warm air intake mod ('98 Civic HX)

[123456]

Originally Posted by LeanBurninating

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.



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?

always fuse electrical circuits, its a safety must or you might be cooking marshmallows with your entire car.

[Wonderboy]

What?

[Christ]

The grid heater is designed to bring the air temperature up during cold starts for diesel engines. You probably knew that.

The problem is that it's a resistive element heater, and is going to draw ALOT of juice from your electrical system. It's almost never going to be profitable to introduce another waste stream into your engine's systems to gain any kind of efficiency, because it will be a net loss.

Frankly, unless you need cold start assistance (not likely unless you have serious engine problems) I wouldn't really bother.

[beer]

I agree that a warm intake could help with better MPG, BUT not with lean-burn honda engines!
With these engines you want to stay as much as possible in de lean-burn mode, and the ecu gives the leanburn signal according to engine sensor parameters, one off these is the TPS-sensor (Throttle Position Sensor), which the ecu sees has a signal how much load you give it. (TPS 32%)
Has you know the leanburn mode works only with light load .
With a warm intake you give more throttle, thus give a higher TPS signal, which will deactivate the lean-burn mode.
So with a honda lean-burn engine you better off making the intake temperature as cold as possible, so it stays a longer period in the lean-burn mode. (and reduce throttle losses, which is what you wanted to accomplish with the warm intake).

But this only applies to a certen point, becouse if the oil en general block temperatuur in winter don't become hot enough then the engine starts to enrich and is better of with a bit warmer intake to fool the other sensors and cut the enrichment. (till about 5 degrees celcius)

[beer]

To make sure a WAI helps you got to figure out what activates the lean-burn.

I'm traying to figure out, which sensor's and which readings are necessary to engage lean-burn.

-TPS signal 20% till 32% load.
-IAT above 5*Celcius
-ECT (coolend temp sensor) temp??? (Think above the warm-up mode from de IAC)
-Gear sensor???? (if there is such a thing in ower car) in 1st or 2nd gear even in the right rev and load range LB doesn't activate.
-RPM sensor, till 3000rpm but as stated above to low rpm disangages LB to but I think its lower than 2400rpm about 1750rpm
-RPM fluctuation sensor (located near the crank shaft), (instead of a wideband lambda sensor used in the d15z1).

-Probably MAP sensor
-There is no knock sensor in the d15z6
-Don't know about a Cat temp sensor, looked for one but couldn't find it.


To accomplish sustainable lean-burn, there has the be some sort of temprature control.
This is done throught the use of EGR.
The EGR exhaust fumes in de d-series honda come directly thought a hole in the exhaust port of the (thought) 1st cilinder.
This is the reason why the block warms up and the catalitic converter cools down.
I know that alot off lambda sensors need heat, and have internal heat coils.
That maybe a reason why its deactivates lean-burn, to warm up the lambda sensor.
The D15z6 got one an 1-wire lambdasonde so there's no heating applied.
According to my maintenaice manual it shift out of LB to check if the lambda still works, on the high way, you notice the sudden acceleration.

What i found remarkeble is that after accelerating, thus being out of LB, you don't enter LB very fast, but you can trigger it by giving it a short hit bit of extra load!?! and then lift of the throttle again.

Solution?:
I heard of slowing/altering the TPS sensor, I do think it helps to stay in lean burn but also delays fuel shut-off while decelerating and maybe dangerous for emerencies.

Has I wrote in the tread below, I think a "CAI"(after IAT) wouldt help to stay in lean burn till a certain point.
Becouse then you don't to give such alot of load and thus staying well below TPS 32%.
http://ecomodder.com/forum/showthrea...hx-8784-5.html
Has you probably know the IAT is located in the rubber inlet hose about 3inch infront of the throttle valve.
So Inlet manifold tempretures aren't measured directly.
This allows us to cool the intake manifold has much as possible, before freezing the fuel.
You only got to make a warm inlet for the warm-up period, making the evaporating pressure of the fuel less.

One could short cicuit the coolent lines throught the throttle body.
But the biggist heat source while in lean-burn is the EGR gasses.
I'm thinking of relocating the EGR inlet, from the exhaust valve hole to after the lambda or cat, making it possible to externaly cool the EGR gasses.
What I saw while looking at the inlet and head, is that there runs a coolend tube/hole next to the EGR in the block, thus cooling it a bit.