Header Change civic 2000 EK2
 

OK i got my new Civic EK2 2000 JDM hatch with a D13B Engine EFI All Stock.

If i change my header or i mean my entire exhaust system will i get better MPG??

and if i do it what u recommended for this little engine 2" pipes entire? and 4-2-1 header? can u help me with it?


and bout the intake i have to leave it stock or change it for another pipe and racing filter??

I don't want any loose i want to gain mpg.

I will change some part to carbon fiber like the hood.

If you drive with any concern for fuel economy, I don't think intake and exhaust will affect your fuel economy at all. Economical driving just doesn't move much air in or out.

There's a link in my sig about exhaust. It's a link to a decent thread with good points on both sides of the issue.

I have a Civic FK1, and my airfilter is at a point where I should change it: 32k km. Honda schedule says to change every 40k km. But mine is extremely black.
And you know what: it does not influences my fuel economy at all. And that's normal: I drive economical and need only a bit of air for my engine. Anyhow: the amount of air is measured after the airfilter, so only top BHP wil be influenced.
At this moment it's very hot weather here and my dashreading shows me the best mpg I ever had.
My advice: keep it stock.

Yeah, I replaced the old filter(fram?) with a drop-in K&N if I wanted more power(slight though it is), but it also makes the car more sensitive to FE gains and drops, meaning how you drive it will affect FE slightly more with a higher-flow rate filter than stock filter. The air gets in easier with same amount of throttle.

The air can't get in easier with the same amount of throttle...the throttle is limiting the air unless it's wide open (and even then, many vehicles filter flows more than their throttle).

If you want air to come in easier, open the throttle. That's free and actually works. You just have to shift low to limit your speed since you're no longer using the throttle for that job.

You have to stop thinking of the throttle as a fuel control; it's not, it's an air control. Fuel matches however much air gets in, no matter what makes it easier for that air to get in.

You're right on with the assessment. Still, WOT could cause some cars to shift into O/D and go rich with the mixture. Right?

If he drives the car the same way with a CAI > a stock, it would usually burn more gas. So, yes, he should change the way he uses the throttle.

With automatics it won't work (unless it faithfully obeys manual shift commands, and even then the torque converter changes how it all works). It definitely won't shift into O/D, and that's not good for FE.

Most cars (manual or auto) will go open loop and rich if you go WOT, but 75%-90% should be safe and the result is the same...completely removing the restriction.

That's pretty cool. I know a couple of people with scan gauges. I'd like it if it can help me monitor my driving habits. I may take on the project and get the DIY eventually. I'm not brave enough, yet. :D

Well, at least not until I get this car up to snuff in other areas.

ADDED: I'm still surprised that I'm getting 'solid' FE in the VX with the sensor on the fritz and a bad alternator(more than likely).

HC is right, but I like to ad that also at WOT the amount of air coming in is measured to adapt the amount of fuel to be injected. So in FE it won't change anything. Theoretically if more air can come in at WOT because of other filter you may even get a worser FE because you're producing more BHP (if driven often WOT).

Again, it doesn't work if you're producing more power; you must control your power by reducing the amount of air that the engine needs rather than the amount it can get...by keeping your RPM lower.

If you're producing excess power/work then it will be wasteful.

I use WOT every time I accelerate in my VW, and I get fantastic FE. In fact, even if I don't push the pedal to the floor the computer still opens the throttle all the way at low RPM anyway (I've been watching TPS on my ScanGauge). Presumably the engineers who programmed my throttle were aware of the advantage of opening the throttle.