > >
> > >
> >
> >
> >--
> >Email LIST problems to: scirocco-l-probs@scirocco.org.
> >To unsubscibe send "unsubscribe scirocco-l" in the message to
> >majordomo@scirocco.org
>
>
> --
> Email LIST problems to: scirocco-l-probs@scirocco.org.
> To unsubscibe send "unsubscribe scirocco-l" in the message to
majordomo@scirocco.org
>
>


--
Email LIST problems to: scirocco-l-probs@scirocco.org.
To unsubscibe send "unsubscribe scirocco-l" in the message to majordomo@scirocco.org