The intake is not a weak link in the system for the stock motor. It's not like the restrictive intake boxes of the 90's Hondas with the tiny intake tubing.

 

I always got less mpg in LA than out back of SD but it was because tghe stop and go traffic in LA effectively squashed my mg. Dioes that happen to you?

 

What can I clarify for you? That was typed in a bit of a hurry.

 

This is effectively what I was saying.

In fact depending on the change in diameter/number of bends and pick up location you can lose a considerable bit of torque as well.

All depends on what has happened to charge velocity.

 

let's put it this way in an analogy.

The regular intake already provides enough air in this car. It isn't the bottleneck.

It would be like you saying for an average Human i can't breathe at altitude because my teeth are in the way, so should knock out my teeth or cut my cheeks off into a joker smile to get more oxygen to my lungs.

 

OK, we know that horsepower is lost at 3% per 1000ft in altitude. If Honda is allowing me to feel this gain going to sea level (denser air), then why would it be a waste of money to increase flow? I understand it would be the same density but we also know the more in and out makes power whether through RPMs or displacement.

Does the ECU provide a limiting factor? The VQ Nissan pulled the throttle plate to less than 100% basically limiting any gain in flow from an intake.

Technosquare removed this limitation through programming.

"Throughout our testing we found, the drive by wire system was programed to never fully open. In fact, it actually closes the closer you get to the rev limiter, by as much as 20%."

My question is does Honda do this?

 

because intake does not increase volume of air consumed

See analogy above, does knocking out your teeth help you breath better?
You need something to compress the air to force it down your throat, not just making your mouth bigger.

 

That may be. I don't remember the traffic on the 210 being substantially worse than traffic on SLC's I-15 during rush hour.

But in LA I felt this insatisfyable desire to drive 80+ MPH when there wasn't traffic. Sure that played a role.

 

You are not gaining anything, you are just approaching stock output when you return to sea level..

Your situation is not ECU limited. The ECU can limit output, but that is not what you are experiencing.

An intake will not do you any good, and will likely rob you of yet more power under the curve.

Savvy?

 

The EDCU merely selects the output signal to injectors and to spark timing based on inputs from MAF, rpm, throttle position, atmospheric pressure, and other, mostly emissions related inputs. The ECU is programmed to cut back ignition signal when redline is reached; none I have wortked with do anything to 'retard' the engine torque per se; in fact such could be dsmaging. Nothing is done to control torque. Since torque is a function of hp, any limitations are better served by ignition than by limiting intake air. So what are yiou inferring by limiting torque? doesn't compute. RPM is limited, not torque.
What is shifting the power band to the right mean? has no meaning to those of us designing fuel inputs to engines with a computer. The airflow is matched with engine requiremednts to signal the injectors time open and close and ignition timing. No such shift happens anywhere with that 'masp'.. So what do you call a 'shift to the right' ?
Why has OP shot himself in thed foot? His answer merely is that low restrictive air filters, that is, ones with less pressure drop across the filter for any given air flow, are an advantage when rpm is greatrer than 5500 rpm and the air flow heads for the most possible from the engine but not when air flow is quite low. Air boxes are indeed a restriction if the filter itself is too small in area but thats almost 100% not the case with modern engines. A 1500 cc Fit engine turning 6500 rpm requires theoretically about 180 cubit feet per minute of air (3 cu ft per second) so the air filter has about 1.0 sq ft of area. That means at max rpm the filter must pass about 3 cubit ft of air per second per sq ft , pretty normal and not terribkly restrctive for a filter with media designed to filter out 50 micron particles.. The way to reduce the pressure drop is by increasing the filter media area or by changing the media to a less restrictive media. The latter more often increases the micron size that the filter will pass at 10% loading meaning the filtrate has added 10% of its design loading. And of course most systems do both so as not increase the particle size that the filter will pass.. Since the observed reduction in the work the enguine must do to suckj air thru the filter is only worthwhile near the top of the rpm range expensive filters just aren't that valuable for street engines. And the risk of fouling MAF' when filters using special oils to snag dirt etc are used the probability of fouling thed MAF is increased. If you want a headache thats the way to gert it.
Just what is moving greater oxygen mass mean? Your air comes in different oixygen contents? Theres either more air or less air and the ECU has no alteration. It only measures the air being sucked in by the engine.
Just what are you defining as 'charge density?
For us its the combination of air and fuel charged to the combustion chamber and there's no measurement for that.
As for oxygen mass, I can't even guess what that is.

Clarification is awaited. Please don't try to tell me your words are different but you're saying the same thing. You're not.

 

Time out.

Horsepower is derived from Torque. Torque is a moment applied to a lever arm. Torque over time is power, in this case converted to units of "Horsepower"



Mass Flow sensors whether its called a MAF or a MAS depending on manufacturers nomenclaturr, just like Nernst cell oxygen sensors, put out a voltage based on the actual MASS of the element oxygen in the stream.

Air is composed of many elements, nitrogen for instance being the greatest proportion per unit volume, but we are concerned with the amount of oxygen available. What are you burning the fuel with, again? Thats right OXYGEN.

And Mass measurement is the only reliable way to account for it. Molecular mass for a given volume (engines are volumetric devices, or pumps) does not change as the volume is exposed to environmental factors.

This is why I can pump 85lbs/min or more through a tiny 2.0L engine at only 10k rpm. Its under pressure. Conversely, its the same reason that an NA application would lose power at altitude. Charge density has decreased.

The swept volume didnt change, the pressure at which the air was introduced did. The engine can only ingest so much volume at a given point, but we can change the density.

Why do you think injectors are typically listed in (lbs/hr) when rated on gas? When you see them listed in cc/min they are using a spec fluid on the injector test bench at a fixed temperature and increments of pressure (~43.5PSIg or 3bar is industry standard), and that spec fluid has a known specific density.

Please tell me this concept is not foreign to you, speaking of density.

Additionally, OEs do in fact calibrate for torque ask folks like Greg Banish who is a Calibrator for Ford and who's lectures I have attended.

Spark Angle Advance/Retard is directly related to cylinder pressure and BMEP, which is what will determine torque.

In no way will you cause damage by limiting torque as a fail-safe through timing retard, but you might increase your EGTs.

Please note that if those EGTs get to the point there is damage sustained.. like melted exhaust valves, burned seats or damaged turbine wheels... you have bigger problems in the tune then the spark timing.

You seriously don't understand what it means to shift the power band to the right? As viewed on a two dimensional plot (like say a dyno plot?), the quadrant of a graph around the origin (X0,Y0) where both Values of X and Y are always positive is going to be on the right hand side.

So If you made peak power on the stock setup at coordinate +X1,+Y1 and then switch to an intake that caters toward the upper end of the rev range peak power will shift up and to the right side of the plot (further away from the origin X0,Y0) towards +X2,+Y2..

Before you criticize my post you may want to go back to the basics.

Also try some simple formatting and sentence breaks, that block of text is damn near unintelligible.

As for your closing statement.. the handy thing about the english language is that you can describe the same concept in multiple ways.

FYI a "cubit" and the term "cubic" are two entirely different items if we are going to play the pedantic game.

Clarification provided. I'm not even going to bother going any further with VE or the dynamics of compressible fluids if we cannot get over these little speed bumps.

 

This is why I stopped putting tech out on this forum, where even a self proclaimed master engineer and racing aficionado can f*ck up the basics so badly and not even know it.

For the longest time I held a lot of respect for you, mahout

 

That doesn't seem right. I don't think MAF directly sense oxygen, just air flow (I would call the air flux coming from a pure physics back ground, no idea what you car people would call it).

 

The exposed "hot wire" in the MAF/MAS reacts with the oxygen and puts out a voltage. There are also Vane/Karman style MAF/MAS sensors which use pulse width modulation, but they are more rare then they were early on in the EFI world. AC Delco (usually found on GMs like the LS motors) produces "cold wire" element MAFs

This exposed (often platinum) element is the part that can get fouled.

Nernst cell sensors operate on a similar concept.

This can all be easily researched. The membrane/element reads the ion charge as the molecules pass over it. This is electrochemistry.

 

No. The hot wire is cooled by the airflow, which changes its resistance, which changes the measured voltage across it. There's no reaction. If it were exposed to pure nitrogen air (i.e. inert air) it would still measure the mass flow.

edit: doesn't mean it still can't get fouled, any sort of accumulation along the surface will affect the heat flow. But regardless, there's no direct measurement of oxygen.

 

Bingo... Its a Wheatstone bridge. The platinum is used because of it's linear resistance characteristics versus a change in temperature. We use these all the time for hydrogen measurement in nuclear power.

If it did react with the oxygen, it would be consumed, requiring periodic replacement.

 

Ahh yes With respect to the Hot Wire platinum elements.. You are correct. My apologies. Those are based on resistance Good Call

I am stuck thinking about the ORM sensors I've been working with (not the temperature differential version MEMS), which similar to Nernst cells compare the potential generated in exhaust oxygen proportion to the potential registered in the atmosphere that they are to be calibrated with.

http://www.schnitzracing.com/manuals/AEMWBK.pdf

Which as noted are consumables, with regular replacement required.

Note that the Hot Wire is not the only style. There are also oscillating circuit and pulse width mod. (cold wire) MAFs, Drag-Vane MAFs, Laminar Flow MAFs Karman Vortex MAFs to name most but not all

There are also galvanic/electrolytic cells, etc.


A MAF isnt the only way to measure massflow either, there is also Speed Density based on temperature, pressure, baro and a known VE table.. and Alpha-N algorithm tuning.

The point is that oxygen mass is what is important to power production. There is no escaping that.

The amount of power a Gas Turbine, HCCI or ICE engine, whatever, can produce is dependent on how much oxygen can be put into it. Which is what I've been trying to convey all along.

 

We have answered in great detail how the ECU COULD limit engine power. Roger that, understand all.

I still don't think we have answered the OP's question:

Maybe I see his question differently. I would word it as this:

Is this particular ECU specifically programmed to limit power to an arbitrary value, say 100 FT/LBS of torque and not exceed it no matter what? In this case, modding the Fit would be worthless.

If this is not the case, then modding the fit would yield gains, even if they were minuscule to the average driver due to varied reasons such as RPM's required to see an appreciable change, other complimentary mods needed to see the full effect, etc. etc.. I am asking overall, understand some torque may be lost at the low end, etc etc. If I looked at a dyno graph, would the curve generally have moved up the Y axis?

 

I had to check on this, because platinum is generally not consumed by anything. Turns out that the platinum is not consumed in an O2 sensor, but damaged by other means:

 

From what I have seen, yes both GE/GD dial back the power.

You can get small increases out of modifications for short periods of time until the ECU gets wise after a couple of drive cycles to the added airflow from complimentary N/A VE mods.

The GE is especially tough to fool, even with a piggy back like the FIC. It can be done though.

Unless you get a Dastek, Emanage, FIC, MegaSquirt, MoTeC unit etc you are throwing money away.