Aftermarket intake questions

"Richard Phillips" > wrote:

> Usenet wrote:
>> P.S. My 91 with over 210,000 miles doesn't use significant oil,
>> still shows good compression, and drives just fine even though
>> I've been using a K&N filter, which is cleaned and reoiled every
>> 30,000 miles.
>
> Just out of interest, how many of those miles were with the K&N
> filter? I've just bought one (Typhoon) so anything that makes me
> feel happier about it's filtering ability is good

K&N actually filters slightly better than OEM. There's a very large
amount of FUD about K&N filters, one being that they allow dirt in the
engine which is untrue and the other that they will give big increases
in HP which is also untrue although if you have an unusually
restrictive intake system (Miatas don't) the K&N will help.



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"nosfatsug" > wrote:

> There is simply too much obfuscation so, I'm starting with a clean
> slate.

Yes, let's get the facts straight. You NEED to get an aftermarket
intake system otherwise the manufacturers won't make money and the
world economy will collapse so get one right away, do your part to
avoid the end of civilization.

That should be clear and free of obfuscation, right?



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"XS11E" > wrote in message
. 184...
> "nosfatsug" > wrote:
>
>> There is simply too much obfuscation so, I'm starting with a clean
>> slate.
>
> Yes, let's get the facts straight. You NEED to get an aftermarket
> intake system otherwise the manufacturers won't make money and the
> world economy will collapse so get one right away, do your part to
> avoid the end of civilization.
>
> That should be clear and free of obfuscation, right?
>

I couldn't agree with you more. After all, that's what a free market
economy is all about. The choice whether to spend hard earned cash on a
product is 100% up to the buyer. And since we are all individuals with free
choice, our individual decisions may be different with neither being better
than another, just different. The best we can do is make sure that facts
are available for people to make wise decisions. The worst would be for
everyone to stop make decisions to wisely spend their money because the
facts were obfuscated. That is when our economy and the world would
collapse. So yes, go out and spend your hard earned cash today for the good
of the country and the world, but first do the research, learn the facts,
and spend our money wisely.

Gus

"nosfatsug" > wrote:

>
> "XS11E" > wrote in message
> . 184...
>> "nosfatsug" > wrote:
>>
>>> There is simply too much obfuscation so, I'm starting with a
>>> clean slate.
>>
>> Yes, let's get the facts straight. You NEED to get an
>> aftermarket intake system otherwise the manufacturers won't make
>> money and the world economy will collapse so get one right away,
>> do your part to avoid the end of civilization.
>>
>> That should be clear and free of obfuscation, right?
>>
>
> I couldn't agree with you more. After all, that's what a free
> market economy is all about. The choice whether to spend hard
> earned cash on a product is 100% up to the buyer. And since we
> are all individuals with free choice, our individual decisions may
> be different with neither being better than another, just
> different. The best we can do is make sure that facts are
> available for people to make wise decisions. The worst would be
> for everyone to stop make decisions to wisely spend their money
> because the facts were obfuscated. That is when our economy and
> the world would collapse. So yes, go out and spend your hard
> earned cash today for the good of the country and the world, but
> first do the research, learn the facts, and spend our money
> wisely.

Oh, LORD NO! If we were spending our money wisely nobody would have a
Miata at all!!!! We'd all be driving vanilla 4 door sedans with wimpy
4cyl engines and avoiding all luxuries of all kinds.... if people knew
the facts nobody would buy 90% of the products available today so.....
let's just keep on buying ignorantly, the economy NEEDS unwise buyers
and people who don't understand the economy, that's what keeps the
lottery healthy, that's what keeps the payday loan business afloat,
thats what maintains finance companies......

Geez, man, stop preaching intelligence, our economy is designed to run
w/o it and cannot survive educated consumers.




--
XS11E, Killing all posts from Google Groups
The Usenet Improvement Project: http://blinkynet.net/comp/uip5.html

"nosfatsug" > wrote:

>There is simply too much obfuscation so, I'm starting with a clean slate.
>What I hear Leon saying is that at any given velocity of a car, lets say a
>Miata for interest of this group, the power output from the engine is the
>same, assuming all other external factors are the same (e.g., engine
>modifications don't change the profile and thus the drag of the car).
>Also, assuming similar fuel mixture in the combustion chamber (which is
>controlled by the ECU to meet exhaust and performance criteria),

Yes so far.

> the amount
>of air entering through the intake system stays the same (e.g., same power,
>same fuel to air ratio, and therefore same air volume).

No, this misses the exact point. It is the *amount of oxygen*, not the *volume*
that stays the same. By design a Miata engine wants to take in 1.8 L air by
volume every cycle. When it really needs only a fraction of that, during
highway cruise, say, the throttle keeps out the excessive air. That means
that the engine fights the throttle, which costs power, hence fuel. Now if the
intake air goes down say 30 C in temperature, the volume that the engine needs
becomes even smaller by about 10 percent. So the throttle must let the engine
get even less volume, so they fight harder, so fuel consumption goes up.

Leon


> Thus, the throttle
>plate in the air intake will be further closed in a less restrictive air
>intake system compared to stock.
>
>Now for the difficult part. I believe Leon is stating that at constant
>power output, the engine with the less restrictive intake system will need
>to work harder to pull in the air due to lower vacuum needed to pull the
>same volume across the trottle plate. Put another way, more fuel is needed
>to the same net power output to the wheels since more power is used to pull
>air into the enginer. If this is the case, then I can understand Leon's
>argument. For maximum fuel efficiency, the intake system should be designed
>to minimize pumping losses at the designed optimum speed.
>
>What I don't understand, is why moving restriction from the intake system to
>the throttle plate results in the engine having more pumping losses. I
>understand that the pressure loss across the throttle plate will increase,
>but at the same time, the pressure loss across the rest of the system is
>less. Therefore, couldn't the vacuum down stream of the throttle plate to
>be the same in both cases. Why isn't it the other way around where the
>restriction across the throttle plate actually results in less total
>pressure drop than the restricted intake system?
>
>Now, of course, this entire argument is only valid for the steady state case
>(e.g., the car at constant velocity and the engine at constant power
>output). From my experience, even at what appears to be constant velocity
>(e.g., driving on the highway at say 65 miles per hour), the engine output
>varies to adjust for other factors (e.g., incline of the road, wind, passing
>cars, etc.). Average fuel consumption is thus the average overtime as the
>engine output and thus fuel efficiency vary to maintain constant speed.
>
>Gus
--
Leon van Dommelen Bess, the Miata Bozo, the Miata
http://www.dommelen.net/miata
The only thing better than a white Miata is two white Miatas

"Dana Rohleder" > wrote:

>
>"Leon van Dommelen" > wrote in message
.. .
>> "Dana Rohleder" > wrote:
>
>Leon,
>
>>>My
>>>initial question to the group was, who has tried an aftermarket intake,
>>>and
>>>what was the result?
>>
>> In your original post you stated,
>>
>> "Logic tells me that the intake would increase the fuel economy even
>> more."
>> and I asked "What logic?"
>
>True. What you did was obfuscate a simple question by attempting to send the
>discussion in several directions that do nothing to answer the inital
>question(s).

You posted the above remark in a public newsgroup. It is definitely wrong.
You get the facts. Thanks are not necessary since I too post to a public
newsgroup.

> If you don't have an answer to the question(s) asked, why do
>you hinder the process by confusing the isuue - answering simple questions
>with divergent questions? I have plenty of my own reasons for not purchasing
>a system to date; I am simply trying to get real-life information/data from
>owners who have actually tried the systems and have opinions on the results.
>
>>> My intention was to get actual information from people
>>>who have actually tried these systems, not to spend a bunch of everyone's
>>>time mentally masturbating in a virtual circle jerk.
>>
>> I did not make any personal remarks at your address. Why do you do it at
>> mine?
>
>I was talking about myself starting a useless thread - why would YOU take
>the comment personally?

I think it would not be obvious to everybody that you were addressing
this to yourself. Note the reference to spending people's time. That was
the thing I was doing, remember? With good justification, and this is
a public newsgroup, so I can. But anyway.

Leon
--
Leon van Dommelen Bess, the Miata Bozo, the Miata
http://www.dommelen.net/miata
The only thing better than a white Miata is two white Miatas

In article >,
(Leon van Dommelen) wrote:

> "nosfatsug" > wrote:
>
> >There is simply too much obfuscation so, I'm starting with a clean slate.
> >What I hear Leon saying is that at any given velocity of a car, lets say a
> >Miata for interest of this group, the power output from the engine is the
> >same, assuming all other external factors are the same (e.g., engine
> >modifications don't change the profile and thus the drag of the car).
> >Also, assuming similar fuel mixture in the combustion chamber (which is
> >controlled by the ECU to meet exhaust and performance criteria),
>
> Yes so far.
>
> > the amount
> >of air entering through the intake system stays the same (e.g., same power,
> >same fuel to air ratio, and therefore same air volume).
>
> No, this misses the exact point. It is the *amount of oxygen*, not the
> *volume*
> that stays the same. By design a Miata engine wants to take in 1.8 L air by
> volume every cycle. When it really needs only a fraction of that, during
> highway cruise, say, the throttle keeps out the excessive air. That means
> that the engine fights the throttle, which costs power, hence fuel. Now if
> the
> intake air goes down say 30 C in temperature, the volume that the engine
> needs
> becomes even smaller by about 10 percent. So the throttle must let the
> engine
> get even less volume, so they fight harder, so fuel consumption goes up.

No.

Because while resistance goes up, the speed of the flow goes down. And
power required to overcome the resistance to the flow is proportional to
the *square* of the speed of the flow, but only directly proportional to
the friction.

IOW, double the density of the air, you halve the required flow by
doubling the resistance. Thus you get an increase by a factor of two
from change in resistance, but a decrease by a factor of four from
change in flow, for an overall decrease in pumping losses by a factor of
two.

--
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling four feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect if you
sit in the bottom of that cupboard."

>>> "nosfatsug" > wrote:
>
>> So yes, go out and spend your hard
>> earned cash today for the good of the country and the world, but
>> first do the research, learn the facts, and spend our money
>> wisely.
>
"XS11E" > wrote in message
84...
>
> Oh, LORD NO! If we were spending our money wisely nobody would have a
> Miata at all!!!! We'd all be driving vanilla 4 door sedans with wimpy
> 4cyl engines and avoiding all luxuries of all kinds.... if people knew
> the facts nobody would buy 90% of the products available today so.....
> let's just keep on buying ignorantly, the economy NEEDS unwise buyers
> and people who don't understand the economy, that's what keeps the
> lottery healthy, that's what keeps the payday loan business afloat,
> thats what maintains finance companies......
>
> Geez, man, stop preaching intelligence, our economy is designed to run
> w/o it and cannot survive educated consumers.
>

You know, I think you are right. I should have suggested maximizing
personal satisfaction and enjoyment not the use of wisdom. Forgive my poor
choice of words.

Gus

"Leon van Dommelen" > wrote in message
...
> "nosfatsug" > wrote:
>
> No, this misses the exact point. It is the *amount of oxygen*, not the
> *volume*
> that stays the same. By design a Miata engine wants to take in 1.8 L air
> by
> volume every cycle. When it really needs only a fraction of that, during
> highway cruise, say, the throttle keeps out the excessive air. That
> means
> that the engine fights the throttle, which costs power, hence fuel. Now
> if the
> intake air goes down say 30 C in temperature, the volume that the engine
> needs
> becomes even smaller by about 10 percent. So the throttle must let the
> engine
> get even less volume, so they fight harder, so fuel consumption goes up.
>
Leon,

You are right, the important variable is mass of oxygen not volume of air.
I was being lazy in my analysis and basically assuming the conditions were
similar enough that the density didn't change signficantly. I also
understand that the same mass of oxygen requires less volume of dense air.
How significant is the reduction in fuel efficiency with lower intake air
temperature? Do cars get lower gas mileage in the winter in cooler
climates?

I still do not understand your point for the case when the temperature is
the same and the only change is a less restrictive intake leading to more
restriction across the throttle plate. I do understand that fuel efficiency
is impacted by pumping loses, which a greater at low power when the throttle
is closed, and by friction loses which increase with engine speed. I also
understand that more restriction across the intake system (e.g., closing the
throttle) results in more pumping loses. What I don't understand is why it
matters where the restriction is in the intake system. I'd think that what
would matter is the restriction across the entire intake system not just the
throttle. What am I missing?

Gus

Bruno wrote:
> Richard Phillips wrote:
>>
>> I'd be very interested to see the results, if you could post them up!
>>
> Here is an appetizer: http://users.cybercity.dk/%7Edsl45720/rulle.JPG
>
> It's the test before any changes so we are talking a 1999 1.8 with
> aprox. 60,000 miles on the clock and no alterations to Mazda specs
> except it has a Remus exhaust.
>

Interesting, it's what I expected, only more so! Although that is a torque
graph, I'd be interested to see the BHP equivalent (although I would expect
similar curves).
My car is a 2002 1.8, approx 59,000 miles on the clock, no alterations
expect for a Racing Beat exhaust. This test might as well have been done on
my car...

>
>> I've just got myself a 2nd hand (6 months old) Typhoon for my 2002
>> 1.8, hopefully I'll be fitting it in the next couple of days. I'm
>> not expecting anything spectacular but I was curious and I got it
>> much cheaper than new price, I just had to scratch the itch, you
>> know?!
>
> Supposedly it's real easy to fit so if you got it cheap there
> certainly is no reason not to try. Just make sure to keep the
> original parts in case you don't like the new sound (or performance
> somehow suffers).
> Kind regards
> Bruno

I'll try it and see, may well be standard again next week though :-p

Cheers,
R.