Home brew intake mods

[Christ]

Originally Posted by Jyden

@ Christ - I rest my case - I belive that we are "talking" past each other - hence further writing will gets us nowhere.....

I'm with my curret abalities within English unable to get my message through to you in a manner you can understand.

Thanks for the dialoque....

Your English is fine.

[tasdrouille]

- Pre-heated intake mixture at low rotational speed improves combustion. (Chiu and Horng, 1992)
- Specific fuel consumption varies inversely proportional to the square root of the suction air temperature (Nakajima et al. 1969).
- Higher ambient temperature is found to increase the flame speed, the combustion reaction rate, the uniformity of the fuel-air mixture and reduce the heat transfer rate though the cylinder walls (Pulkrabek, 1997).

References:
Chiu, C.P., and Horng, R.F., 1992, “Effects of Intake Air Temperature and
Residual Gas Concentration on Cycle-to-Cycle Combustion Variation in a
Two-Stroke Cycle S.I. Engine Equipped with an Air – Assisted Fuel Injection
System”, JSME International Journal, Vol. 37, N.4, pp. 957-965.

Nakajima, K., Shinoda, K., and Onoda, K., 1969, “Experiments on Effects
of Atmospheric Conditions on the Performance of an Automotive Gasoline
Engine”, SAE Transactions, SAE 690166, pp. 745-766.

Pulkrabek, W.W., 1997, “Engineering Fundamentals of the Internal
Combustion Engine”, Prentice Hall, Inc.

Here's an interesting read:

Changes of Low Load Engine Parameters by Temperature of Mixture

In this research, they were able to reduce BSFC at low RPM and low load by 7% at 195 F vs 100 F. Also, indicating that density reduced throttling losses have not much to do with it, they measured almost the same throtte position at those two temperatures.

[Jyden]

Injection systems are complicated. Changing one thing will cause the ECU to change a lot of oter things.

As to undertand how theese things work - at least in some Toyota applications, this is a good read.

http://www.autoshop101.com/forms/h25.pdf

(Pls note the role of the oxygen sensor)

[Christ]

Originally Posted by Jyden

Injection systems are complicated. Changing one thing will cause the ECU to change a lot of oter things.

As to undertand how theese things work - at least in some Toyota applications, this is a good read.

http://www.autoshop101.com/forms/h25.pdf

(Pls note the role of the oxygen sensor)

Injection systems are complicated, yes. Their ultimate goal is to run the engine inside of pre-determined parameters. How they go about it is of no consequence to us, as long as the end result is the same.

[Jyden]

"How they go about it is of no consequence to us, as long as the end result is the same."

Funny enough I find the "how they go about it" at the outmost importance, especially if I want to tinker with things - if you don't understand how things work from the start on - how will you sucessfully improve them ???

[Christ]

It doesn't matter how the injection system works if the end result is the same. The end result, in this case, is a control system that monitors and controls AFR based on predetermined programming. Since you're attempting to discuss engine efficiency based on intake temperature, the injection system is only relevant insofar as determining that the ECM will compensate with increased or reduced fuel to maintain a predetermined AFR.

You're not trying to improve the injection system by adding a HAI/CAI to the engine.

[tasdrouille]

Originally Posted by Jyden

Injection systems are complicated. Changing one thing will cause the ECU to change a lot of oter things.

As to undertand how theese things work - at least in some Toyota applications, this is a good read.

http://www.autoshop101.com/forms/h25.pdf

(Pls note the role of the oxygen sensor)

And your point being? So far all I have seen is your understanding of how things work. What I would like to see is actual research supporting your conclusions, which you have yet to provide.

Whatever your argument is, don't tell us why it's that way, show us why based on the work other people have done in research labs.

[White118]

So........ maybe I will check back in a few days when you guys have figured out what is best. NOW FIGHT TO THE DEATH!!!! LOL

[Christ]

Originally Posted by White118

So........ maybe I will check back in a few days when you guys have figured out what is best. NOW FIGHT TO THE DEATH!!!! LOL

This fight is about the equivalent of a Pit Bull and a stuffed animal right now. There have been much worse...

Unfortunately, the issue here isn't being acknowledged at all, and that is whether or not the engine's dynamics are altered by the introduction of warmer or colder air, and whether those potential changes are positive/negative, to an FE stand point.

We already know that, all things equal, the approximate power output and throttle angle will be the same, and nearly the same amount of fuel will be used to create that power figure. The change at WOT between HAI and CAI is no more than 10HP max (5HP where we drive) on even mid-high powered engines. It will be much smaller on a G10.

Of course, you've seen the suggestions, and neither mod is very difficult, so why not just try it out and report back with your testing/conclusions?

[Jyden]

I will one last time try to explain it:

Our goal is to maintain a certain speed with the least possible use of Hp / Kwh / fuel. Right ?

The ECU constantly reads engine temp, air temp / mass, throttel position / vaccum, and oxygen level in the mix.

Now - let say, that you for going 50 mph have to take the throttle to position 20 out of for instance 60...

Now you lower the air intake temp with 40 degrees centigrade, thus adding 8 - 12% more oxygen to the mix.

What will happen?

Will the car accelerate? Decellerate? Maintain speed?

The car will accelerate, because the oxygen sensor reads a higher level of oxygen, it will add some more fuel and the car will accelerate.

To maintain speed you let go a bit on the accelerator....

What we in essence have achived with the higher level of oxygen in the colder intake air, is an improvement in engine effensicy, so that it now develops some extra kw at the wheels at a given rpm. This could also have been done by using a more energy rich fuel, but that costs....

If you don't belive me, try to add some NOX instead of the extra oxygen. You will soon be caught for speeding....

Essentially what we talk about is that the car has to over come a certain resistance to get to a certain speed.

If you lower drag you can go at the same speed with less throttle, if you lower rolling resistance in tires you can go at the same speed with less throttle, and if make the engine more effecient you can maintain same speed with less fuel.

Now there are some traps in this, as the oxygen sensor and ECU will try to adapt the mix to optimise the - for emmisions - best working temp for the catalyst converter - thus to some degree changing the above.

OK - if I'm wrong - pls tell me why - not just that I'm.