Exhaust Experiment Prep Questions

[SVOboy]

So far I've got the stock exhaust and a Civic HF/CX/STD/VX (came off the CX) exhaust to test.

Anyway, I know A-B-A is good, and this'll be my first test ever, so I was just wondering, can I get away with not doing A-B-A, because depending on how hard the install is, I might die ripping it apart a bunch of times, though I could prolly use the practice,

Also, anyone else got exhausts to donate?

[krousdb]

A-B-A is best. But if you are planning on A-B-C-D then you really need to make sure that there are no other variables. A-B-A is best. Did I say that already?

[SVOboy]

Eh, I guess I'll get my header swap time down to 15 minutes, I guess I'll add it to my list of skillz that I can sell to people this summer,

I'll prolly do aba, but meh.

I need to find some exhausts to test, I can prolly borrow one from jared.

[MetroMPG]

I'd start with some easier data collection - get a baseline speed v. mpg graph.

But if you're set on looking at mods, I'm with Dan: A-B-A

If you can find a good level test route, and a calm day, I think you'll be surprised at how much the MPG readout can vary on multple runs (at the same speed) even when you change nothing at all.

It's also surprisingly difficult to hold a dead-even speed without cruise control.

The other thing is if you're changing things that take some time to replace, the drivetrain (not just engine, but bearings, tires, tranny, etc.) will cool down while you're working, so you need to make sure each test has enough warmup distance.

Have fun at graduation! Mine was a good time for sure. I remember it pretty well. A group of us ended the night with breakfast at my parents' house.

[GasSavers_Ryland]

how about doing A-B-C-D-A??? so you test all your exuast systems for however long you need to make sure you have a solid number, then switch, and after you test them all, go back to the first one, and make sure you still have the same number.

[SVOboy]

Eh, I dunno, I'll do something simple to practice up my testing skillz, I guess, *shrug*

[kwtorbe]

Would a performance tubular header, like a hedman made chikara tork-step header w/ equalizer in the 2 tube part of the 4-2-1 decrease or increase fuel economy? Less backpressure should increase efficiency, but maybe o2 sensor placement being further away and scaveging will allow more fuel to be used....Has anyone done this and found results one way or another?

[onegammyleg]

Hi kwtorbe - ?Less backpressure should increase efficiency?

There is a LOT more into exhaust system design that just backpressure.

What complicates the matter is a market place full of junk.
I have seen bought tubular headers (extractors) with wildly varying construction quality.
Some also had the wrong dimensions (tube lengths) suitable for the recomended application., and almost all had differing lengths between the tubes of the same set.
(Typically in a 4 into 1 extractor all of the 4 pipes will be of the same length.)

When required we made our own extractor systems and did them rite an dthere was a power improvement over other mass produced sets.

For FE applications never believe the makers of these exhaust parts FE test results.
Any FE increase from them is more likely come from exposing an extremly poor factory part.(eg a very tight crush bend)

Because of so many varying factors involved You will need to test these parts for yourself and see what works on your vehicle.- But I wouldnt spend too much money.

[kwtorbe]

Thanks gregW----I am planning on installing a Chikara tork-step header on my HX civic. I got it used and fairly cheap and really am just interested to see what if any improvements are made on FE. I like the hedman brand because I have used their headers on my old gas guzzling '68 Charger for horsepower and the quality was nice--mandrel bends were great. I need to get a MPG computer or something so I can tell more accurately what improvements different mods make other than always filling the tank and dividing the odometer reading by gallons....

[tomauto]

Be careful with that HX. where will you be putting the new Cat?