Headers help gas mileage?

[SuperVX]

Has anyone installed a header to replace the stock exhaust/cat. convert. to help MPG? and gotten good results?

Afraid to mess with it. o2 sensor problems, etc...

Honda civic hatchback 1.5 liter engines


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[mkiVX]

Originally Posted by SuperVX

Has anyone installed a header to replace the stock exhaust/cat. convert. to help MPG? and gotten good results?

Afraid to mess with it. o2 sensor problems, etc...

Honda civic hatchback 1.5 liter engines

I swapped in a header and was not convinced because the o2 sensor readone port.

however I swapped in a actory SI 1.6 header/exhaust manifold and added a flexible exaust piece and was able to keep the car in in lean burn alot longer
i like the little extra power let me know if you are in socal i have 2 of the for sale

[GasSavers_Ryland]

I have not yet seen a header for a 1.5 liter Honda engine, all of the headers I've seen are to big to work well, at least according to the books on designing exhaust systems I've read, about 1.25" inside diamator would be about as large of an exhaust header tube diamtor that I would be willing to put on my car, and 2" seems to be what is out there.

[civic94]

I got a header on my dx motor, the mpg that i had before and after it was the same, but i do notice a bit more top end power and its a whole lot lighter than the cast iron OEM header

i really did it for the looks and weight savings taken off of the front end of the car

[R.I.D.E.]

In most cases performance mods are the opposite of what you want to do for efficiency.
In 1950 the Alfa grand prix motor got 390 HP out of 1500 cc at 2 miles per gallon.
My Vx is stock except for the reversed intake snorkel that draws hot air from the top radiator area. When I say stock it still has the original tires put on in 9-93, and just under 30k miles.
The cast iron manifold retains heat for hot air intake, which may offset any weight gain advantage.
My last three tanks were 62,55 (local), and 65.74 MPG.
Today when I merged on the uphill acceleration ramp to the interstate I hit 4500 RPM, I dont think it has been past 3 k in the last 1000 miles.

regards
gary

[SuperVX]

Thanks For The Replies Everybody!

[GasSavers_RoadWarrior]

Originally Posted by Ryland

I have not yet seen a header for a 1.5 liter Honda engine, all of the headers I've seen are to big to work well, at least according to the books on designing exhaust systems I've read, about 1.5" inside diamator would be about as large of an exhaust header tube diamtor that I would be willing to put on my car, and 2" seems to be what is out there.

Agreed...

I keep looking at electrical conduit, the steel pipe stuff, and wondering how long a header globbed together out of that would last... mostly as welding and fabbing practice and to test dimensions/results before spending out on the stainless steel bits to do it "properly".

[kamesama980]

the zinc anodizing will burn off (which is highly toxic) and then it'll rust quick. for prototyping purposes it'll probly be fine as long as you are in a highly ventilated area for cutting, welding, and running the car.

as for them helping gas mileage, most NA mods to a car (minor ones... not cams and crazy rpms) do help gas mileage to a point. it mostly depends on what the stock parts are like as to if there's a gain and how much. for headers: it's a LOT more helpfull to redo the rest of the exhaust system to match them. IE nice headers with the stock cat and cat-back won't do much. in cressidas/supras headers and full exhaust at 2.25" with quality mufflers will gain about 10-15% hp and improve 2-3 mpg all around because it's designed from the factory for in-town driving with a large car and luxury quiet. (supras have the exact same exhaust except for having a 1-in, 2-out muffler)

[My Goal: 55MPG]

Originally Posted by R.I.D.E.

In most cases performance mods are the opposite of what you want to do for efficiency.
In 1950 the Alfa grand prix motor got 390 HP out of 1500 cc at 2 miles per gallon.
My Vx is stock except for the reversed intake snorkel that draws hot air from the top radiator area. When I say stock it still has the original tires put on in 9-93, and just under 30k miles.
The cast iron manifold retains heat for hot air intake, which may offset any weight gain advantage.
My last three tanks were 62,55 (local), and 65.74 MPG.
Today when I merged on the uphill acceleration ramp to the interstate I hit 4500 RPM, I dont think it has been past 3 k in the last 1000 miles.

regards
gary

Agree.
Besides, you want to keep back pressure for that precious low end TQ.

Alex