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-   -   warm air intake mod ('98 Civic HX) (https://ecomodder.com/forum/showthread.php/warm-air-intake-mod-98-civic-hx-8784.html)

LeanBurninating 06-15-2009 03:11 AM

warm air intake mod ('98 Civic HX)
 
Sup guys.

Ive been running a PVC pipe intake for a while now, and im getting ready to swap it out for one that will soak up more heat. Im having trouble staying in lean burn mode, and this is likely one of the culprits.

So far, Ive had a friend of mine at his muffler shop take a bit of steel 2.5" exhaust tubing and crush bend it to make a good pipe that will work well. We pressed out the irregularities that the crushing caused as best we could. It doesn't look like a nice mandrel bent piece but it does look decent. The size and bend should be perfect.

I was just going to do only this, but then an idea came to me. I have been doing a bit of part time helping out at this performance shop for diesel pickups. One of the popular mods is called a heater grid delete. Check it out.

http://trivalleyperformance.com/imag..._vs_delete.jpg

They remove this heater grid for a more free flowing setup. The result is a bunch of used factory heater grids sitting around at the shop. Yes!!!

Im going to look into it more and see how much one of these used factory units will cost, how well I can fit it in, and how hot this thing really gets. My intake requires some rubber fittings and stuff, I just want to make sure Im not gonna melt anything.

Im sure it probably runs on +12 dc volts, but I don't know if I need to put a fuse in line or?? Will I be wiring it right up to the battery? Is it possible to rig it up for variable intensity? I guess we'll find out.

If it works out I would like to have it on a toggle switch next to my e brake.

What do you think?

LeanBurninating 06-18-2009 02:10 AM

88 views and no responses? Hmm... maybe you people are starting to pick up on how many projects I like to talk about vs how many I actually go through with and get done. :o

Well I really should be getting this done very soon.

I had some good convo with the diesel guys today. I thought this header grid ran continuously, but in reality its only on start up, and on a big truck with two full size batteries it sucks out enough current to make it harder to start and dim the lights and everything. Apparently those batteries will drop from 12v to 9v when that heater grid lights. So for me and my one little battery this would not work well.

As an alternative, one guy suggested I use an $8 glow plug, since its cheap, its simple to hook up and integrate, and it makes lots of heat. Only drawback is that if it runs long enough, I've been told that it will get hot enough to melt itself after about 12 minutes.

I really like this idea because it allows me to run a (theoretically) very effective warm air intake, and also toggle it off for a regular intake. Ideally I would like to have two functions:
1) some heavy duty heating power, like one or two of these glow plugs that I can turn on for cold starting that will heat up to 1500 deg. F for the aforementioned ~12 mins, this working to get the car into closed loop faster, and then in addition to these I would like
2) some type of glow plug / heating device that I can run continuously while I drive. I thought about maybe making a hot coolant line wrap around the intake pipe, but I'd rather have something electronic that I can click on and off. Plus toggle switches are where its at. yo.

Some kind of continuous heating device... a glow plug that wont melt itself that I can run non stop. Warm enough to make a difference, but not hot enough to start melting stuff lol. Any takers??????

Keep in mind that whatever I use will be mounted into a steel exhaust pipe, so it will be heating the air passing by inside the pipe, but also heating up the pipe itself, then heat soaking the air even further.



I need your brain powa!!!!

Thanks for reading.

dcb 06-18-2009 04:29 AM

using electric power, from the alternator, to make heat, in a car? Don't know what to say. :)

What was wrong with collecting air from around the exhaust manifold?
http://ecomodder.com/forum/showthrea...html#post75421

Daox 06-18-2009 08:28 AM

Ditto. You're trying to use more power to gain efficiency... Why not use wasted power (exhaust heat)? The gains are guaranteed to be better.

stevey_frac 06-18-2009 06:17 PM

If you really want to get hot air, can't you put a heat exchanger on the exhaust, and let the intake air flow over it before it enters the engine? at low load, i bet that would be very effective.

-Steve

Christ 06-18-2009 07:02 PM

You could put a heater core in the intake box (if you still have a stock intake) and run tap lines from your original heater core into it. The control would be as simple as a cut-valve on a cable from any older car... (88-91 Honda Civic for sure has them) or you could make a simple flap in your air box that would still allow cooler air to bypass the heater core, so you can somewhat accurately control temperature.

LeanBurninating 06-18-2009 10:44 PM

Thank you, oh voices of reason.

Unfortunately, none of these options include toggle switches. That just won't do.:D:D

Im using a modified intake with a cone filter, and I do agree that the best option is using exhaust heat...

However, first of all I can't switch it on or off like I can a glow plug. Also, I want to keep a short ram intake design, I want to avoid the power losses that come from snaking an intake hose all around the engine bay. The way I have it now its almost a straight shot.

A heater core would work well although I fear it is too restrictive on the air flow, and also a bit more troublesome to adapt to an intake pipe than just drilling a hole in the side to insert a plug.

Christ 06-18-2009 10:49 PM

A small heater core should almost fit directly into your intake's filter box (provided you use the original filter element). It also won't restrict enough airflow to make a difference, unless you drive at somewhat high RPM's on a regular basis... however, with the "fresh air" flap, you could easily get colder air and better flow for "performance" driving, as it were.

Just an idea though, and not fully thought out, by any means.

bgd73 06-18-2009 10:54 PM

that is a good idea..although, if late model enough, is there a means to hack maf sensor or other thermal sensor? could be as simple as finding on the intake to wrap to stay warm..or wherever it is.

LeanBurninating 06-19-2009 12:08 PM

Quote:

Originally Posted by bgd73 (Post 110740)
that is a good idea..although, if late model enough, is there a means to hack maf sensor or other thermal sensor? could be as simple as finding on the intake to wrap to stay warm..or wherever it is.

Im sure there is a way to fool the sensors, and I don't know all the intricacies of how lean burn works, but I am pretty sure that lean burn engages only when it does because its safe to do so.

In other words if you fool the sensors into putting the motor into lean burn mode when it normally would not, you could be damaging things.

DonR 06-19-2009 12:12 PM

Tee a heat riser pipe from exhaust manifold heat shield, or from behind the radiator into the intake infront of the filter. A butterfly valve on either the hot or cold side can be used to control temps. Carbed cars used a bi-metal thermostat controled, vaccum operated valve. But if you want you can use a TOGGLE SWITCH to control an electric solenoid to open & control the valve.
You could use the exhaust heat as the continuous heat & the electric heater for instaneous heat.

jonathan150cc 06-20-2009 11:22 PM

Why not just somehow type into the heat off of the exhaust manifold?
My Saab 900 had a factory setup that did exactly this. You can simply duct your air filter housing to an area near the exhaust header with some dryer exhaust tubing. :)

max_frontal_area 06-21-2009 04:53 AM

what is the purpose????????
 
why are you preheating your intake air, is the AT 30f below?

stevey_frac 06-21-2009 10:49 AM

Quote:

Originally Posted by max_frontal_area (Post 111197)
why are you preheating your intake air, is the AT 30f below?

Hot air does two things: It lowers the density of air, meaning you have to have your throttle more open to to get the same mass of air, which reduces pumping losses.

It also increases the temperatures of the air going in. Now i know that's obvious, but it's important. Most thermodynamic cycles improve efficiency at higher temperatures.

Wonderboy 06-21-2009 11:23 AM

Quote:

Im using a modified intake with a cone filter, and I do agree that the best option is using exhaust heat...

However, first of all I can't switch it on or off like I can a glow plug. Also, I want to keep a short ram intake design, I want to avoid the power losses that come from snaking an intake hose all around the engine bay. The way I have it now its almost a straight shot.
Isn't the point to sacrifice power for efficiency? I have an extra hose made of heating duct extending from my stock intake filter box to the exhaust manifold. intake air temperature rarely eclipses 150F, and normally sticks around 130F. I blocked off the stock pipe that comes from the bottom of the filter box with a plastic bag. This plus my aero mods (skirts, grille block, mirror delete) saw an 8 - 10mpg increase. I haven't done an A-B-A test yet, but I think it may have worked. I really think you should stick with the stock intake and the MAF sensor... I'd wager to guess your lean burn isn't working as much as you'd like as a result of the absence of the stock intake setup. Just pipe it to breathe right off your exhaust manifold and see what happens. You don't have anything to lose with how easy it is to try.

LeanBurninating 06-22-2009 01:47 AM

Current intake setup:

http://i42.tinypic.com/a2rihs.jpg

I like it this way versus stock because I am sure it flows easier and there are no big sound boxes. I just put this one on tonight, Im going to see if my numbers changed from the one that I swapped out (basically the same thing, except all pvc, no metal, and smaller inside diameter) and sooner or later I will try the stock intake again.

I will also cap off those air ducts from the bumper towards the filter, nice call wonderboy.

On a side note, do you think it will make much difference to relocate the breather hose and temp sensor? Will putting them further upstream yield less turbulence at the tb?

LeanBurninating 06-22-2009 02:02 AM

I am thinking that a glow plug will make too much heat, and I just know that Im accidentally going to leave it switched to "on" and just melt everything.

I know you are all not fans of using electricity for heat, but can you at least help me brainstorm here?

What about a cigarette lighter element(s) ? Enough heat? too much current? thoughts?

I mostly want to avoid anything melting off and flying into the engine....

Thanks people.

dcb 06-22-2009 06:34 AM

A few people have tried after market filters, they didn't help mpg
Testing a 'performance' air filter for MPG - Part 2 - MetroMPG.com

I do think using EXHAUST heat to offset throttle losses has possibilities , consider:
# At 0 °C and 100 kPa, dry air has a density of 1.2754 kg/m3.
# At 100 °C and 100 kPa, dry air has a density of 0.9336 kg/m3.

Not that all cars like hot air (possibly a software issue), but if yours does then if you can swing the temperature (about 100 degrees C just for example) as needed then you can basically "detune" the engine. Ok, so what you say.

Well the effects are compounding here. Your (gasoline) engine is least efficient with the throttle closed, if you are on the hiway and you are not quite at bsfc peak because of insufficient load for the engine, if you add heat, then:

1. the air going across the throttle plate and through the engine becomes less dense, therefore less restriction (1/4 less restriction in the example figures).

2. Because there is less air mass moving through the engine, you can (perhaps should) open the throttle more, reducing losses further for a given power output.

Now I have not thought enough about it to see if it affects peak bsfc rpm in a general manner, assuming an ideal ECU.

But as far as electric for heat, and why it is a bad idea, do the math, Here is your homework assignment:
1. Determine the mass flow of air you want to heat up (say, cruising the hiway)
2. Determine how much you want to heat the air
3. Determine how much power (amps*volts) you need to heat the air the desired amount.
4. Multiply that power by alternator/belt losses to determine how much power you are taking from the crankshaft (when exhaust heet is "free").

dcb 06-22-2009 07:08 AM

(another approach)
lets say you have a 2 liter engine, cruising at 2000 rpm. Lets also say the throttle is not very open for a %30 Volumetric efficiency. And you want to raise the air temperature 50C degrees.

So your engine is trying to move 1000 liters per minute, but the throttle is limiting it to 300 liters per minute.

Lets say a litre of air is 1.2g/L, so you are trying to raise 360 grams by 50C, every minute, which requires 18000 calories (not kilocalories).

Lets say (after some more googling) that a calorie = 3.08596003 foot pounds (yay), so we need 55547 foot pounds per minute worth, or 926 foot pounds per second.

Well, a horsepower is 550 foot pounds per second, so this heater requires 1.7 hp for input, so if your alternator is (swag) %85 efficient, you will be taking about 2 HP from the crank to run this heater.

A general rule of thumb is that your (not huge) car only needs about 10-15 hp to maintain speed on the hiway, so 2hp is a very large chunk of power just to run a heater (when exhaust heat is free). You will need to draw almost 100 amps for this example.

Wonderboy 06-22-2009 07:19 AM

Holy ****, dcb. That sounded like a heaping dose of reason. Impressive. I'd probably halt my electric air heater project right there, LeanBurninating. He's made of reason. Another theory I have (may or may not be true) is that the ECU is looking for some very specific parameters, one of which HAS to include MAP (Manifold Air Pressure). By "increasing" the flow with a cone filter, you are lowering the very specific pressure parameters the ECU expects, and may also be a reason you don't get lean burn as much as you want. If there's someone who knows the real answer to this, please shed the light!

dcb 06-22-2009 12:23 PM

I screwed up, by a factor of 2. A 2 litre engine at 2000 rpm will try and move 2000 literes per minute, not 1000 litres. So you are looking at 4 crank hp for a heater to affect that airflow by 50C degrees.

LeanBurninating 06-22-2009 12:27 PM

ok ok ok ok.

You make a good argument, although you assume it will be run continuously, and you do not account for the decreased amount of time spent out of closed loop on cold start, as well as time spent in and out of lean burn.

It also happens that using exhaust heat requires the length of the intake tract outside of the tb to almost double. Isnt that a considerable amount of restriction?

Daox 06-22-2009 12:30 PM

Not if you use a larger diameter pipe.

Also, longer intake pipes usually increase low rpm torque, which is also good for mileage. So, you get a win win.

LeanBurninating 06-22-2009 12:32 PM

True, but at some point you have to neck down the pipe to the size of the throttle body. And from the different intake designs I have been trying, I believe any neck down near the throttle body makes too much turbulence and has a negative effect.

Daox 06-22-2009 01:09 PM

Well, yes, you want to neck down far before the throttle body. You want a smaller pipe connected to the throttle body for increased low rpm torque, and you want to adjust its length to play with the torque a bit too. But, before that, just use a large pipe. I don't see any problems with using aluminum dryer ducting like others have.

dcb 06-22-2009 01:28 PM

Quote:

Originally Posted by LeanBurninating (Post 111461)
... although you assume it will be run continuously...

I did no such thing, sheesh. If you want to run the thing it will cost you 4hp while it is running, is that better?

Quote:

Originally Posted by LeanBurninating (Post 111461)
and you do not account for the decreased amount of time spent out of closed loop on cold start, as well as time spent in and out of lean burn.

I suppose if you want to argue that doing a long smokey burnout coming out of your driveway also shortens "out of closed loop" time, for a net efficiency gain then I would like to see that bit of figuring too :)

Seriously, 4hp is a huge deficit to overcome in efficiency terms.

Southcross 06-22-2009 02:28 PM

Quote:

Originally Posted by dcb (Post 110567)
What was wrong with collecting air from around the exhaust manifold?
http://ecomodder.com/forum/showthrea...html#post75421

that is how VW has been doing since the beginning of time...

sadly most of us have been removing them from our cars... they either have rusted out or have broken.... I'm one of the few trying to find the parts to re-install it into my car LOL

Christ 06-22-2009 03:15 PM

Your new intake doesn't really pose any less restriction than the OEM one did, as long as you're operating at low-throttle angles and less than 3000 RPM.

If you want to test that, find the max flow of the old OEM intake system with the most restrictive filter on the market. (This will give you a better chance of being right).

Then, make a graph which compares actual airflow of the engine (assuming 100% efficiency) with engine speed and throttle angle (3d graphing).

And find the plot points that line up with the OEM filter/intake's flow capacity.
Now, test the "new" intake that you've made. I bet you'll find that they pretty much align on the same plots until you get over 70% throttle, or over 3000 RPM.

You can build a simple box around your exhaust manifold using the OEM heat shields that will pipe hot air over to the filter without fully enclosing it. If you want the filter at the end of the intake pipe, the filter is normally the place with the greatest turbulence in the intake tract, not counting the throttle plate and places in the intake manifold/plenum, so if you're going to step down, that's the place to do it.

Any bend in your intake tract should (be larger diameter than the straight sections) allow for expansion due to pressure drop on deceleration of flow, while keeping flow attached at the outer walls of the intake piping for the best torque curve available from the design choice.

If you're using 4HP on a 30% duty cycle (You're using the heater 30% of the time and using residual heat the other 70%) and 10 HP to move your car at a steady speed, you're now using an average of 10*1+(4*(3/10)))/2 to maintain your speed and current intake temp.

The formula works out to 11.2 HP.

What this means is that you're using 10+ percent more HP now to maintain that speed and intake temp than you would be using if you didn't have the heater in the intake tract.

This means that you have to overcome another 1.2 HP loss before you make up for pumping losses. The extra load on the engine produces (marginally) more heat in the exhaust, which again is just wasted energy.

This isn't taking into account the closed loop operation or extra time spent in lean burn mode, this is actually assuming a basic engine driven at a given speed for a given output.

The formulae to convert units to account for the potential of leanburn operation and closed vs open loop mode would probably just make us all annoyed.

max_frontal_area 06-24-2009 05:06 AM

Quote:

Originally Posted by stevey_frac (Post 111222)
Hot air does two things: It lowers the density of air, meaning you have to have your throttle more open to to get the same mass of air, which reduces pumping losses.

It also increases the temperatures of the air going in. Now i know that's obvious, but it's important. Most thermodynamic cycles improve efficiency at higher temperatures.

the more air molecules your induction sys can pump into your filling cylinders
the more power you will make per cycle. you can do so by augmenting airflow
with an optimized air intake tract, ram air or some kind of supercharging. or by chilling your intake air. more air molecules even cooler ones than ambient will be compressed and heated during the compression stroke in a gasser but more pronounced in a autoignition cycle. hotter air burns more readily as rudolf diesel found out almost 100 years ago. that in turn allows you to make more power with fewer rpms, think artificially turning a 4 cyl into v8!
lower rpms --> easier to fill cylinders, and empty them reduced reciprocating and parasitic forces, less frictional related heating (on moving/rubbing sliding parts) additional time for more complete burn... i can keep going.

why not utilize a fourbanger as a V8 and enjoy more power, economy and longevity instead of crippling it and forcing it to perform as a twin?!

heat your fuel like smokey did. he got an 80's chevy to give him 100 mpg?
just be careful if gas is your choice of fuel!

micondie 06-24-2009 08:38 AM

intake tuning
 
Quote:

Originally Posted by Daox (Post 111481)
Well, yes, you want to neck down far before the throttle body. You want a smaller pipe connected to the throttle body for increased low rpm torque, and you want to adjust its length to play with the torque a bit too. But, before that, just use a large pipe. I don't see any problems with using aluminum dryer ducting like others have.

As an old hot rodder it has always been my understanding the only part of the intake that has much effect on power and torque is the length and diameter between the intake valve and the plenum where all the ports merge. (Has anyone seen the old long ram intake that Chrysler put on their performance cars in the mid 60's. They had very long individual ports that crossed the motor and joined in plenums over each rocker cover where the carbureters were mounted) That length could be altered on a motor with a two piece intake by putting a spacer between them. The distance from the plenum to the throttle body might have a very small effect. Beyond that point your only goal is to reduce restrictions to maximize air flow. I don't think that putting some baffles around the intake manifolds to direct warm air to the air cleaner would increase air flow restrictions because the surface area of the manifolds and therefore ths size of the baffles would be much larger than the area of your air cleaner intake.
I am curious if anyone has taken air flow reading comparisons of the air flow restrictions of different size throttle bodys at low lthrottle openings?

Daox 06-24-2009 08:45 AM

Intake manifold design does have a larger effect on torque, but intake diameter and length can still play a significant role. Check out the article below.

AutoSpeed - Pipe Dreams

stevey_frac 06-24-2009 08:59 AM

Quote:

Originally Posted by max_frontal_area (Post 111852)
the more air molecules your induction sys can pump into your filling cylinders
the more power you will make per cycle. you can do so by augmenting airflow
with an optimized air intake tract, ram air or some kind of supercharging. or by chilling your intake air. more air molecules even cooler ones than ambient will be compressed and heated during the compression stroke in a gasser but more pronounced in a autoignition cycle. hotter air burns more readily as rudolf diesel found out almost 100 years ago. that in turn allows you to make more power with fewer rpms, think artificially turning a 4 cyl into v8!
lower rpms --> easier to fill cylinders, and empty them reduced reciprocating and parasitic forces, less frictional related heating (on moving/rubbing sliding parts) additional time for more complete burn... i can keep going.

why not utilize a fourbanger as a V8 and enjoy more power, economy and longevity instead of crippling it and forcing it to perform as a twin?!

heat your fuel like smokey did. he got an 80's chevy to give him 100 mpg?
just be careful if gas is your choice of fuel!

You suggest that lower RPM translates to easier to fill cylinders. This is true to a point. Modern cars have over laping cams. The intake valve remains open until slightly after the intake stroke finishes. At the right RPM, which translates to the torque peak of the engine, the air in the intake tract has a lot of momentum as it is pulled into the engine, and continues to fill the cylinder as the piston comes back up for the compression stroke.

In engine terms, we refer to how 'full' we get the cylinders as 'volumetric efficiency'. A volumetric efficiency of 100% would mean that you were able to fill the cylinder completely with ambient air pressure. Some cars are able to achieve slightly higher then 100% volumetric efficiency without a supercharger!

As for using a 4 banger as a v8. You lost me. Unless you are suggesting turning your car into a 2 stroke? In which case, you will enjoy increased power at the expense of engine longevity, fuel economy, and emissions. I doubt anyone could make a 2 stroke engine pass modern emissions requirements.

Heating the fuel works great. If your using veggie oil as fuel anyways. Gasoline dosen't have any difficulty vaporizing. Even regular diesel does fine. I've never seen any indication that heating fuel has any significant impact on fuel consumption with good fuel. An otto cycle gasoline motor made of steel is limited to about 37% efficiency. So i doubt smokey got 100 MPG on a car that the EPA rated at 25 without aeromodding the crap out of it.

micondie 06-24-2009 09:07 AM

Thanks, That is very interesting. I learned something new. I would guess that this was the result of the reduced restrictions in the fuel injection compared to the old carbureters. I did note that the power gains came mostly over about 2400 RPM and I assume were at large throttle openings. Below 2400, where most driving is done, there was a reduction in power.

stevey_frac 06-24-2009 09:11 AM

Quote:

Originally Posted by micondie (Post 111862)
As an old hot rodder it has always been my understanding the only part of the intake that has much effect on power and torque is the length and diameter between the intake valve and the plenum where all the ports merge.

I had to design an intake system for a formula SAE competition car and the intake primary runner length, and diameter are the most significant parameters, So long as the rest of your intake doesn't have any major restrictions. The intake low pressure pules are generated at the valve, and end up reflecting off the end of the open intake runner. At the right frequency a high pressure ridge is sitting at the valve as it opens, and presto! More torque.

If the intake runner is to large (diameter), it dosen't build any momentum, and volumetric efficiency is low until a higher RPM. If the intake runner is short, this also favors a higher RPM set point. Ideally, you design your cam, and your intake runners to give you a broad range of favorable operating conditions.

Back on to the topic at hand, the warm-air intake. It's something i'd love to try, but I lack the intestinal fortitude to try it! My intake air temp is always close to ambient.

max_frontal_area 11-25-2009 01:51 AM

Quote:

Originally Posted by LeanBurninating (Post 111381)
flows easier

you could save some weight as well by switching out that piece of exhaust
pipe and substituting it with a drinking straw :eek:

max_frontal_area 11-26-2009 02:48 AM

Quote:

Originally Posted by stevey_frac (Post 111870)
You suggest that lower RPM translates to easier to fill cylinders. This is true to a point. Modern cars have over laping cams. The intake valve remains open until slightly after the intake stroke finishes. At the right RPM, which translates to the torque peak of the engine, the air in the intake tract has a lot of momentum as it is pulled into the engine, and continues to fill the cylinder as the piston comes back up for the compression stroke.

In engine terms, we refer to how 'full' we get the cylinders as 'volumetric efficiency'. A volumetric efficiency of 100% would mean that you were able to fill the cylinder completely with ambient air pressure. Some cars are able to achieve slightly higher then 100% volumetric efficiency without a supercharger!

As for using a 4 banger as a v8. You lost me. Unless you are suggesting turning your car into a 2 stroke? In which case, you will enjoy increased power at the expense of engine longevity, fuel economy, and emissions. I doubt anyone could make a 2 stroke engine pass modern emissions requirements.

Heating the fuel works great. If your using veggie oil as fuel anyways. Gasoline dosen't have any difficulty vaporizing. Even regular diesel does fine. I've never seen any indication that heating fuel has any significant impact on fuel consumption with good fuel. An otto cycle gasoline motor made of steel is limited to about 37% efficiency. So i doubt smokey got 100 MPG on a car that the EPA rated at 25 without aeromodding the crap out of it.

'volumetric efficiency' is my user name on some other forums - i am well aware of the term and its implications.

originally written by me:
why not utilize a fourbanger as a V8 and enjoy more power, economy and longevity instead of crippling it and forcing it to perform as a twin?!

allow me to translate. a large 4 cylinder coupled to an carefully designed efficient turobocharger system (not just the blower but intercooler, a misting system for keeping a heat soaked IC cool, and perhaps even water injection)
will provide you with fantastic economy if driven responsibly but can also
pull like a big engine. as long as you dont go cheap on turbo sizing like most manufacturers do. visit europe if you have the means. lots o lil highstrung engines with turbos. halvofem are diesels.
that explains the "fourbanger as a V8" now i will move on to "forcing it to perform as a twin".
now you take that same fourbanger and instead of feeding it the most and coolest air then splash in fuel to get your stoicio on - or even a lil less for lean burn because you have gone to great lenghts to feed it COOL air you have a margin or error in melting your engine. the result, your engine has to perfom fewer cycles. your have great economy, possibly awesome, and an engine that is maximized (in terms of efficiency and power combined)
add a spritz of water and you can take lean burn to new heights.
eat your heart out honda!
derailed myself again back to my point.
that same 4 be it a V, L, boxer or what have you, now you do the exact opposite of above. now you cleverly cheat it out of the air molecules that it wants so badly to do its job of pulling you down the road. add insult to injury to do all this at the point of risking hurting your engine - in the name of airflow. Heil!

Smokey Yunick, holder of various patents - author of a few books.
yes indeed and in an 80's chevy!!, and no, by heating his fuel only (gasoline)
he provided one of very few brains during the good ol days of good ol boy racing.

when you get your IT preheating worked out be sure to send this guy an email and fill him in on why he failed reaching his 300 MPH goal.
it is the all red firebird, i suggest you do some research on it to see what you can do when you chill your intake air.

max_frontal_area 11-26-2009 02:52 AM

here is the link:
 
Banks Power | Twin-Turbo Revival: Part 1

Christ 11-26-2009 10:43 PM

I have to mention that if your engine is functioning, and not malfunctioning, you're not depriving it of airflow. Keep in mind that most engines are already running air deficient compared to their max VE. By using hotter air, you're only allowing a higher throttle opening without making unnecessary power, reducing pumping losses. You're not putting your engine in danger at all, other than from detonation, and if your engine didn't like the warmer air, you'd be getting worse mileage as it dumped fuel to keep detonation at bay, or retarded the timing for the same reason.

None of the reasons in your post, although they were posted with conviction, as it appears, weren't "the whole story" as it were.

Lots of cars could benefit from a smaller engine with a turbo, because you're not really efficient at low throttle angles, and an engine that's small enough to be truly efficient at cruise conditions isn't going to be able to accelerate quickly enough to really be effective in the real world. Add a turbo and a bit more fuel with detonation deterrents to that smaller "efficient cruise" engine, and you've got a great combo.

Hm. I didn't go to engineering school, and automakers still haven't really figured this out.

max_frontal_area 11-27-2009 02:17 AM

Quote:

Originally Posted by Christ (Post 141825)
I have to mention that if your engine is functioning, and not malfunctioning, you're not depriving it of airflow. Keep in mind that most engines are already running air deficient compared to their max VE. By using hotter air, you're only allowing a higher throttle opening without making unnecessary power, reducing pumping losses. You're not putting your engine in danger at all, other than from detonation, and if your engine didn't like the warmer air, you'd be getting worse mileage as it dumped fuel to keep detonation at bay, or retarded the timing for the same reason.

christ. have you ever tried/had to attempt to fix or even seen the internals of an engine that expired from detonation? google up some images
from street engines. then look at racing. high boost turbos, AA blowers, nitrous coming on without the additional fuel needed appropriately responding.
have you ever seen sparkplugs that look as if they had been made by alcoa?

"You're not putting your engine in danger at all, other than from detonation, and if your engine didn't like the warmer air, you'd be getting worse mileage as it dumped fuel to keep detonation at bay, or retarded the timing for the same reason."

you are obviously talking about an FE engine.
modern FE engines are equipped with dual band knock sensors which will knock back timing (i cant believe i said that :) do that long enough and your
exhaust manifolds will begin to glow and with the *concept* of wanting to flow preheated air through them there is even less capacity for cooling.
if that/those manifolds are made of aluminun they will be at risk of melting. now imagine having a dummy car with only a carburetor and mechanical distributor and no way to sense less than ideal combustion and the only way for you to find out through the coolant gauge, steam emitting from the hood.

there are ppl on here that dont know how to bump-start a coasting car
and they are being counseled to draw their intake air out from under the
exhaust manifold shield? UMBFK!

Quote:

None of the reasons in your post, although they were posted with conviction, as it appears, weren't "the whole story" as it were.
the story from my contingent is complete.
now i would like to hear yours.
please dont repeat: "higher throttle opening without making unnecessary power, reducing pumping losses" as i have read it many times. it is a simple
concept, not difficult to understand- thin air is favored when flowing around
objects, tight radii, sharp valves and seats, throttle plates and even carburetor internals found in older vehicles.
the concept i cannot warm up to no matter how hard i try,
is how an engine that is ingesting fewer air molecules can produce more power per cycle than the same engine being fed more.

Quote:

ots of cars could benefit from a smaller engine with a turbo, because you're not really efficient at low throttle angles, and an engine that's small enough to be truly efficient at cruise conditions isn't going to be able to accelerate quickly enough to really be effective in the real world.
Add a turbo and a bit more fuel with detonation deterrents to that smaller "efficient cruise" engine, and you've got a great combo.
Quote:

Hm. I didn't go to engineering school, and automakers still haven't really figured this out.
"an engine that's small enough to be truly efficient at cruise conditions isn't going to be able to accelerate quickly enough to really be effective in the real world"

sequential turbocharging, electrically assisted turbos, variable valves, momentary ultra lean burn, and most recently VWs upercharger/turbocharger technology have most been implemented in OE situations, as well as availability for the aftermarket
(except for VWs s/t technology)
once again i would encourage anyone with the means to visit Europe.

Christ 11-27-2009 02:30 AM

Yep, seen plenty of engines that "expired" from detonation.

Why are you talking about racing engines on a forum dedicated to fuel efficiency? I'm not really into humoring it, but noone has ever said (to my recollection) that you get more power per cycle with warmer air. The reduced pumping losses make the engine more EFFICIENT, not more powerful. Reduced pumping losses, to an extent, also account for a large percentage of the power lost due to the thinner air taken in.

So you're out for maximum power in any situation? Try tuning for WOT. Sure, at WOT, colder air is much better for making power (not always, but yeah...), but during the normal drive cycle, how many times are you using the engine's full potential? I mean, honestly - do you rev your gasser to 6k and shift from every red light? If you do, methinks you're on the wrong forum, bud.

The idea is a breakdown of efficiency per volume. Since we all know it takes power to make power, and power is always lost in the conversion, and it always takes the same amount of power to do the same amount of work, the only real variable is the amount of energy that is lost converting the source to the motive force, which are frictional and pumping losses (among others). The idea is to use what you have more efficiently, not create more of something you already have an excess of.

The most efficient setup would leave the operator able to operate at WOT and maintain a steady speed/power output. That would be a diesel engine, in most cases, although throttle-less gas engines are apparently also in production now.

In the case of gassers, there is always the option to make a variable intake system, and it's not even that difficult. The average DIY'er can do it with a few hours' labor and some salvage parts. When this is the case, the variable intake temp can lead to the availability of excess power as well as higher efficiency, simply by changing the intake flow temperature to suit your needs.

So again, what's so hard to understand about using warmer air? I'm afraid I don't see where the cold air argument is relevant to our goals here at EcoModder?


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