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Improving air intake flow for better MPG?
Topic Started: Aug 23 2014, 12:55 AM (1,977 Views)
rjsdotorg
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R E Member

Extra CFM will do less, if anything, than other things for mpg.
Most things that reduce the part-throttle O2 volume, increase MPG: EGR, heated intake bypass, advanced XFI cam etc.
A big part is the reduced pumping losses against the throttle plate. We only need ~10HP at cruise
http://ecomodder.com/forum/tool-aero-rolling-resistance.php
so that just cracked throttle become significant, apparently.
Pumping loss is also proportional to RPM, so lower cruise rpm helps there, as well as internal wall frictions etc.

I think the ideal would be a massive EGR for FE, combined with supercharger for WOT power, each enabled as needed.
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Metromightymouse
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Powdercoat Wizard

Here is a follow up email from them with her email at the top. I was a little surprised to get an email from K & N when I was dealing with Spectre. Perhaps when there is a complaint they use a spoofed email but I kinda doubt it. Click on the pic to get a bigger size that you can read.

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Everything says Spectre except her email which uses the knfilter.com extension. You decide what it means, but I will withdraw my statement as an absolute and change it to possibly made by K&N. I wish I had a copy of the UPS label, I don't remember where they had me send the broken one.

And If anyone is thinking I am making something up to try to cover something I posted, I don't have the spare time to spend doing dumb stuff like that. I am not afraid to admit when I'm wrong, it isn't the end of the world when it happens. The human mind is fallible and it is what I was equipped with, so I gotta work with what I got.
Edited by Metromightymouse, Aug 23 2014, 01:17 PM.
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Freeman
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The Family Man

I think a smooth intake runner would help intake velocity and possibly improve throttle response. Other than that, I do not think you will see economy gains from something like this. Even the throttle response could be argued as a non-economy change.
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92blumetro
jack of all trades, master of two

all I notice is more noise and garbage on my filter if I take the snorkel tube off....if you run at 6500 rpm all day it might make a difference, but what about the fuel mapping- does that change slightly to make up for the extra air? I don't know. Richard (t3 ragtop) seems to have decent luck with his set-ups, check out his posts/ pictures.
but I know for a fact it makes a difference on my turbo car, but that's a completely different ballgame there.
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thresher shark
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Fresh Fish...mmmm....tasty!

My former commute (one way) was 57 miles, 48 on the freeway at about 68 to 70 mph, the rest was driving through town 25 to 35 mph, and secondary highway 55 mph. Removing the snorkel and a throttle-body bridge delete allowed me to climb a couple of modest hills on the freeway without downshifting. There was no change in fuel economy. I have fuel economy data for about 1 year before and 1 year after the change
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t3ragtop
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Turbo3 and Twincam Tweaker

i say the same thing over and over every time a newb gets the idea to fiddle with their induction system. :P

cold air induction on a g10 doesn't make a bit of difference. the intake manifold and throttle body is heated. some of the later model (mk4) cars even have electric pre-heaters. as soon as cold air hits the throttle body it gets heated back up.

there's always the quick responses from the cai crowd about air density, blah, bla, blah. :D

anything that you can do to get more air into the induction system is good. i draw the line on that statement where someone adds corrugated (convoluted) clothes dryer hose to the front of their car and calls it "ram air." over the 40 years i have spent with car i can point to many examples of various makers preferring "quieting boxes" on their induction systems and all the way to modern helmholtz tuning. varying induction air pressures leads to inaccurate responses from the ecu in controlling injection. in the way back, it played havoc with carburetor jetting, too.

there's always the expected responses from the "ram air" crowd. :D

what i liked and what i recommend for hot rodding a g10 is to use the old moroso triangular air filter, it has been discussed many times, along with the throttle bridge delete also discussed at length many times. the best current pics and explanation of the triangular air filter can be found in snowfish's project threads. since i did that many years ago, most of my posts and pics have been lost to time.

pretty much anybody i've ever known that actually did the short length, direct flow induction liked it.

underhood heat that has been discussed ad nauseum for the last 10 years is a myth. it has been scientifically dispelled as such. while the car is moving the underhood temps are within 1 or 2 degrees of the ambient outside air temperature. the latest synapsis of the instrumentation and data acquisition for under hood temps is in one of calrenman's threads.

the key is to reduce induction tube length to vanishing and remove everything that represents a flow restriction. the small gain in air flow is decoupled from engine rpm and is fully compensated in fueling by corrections made automatically by the engine management system. from that point you are free to make whatever other changes to the engine that you want as the induction system is nearly completely decoupled from any echo you might get from the engine in operation.

almost every car has an induction set that is tuned to the engine and peaks at some rpm. small diameters and long lengths are okay for low rpm operation and have some advantage for locating torque at low rpm. they also choke the crap out of air flow. larger diameter piping tends to slow air velocity but it is also less restrictive. zero piping lets the engine select its appropriate tuning for any rpm. no induction pipe neither induces low end torque nor slows air velocity.

i tend to operate engines in the higher rev range. the smaller the engine (lower displacement) the more inclined i am to use the higher rpm to supply torque. that is markedly so on a normally aspirated g10. the hamsters are small but whipped sufficiently they can be quite effective. :P

g10 engines i have set up the way i like 'em turn in repeated 42 mpg mileage numbers even though i run the dog snot out of them. :)

with the induction set mentioned above the engine can take in whatever amount of air it needs to at any given time. if you run an xfi grind cam and do the hyper miler thing you may as well just leave the induction system alone. buy a new air filter or whatever but you probably wouldn't ever need the kind of wind the custom induction allows. if you run a stock base model cam or a bumpstick that moves the action up in the rpm range you will gain performance from the high flow mods.

and that's my 2 cents. ;)
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Cubey
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t3ragtop
Aug 25 2014, 05:03 PM
i say the same thing over and over every time a newb gets the idea to fiddle with their induction system. :P
Anything more than "no" is a huge waste of keystrokes, especially since we're now on page 2. I already stated acceptance that it won't help a Metro on page 1. :P
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t3ragtop
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Turbo3 and Twincam Tweaker

if it were only that simple, cubey. :D

no isn't the answer and there were other people involved in the discussion, which i took the time to read.

besides, they were my keystrokes. didn't cost you a dime. :P
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happydriver
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Sedan Love

I just unhooked my factory snokel from my breather. Ill see if it makes a difference in my four banger. If not Ill just reinstall it. I hope it helps some like ragtop says.
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Freeman
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The Family Man

t3ragtop
Aug 25 2014, 05:25 PM
if it were only that simple, cubey. :D

no isn't the answer and there were other people involved in the discussion, which i took the time to read.

besides, they were my keystrokes. didn't cost you a dime. :P
I stand corrected, possibly?

I wouldn't bother with it because it's a Metro. They are designed fairly competently.
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jonathan180iq
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Not Really All That Smart

I've run two types of open air filters - one modified stock and the other is the fabled Edelbrock :)

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IMG]http://i60.tinypic.com/255md6o.jpg[/IMG]

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I have also gathered a couple thousand miles worth of data regarding under-hood temps, ambient air temps, and intake temperature temps...

What I've gathered goes something like this:

When the ambient air temperature is less than 85*F, the under-hood temps will not eclipse 107*F while moving.
When the ambient air temperature is greather than 85*F, the under-hood temps will not eclipse 118*F while moving.

Rain severely helps in the cooling process - dropping under hood temps as much as 20*.

Even at a red light on the hottest day, I have never seen temperatures under my hood get higher than 124*F.
I live in Georgia, and it's muggy, hot, sticky, sweaty and gross pretty much all the time during the summer. Once I'm driving under-hood temps sit around 95*F.

Considering that our average summer heat is between 93* & 98*, the claims made by T3Ragtop are confirmed by this data set.

I have no way to electronically test my intake set ups for flow outside of what information is gathered by my live ODB system reader. It is easier to maintain a lower intake manifold absolute pressure with the unrestricted Edelbrock filter than it is with the modified stock air filter housing. It is also easier with the modified housing as opposed to the stock set up. I have tested all three. For what it's worth, absolute manifold pressure work like a reverse vacuum gauge - the lower the number the higher the fuel economy numbers at any given speed. For example, an absolute manifold pressure between 2-4 PSI results in fuel economy numbers that are equivalent to a video game. regular cruising, on flat ground, around 45mph, results in a more moderate range. 4-6 PSI will results in an average fuel economy rating around 50MPG. Between 8-10 PSI, mileage drops into the mid 20s to mid 30s range. Downhill at full throttle, I cannot achieve an absolute manifold pressure greater than 11.

The lower numbers are easier to maintain, as mentioned, with the open filter as opposed to anything else. It takes more feathering of the throttle to maintain a certain pressure range, based on restriction.

What this tells me is that, again, the claim made by T3 that the best thing (for any engine) is to be as open and unrestricted as possible. Get the inlet mouth as close to the point of injection as possible and then move onto something else.

I cannot claim an actual fuel economy increase since the filter change, because at the same time I also advanced my timing and opened my exhaust, leaving me with too many variables to have one narrowed down for accuracy. I suspect that the advance timing has more to do with my latest fuel economy increases than anything else.
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davegran
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jonathan180iq
Aug 26 2014, 07:29 AM
I've run two types of open air filters - one modified stock and the other is the fabled Edelbrock :)

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....

The lower numbers are easier to maintain, as mentioned, with the open filter as opposed to anything else. It takes more feathering of the throttle to maintain a certain pressure range, based on restriction.

What this tells me is that, again, the claim made by T3 that the best thing (for any engine) is to be as open and unrestricted as possible. Get the inlet mouth as close to the point of injection as possible and then move onto something else.
I wondered if either you or T3 had experimented with intake flow straighteners, like a radius lip or a short tapered trumpet/velocity stack on the intake.

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Posted Image
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Coche Blanco
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davegran
Aug 26 2014, 02:20 PM
jonathan180iq
Aug 26 2014, 07:29 AM
I've run two types of open air filters - one modified stock and the other is the fabled Edelbrock :)

Posted Image
....

The lower numbers are easier to maintain, as mentioned, with the open filter as opposed to anything else. It takes more feathering of the throttle to maintain a certain pressure range, based on restriction.

What this tells me is that, again, the claim made by T3 that the best thing (for any engine) is to be as open and unrestricted as possible. Get the inlet mouth as close to the point of injection as possible and then move onto something else.
I wondered if either you or T3 had experimented with intake flow straighteners, like a radius lip or a short tapered trumpet/velocity stack on the intake.

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The filter has that built in.
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snowfish
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Basic GearHead

Quote:
 
The filter housing has that built in.

^o)
Fiddling with the air cleaner is more about fun factor and sound. :D Possibly a smidgen, or a scoch, which is slightly more than a frog hair, more performance at wide open throttle. :hmm Doubtful. :shake

Our Metros had a Factory cold air intake, before cold air intakes were cool. B-) Keep it stock for best fuel economy and quietness. :drivin
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jonathan180iq
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Not Really All That Smart

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check it
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