Accord 04 mileage improved if in-coming air is heated?

Elle wrote:
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I was going ot avoid jumping in but I just can;t keep my fingers still.

I have a 1991 MT Honda Civic.

In an attempt to improve my understanding of modern engine control
systems
I built and added a PWM to the both injectors. I have a dual point so
my
car has a primary and secondary, AKA main and aux.

I have watched as the dwell time of the injectors increased as cooler,
then
cold weather arrived. I decided to try a siple experiment last week
when the
temps got down to 20F. I added a piece of flex tubing to restrict the
inlet
air to air warmed by the radiator. Guess what, the injector dwell time
went
back down to the lower values of mid summer.

I also have a g-meter, accelerometer so I can make some estimates
better then
WAGs about performance. Get into 2nd at 15MPH and floor it.Very
revealing.


The increase due to cold is on the order fo 10 to 15%.
So I have to conclude that cold air hurts millage, but I agree it does
boast
performance.

Like many things in life, kind of pardoxical.

Terry

Terry

 

AFAIC, these are wonderful experiments.

From them, I gather the intake air temperature signal to the engine computer
tends to dominate, compared to the coolant temperature signal.

So if I have it right, in cool weather, the injector duration ordinarily is
higher than in hot weather, and so more fuel per cycle is dumped into each
cylinder in cool temperatures. I presume this is to bring the engine up to
normal operating temp, and maintain it there, quicker. With cooler and so
denser air, more air is packed in as well. So one gets more power, but as
you imply, more power doesn't necessarily translate to greater efficiency
miles per gallon-wise.

Something like this...

Note for those new to the thread: Below I actually meant the higher wind
resistance in winter, due to more dense air, will decrease fuel mileage, as
will other things.

 

Yup. PV = nRT

What do you want? Obviously barometric pressure will vary with
elevation (as opposed to altimeter and barometer settings which are
based on the corresponding pressure at sea level). Assuming that you
are not changing elevation/altitude radically, meteorological changes
in barometric pressure are pretty negligible for the purpose of
approximating air density. If you are driving from New York to
Denver, or climbing from sea level to 5000 feet MSL, it will be a
factor. What is your point?

Only if they give different results from this one. Otherwise it would
be superfluous.

You were the one claiming that weather fluctuations (other than
temperature) are going to affect air density by 10%. I am merely
pointing our that you are off by an order of magnitude. Live with it.

Really? It is what I and many others have learned through logic,
training and direct experience. It is hardly a secret except maybe to
you.

I was giving you the benefit of the doubt that you aren't so stupid
that you think cold air decreases engine performance. Perhaps I was
wrong to do that.

I would recommend you get some then.

 

http://wwwrsphysse.anu.edu.au/~amh110/Intercooler/volvo_intercooler.htm

 

eh? that's totally untrue. you want a list of si turbo engines with
intercoolers?

you're confusing mixture with air intake.

you should. that way you'll stop making mistakes.

wishy washy nonsense.

 

Elle wrote:

Great sig, okay if I use it?

 

It's not a complex with some.

 

No problem.